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Up: The fourth catalogue of Cloud


6 Notes on individual stars

These notes provide for 114 stars of the catalogue a sort of "identity card'', i.e. a short summary of the most important results published over the past years. Our survey of the literature covers essentially the last decade. Although we have attempted to be as complete as possible in this compilation, it cannot be excluded that a few papers escaped our attention.

BAT99-1 (Brey 1): Due to the weakness of the NIV $\lambda3480$ feature, Conti & Massey (1989) suggested that the spectral type WN2.5 or even WN2 could possibly be assigned to this star.

From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 1.9~R_{\odot}$; $T_{*} = 73 000~{\rm K}$; $\log(L/L_{\odot}) = 5.0$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.8$.
$R_{*} = 1.3~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) = 5.0$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6$.

The uncertainty results from the weakness of the HeI $\lambda5876$ emission line identified as a slightly increased continuum of 9 Å equivalent width.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.04$, over the range $1500-9000~{\mbox \AA}$. A spectrum of the star in the range $4500-6700~{\mbox \AA}$ is shown in Fig. 1 of the paper by Morgan, Watson & Parker (1992).

BAT99-2 (Brey 2): This star lies in the HeIII region discovered within the N 79 nebula by Pakull (1991) who assigned to the star the earliest WN type: WN1. An image of the region is given by Melnick & Heydari-Malayeri (1991).

According to Dopita et al. (1994), the ring nebula associated with the ${\rm W}-{\rm R}$ star is 23'' in diameter, has similar morphology to NGC 6888, and is brightest to the northwest. The HII region N 79 has a fine filamentary loop about 3' in diameter.

Garnett & Chu (1994) reported that the ${\rm W}-{\rm R}$ ejecta shell shows He and N abundances identical to the LMC interstellar values.

BAT99-3 (Brey 3): According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.84$, over the range $1500-9000~{\mbox \AA}$. This star is a borderline WN3 (Smith et al. 1996).

BAT99-4 (Brey 3a): According to Heydari-Malayeri et al. (1990), the nebula N 82 presents chemical abundances anomalies: nitrogen is enriched with respect to the average LMC value by a factor of 5, whereas oxygen is depleted by a factor 2.5. This very compact HII region seems to have been ejected by the central WC9-type ${\rm W}-{\rm R}$ star which is likely to be a member of a binary system, with an O-type companion. The ionizing source for N 82 is estimated to have an absolute magnitude Mv = -4.5 and an effective temperature $T_{\rm eff} = 36 000~{\rm K}$.

Moffat (1991) argued that the emission-line spectrum of N 82 does not contain a WC9 spectrum, a WNL or Of spectrum appears more likely.

On the basis of new observations, Heydari-Malayeri & Melnick (1992) indicated that the central star (or stars) of N 82 does not seem to be a canonical WC9 subclass.

The object is designated as Brey 3a by Lortet (1991).

BAT99-5 (Brey 4): No optical nitrogen ion lines being visible, Conti & Massey (1989) suggested that the spectral type WN1 could possibly be assigned to this star.

From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 1.8~R_{\odot}$; $T_{*} = 47 000~{\rm K}$; $\log(L/L_{\odot}) = 4.2$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -5.1$.
$R_{*} = 1.2~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) =
4.9$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.8$.
The uncertainty results from the weakness of the HeI $\lambda5876$ emission line ($W_{\lambda} = 8~{\mbox \AA}$).

A spectrum of the star in the range $4200-5300~{\mbox \AA}$ is shown in Fig. 1 of the paper by Morgan et al. (1992).

BAT99-6 (Brey 5): The star was classified O9f by Ardeberg et al. (1972). According to Walborn (1977), the broad HeII $\lambda4686$ and narrow NIV $\lambda4058$ emission present, indicate a WN component.

Dopita et al. (1994) noted that the star is embedded in the filamentary superbubble N 9; there is a filament of high excitation running in a north-south direction which clearly passes close to the ${\rm W}-{\rm R}$ star. No classical ring nebula is seen.

According to Niemela et al. (1995), the object appears to be a high-mass ($\sim\!\!80~M_{\odot}$) multiple system containing an eclipsing binary ($P\simeq$ 2 days) which primary component is not of spectral type WN but probably of type O3f*.

BAT99-7 (Brey 6): Breysacher (1981) classified this star as peculiar because of the unusually broad emission lines. Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 2.5~R_{\odot}$; $T_{*} = 90 000~{\rm K}$; $\log(L/L_{\odot}) = 5.6$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-3.8$.
These authors point out that the spectrum exhibits a very strong HeII emission at 5412 Å which has a larger equivalent width than the maximum reached in their standard grid of models. Therefore, they had to perform special calculations with 16 HeII levels for the analysis of this star.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.44$, over the range $1500-9000~{\mbox \AA}$.

BAT99-8 (Brey 8): Fehrenbach et al. (1976) noticed that star BE-159 is identified with WS 4 by Bohannan & Epps (1974) while on their finding chart the corresponding star is not WS 4.

Dopita et al. (1994) reported the existence of a large, faint, previously unrecognized ring nebula visible in [OIII], which is seen most clearly to the north and to the southeast of the star. This ring is estimated to be $150''
\times 230''$ in diameter.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.98$, over the range $1500-9000~{\mbox \AA}$.

BAT99-9 (Brey 7): Melnick & Heydari-Malayeri (1991) reported that an HeII image suggests the presence of a faint HeIII region near the star.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.80$, over the range $1500-9000~{\mbox \AA}$.

A spectrum of this star is shown in Fig. 1c.

BAT99-10 (Brey 9): The multiple nature of this object was soon recognized (cf. Westerlund & Smith 1964). The combined spectral type O9.5II:+WC5 assigned by Walborn (1977) could be clarified thanks to the speckle masking observations by Schertl et al. (1995). The core of the OB association LH 9 was resolved into 25 stellar components in a field of view of $6.4'' \times 6.4''$, and star No. 2 was identified without ambiguity with the ${\rm W}-{\rm R}$ component (see Fig. 2). Another study of this cluster = HD32228 has been presented by Bauer et al. (1996).

BAT99-11 (Brey 10): Fehrenbach et al. (1976) noticed that star BE-171 is identified with WS 6 by Bohannan & Epps (1974) while on their finding chart the corresponding star is not WS 6.

The star is in a superb ring nebula ($180'' \times 112''$ in diameter) discovered by Chu (1981); it has a measured expansion velocity of 45 km s-1 (Chu 1983).

According to Smith (1991), this star is twice as bright, in line and continuum, as any other WC4 star in the LMC.

BAT99-12 (Brey 10a): Star to which it is difficult to assign a unique spectral type. The notation f* is used by Walborn (1982a) to indicate that the NIV $\lambda4058$ emission is stronger than NIII $\lambda4634-4641$.

Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

BAT99-13: Crowther et al. (1995) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 20.5~R_{\odot}$; $T_{*} = 29 700~{\rm K}$; $\log(L/L_{\odot}) = 5.47$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.47.$
Pasquali et al. (1997) obtained for these parameters:
$R_{*}=19~R_{\odot}$; $T_{*}=33 000~{\rm K}$; $\log(L/L_{\odot}) = 5.6$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.09$, over the range $1500-9000~{\mbox \AA}$.

A spectrum of the star in the range $4000-4700~{\mbox \AA}$ is shown in Fig. 5 of the paper by Bohannan & Walborn (1989).

BAT99-15 (Brey 12): Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 2.3~R_{\odot}$; $T_{*} = 65 000~{\rm K}$; $\log(L/L_{\odot}) =
4.9$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.3.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.70$, over the range $1500-9000~{\mbox \AA}$.

Dopita et al. (1994) reported the discovery of the true ring nebula associated to this star, much a more compact filamentary shell, $103'' \times 130''$ in diameter, than the 8' across ring nebula claimed by Chu & Lasker (1980).

BAT99-16 (Brey 13): Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 15~R_{\odot}$; $T_{*}=33 000~{\rm K}$; $\log(L/L_{\odot}) = 5.3$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.4.$
Crowther & Smith (1997) obtained for these parameters:
$R_{*} = 16.7~R_{\odot}$; $T_{*} = 34 800~{\rm K}$; $\log(L/L_{\odot}) = 5.57$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.14.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.81$, over the range $1500-9000~{\mbox \AA}$.

Dopita et al. (1994) reported the discovery of a fine ring nebula, only $30'' \times 40''$ in diameter, probably representing stellar ejecta.

Garnett & Chu (1994) derived He/H and N/H in the ${\rm W}-{\rm R}$ ejecta shell approximately a factor of two higher than the LMC HII region values, and N/O more than a factor of 10 higher than the characteristic LMC value.

BAT99-17 (Brey 14): According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.25$, over the range $1500-9000~{\mbox \AA}$.

BAT99-18 (Brey 15): According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.17$, over the range $1500-9000~{\mbox \AA}$.

BAT99-19 (Brey 16): Breysacher (1981) classified the star as peculiar because of the unusually broad emission lines.

Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 6.2~R_{\odot}$; $T_{*} = 50 000~{\rm K}$; $\log(L/L_{\odot}) = 5.3$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.1.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.19$, over the range $1500-9000~{\mbox \AA}$.

Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found. According to Dopita et al. (1994), a faint filamentary nebula, $52''
\times 64''$ in diameter, is associated with the star and appears only in [OIII].

BAT99-20 (Brey 16a): Dopita et al. (1994) noted that the star is surrounded by a small and bright ring nebula, 18'' in diameter, seen best in [OIII].

According to Bartzakos (1998), the absorption-line

spectrum might arise in a visual OB companion, therefore the star is considered as "almost certainly single''.

BAT99-21 (Brey 17): According to Dopita et al. (1994), there is a faint nebula, 56'' in diameter, associated with the star.

BAT99-22 (Brey 18): According to Allen & Glass (1976), a late-type supergiant component provides the near-infrared flux. Cowley & Hutchings (1978) confirmed the presence of said component spectroscopically and classified it M2Ia. Stahl et al. (1984) found that the star is related to the S Dor variables. According to Crowther et al. (1995), the star is probably a dormant LBV, or at a stage immediately after this phase.

Schmutz et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 30~R_{\odot}$; $T_{*} = 28 500~{\rm K}$; $\log(L/L_{\odot}) = 5.7$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6$.

Crowther et al. (1995) obtained very similar stellar parameters:
$R_{*} = 33.8~R_{\odot}$; $T_{*} = 28 500~{\rm K}$; $\log(L/L_{\odot}) = 5.83$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.40.$
Pasquali et al. (1997) obtained for these parameters:
$R_{*}=25~R_{\odot}$; $T_{*} = 35 200~{\rm K}$; $\log(L/L_{\odot}) = 5.9$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.5.$
Dopita et al. (1994) pointed out that the arcs of nebulosity seen in H$\alpha$ are not visible in [OIII]. Nota et al. (1996) reported the presence of strong nebular emission lines in the spectrum of BAT99-22 pointing out, however, that on the basis of the spectroscopic data alone no conclusion can be made about the physical association of the detected nebula with the star.

A spectrum of the star in the range $3900-4700~{\mbox \AA}$ is shown in Fig. 3 of the paper by Bohannan & Walborn (1989).

BAT99-23: This star (MG 9) was recently discovered by Morgan (1999). It is one of the faintest ${\rm W}-{\rm R}$ stars in the LMC, however this unusual faintness is not intrinsic but due to extinction. The HeII $\lambda4686$ line is weaker than in most LMC WN3 stars.

BAT99-24 (Brey 19): According to Dopita et al. (1994), there is a large ring nebula in both [OIII] and H$\alpha$, some $135'' \times 160''$ in diameter, brightest to the southwest.

BAT99-25 (Brey 19a): This ${\rm W}-{\rm R}$ star, discovered by Morgan & Good (1990), lies outside the area searched by Azzopardi & Breysacher (1980). The object is designated as Brey 19a by Lortet (1991) who erroneously identified it as BE-456. The correct identification is BE-546.

BAT99-26 (Brey 20): Dopita et al. (1994) reported the discovery of a very small ring nebula, $12'' \times 19''$ in diameter, associated with the star. A spectrum of this star is shown in Fig. 1a.

BAT99-27 (Brey 21): The star is located in an apparent association which includes the compact cluster HD 35342, S Doradus (HD 35343) and HDE 269357 (Walborn 1977).
According to Smith et al. (1996), CIV $\lambda5808 \sim$ HeII $\lambda5411$indicates WN5 rather than WN3; a plateau of emission longward of HeII $\lambda4686$ is unidentified and unusual.

BAT99-28 (Brey 22): It is a confirmed binary system of period P = 14.926 days (Moffat et al. 1990); a spectrum in the range $4000-7000~{\mbox \AA}$ is shown in Fig. 1 of their paper.

According to Dopita et al. (1994), no nebular features appear to be associated with the star.

BAT99-29 (Brey 23): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found. Dopita et al. (1994) confirmed that no nebular features are associated with the ${\rm W}-{\rm R}$ star itself.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.74$, over the range $1500-9000~{\mbox \AA}$.

BAT99-30 (Brey 24): Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 13~R_{\odot}$; $T_{*}=33 000~{\rm K}$; $\log(L/L_{\odot}) = 5.2$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.5.$
Crowther & Smith (1997) obtained fairly similar stellar parameters:
$R_{*} = 12.6~R_{\odot}$; $T_{*}=36 400~{\rm K}$; $\log(L/L_{\odot}) = 5.40$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.60.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.99$, over the range $1500-9000~{\mbox \AA}$.

BAT99-31 (Brey 25): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.74$, over the range $1500-9000~{\mbox \AA}$.

BAT99-32 (Brey 26): According to Moffat (1989), it is a binary system of period P= 1.9075 days.

Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 17~R_{\odot}$; $T_{*}=33 000~{\rm K}$; $\log(L/L_{\odot}) = 5.5$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.2.$
Crowther & Smith (1997) obtained fairly similar stellar parameters:
$R_{*} = 16.9~R_{\odot}$; $T_{*} = 35 300~{\rm K}$; $\log(L/L_{\odot}) = 5.60$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.12$,assuming that the visual spectrum of the object is entirely due to the ${\rm W}-{\rm R}$ star.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.24$, over the range $1500-9000~{\mbox \AA}$.
Dopita et al. (1994) reported the discovery of a very small ring nebula, 16'' in diameter, which appears as a bright knot in H$\alpha$ to the east of the star, and as an arc of nebulosity to the south.

A spectrum of this star is shown in Fig. 1b.

BAT99-33: It is remarkable that this star, now classified Ofpe/WN9, was already included in the list of ${\rm W}-{\rm R}$ stars recognised by Miss Cannon and Miss Payne (cf. Buscombe et al. 1954).
Pasquali et al. (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*}=39~R_{\odot}$; $T_{*} = 34 800~{\rm K}$; $\log(L/L_{\odot}) = 6.3$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.19$, over the range $1500-9000~{\mbox \AA}$.

Nota et al. (1996) reported the existence of a surrounding nebulosity.

A spectrum of the star in the range $3900-4700~{\mbox \AA}$ is shown in Fig. 4 of the paper by Bohannan & Walborn (1989).

BAT99-35 (Brey 27): From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 5.5~R_{\odot}$; $T_{*} = 39 000~{\rm K}$; $\log(L/L_{\odot}) = 4.8$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6.$
$R_{*} = 3.0~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) = 5.7$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.3.$
These authors point out that the stellar parameters corresponding to the first entry appear to be unrealistic given the WN3 spectral type of the star; the presence of the HeI $\lambda5876$ line is questioned.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.58$, over the range $1500-9000~{\mbox \AA}$.

Possibly a borderline WN4 according to Smith et al. (1996).

BAT99-36 (Brey 29): The CIV $\lambda5808$ emission line is unusually strong for a WN-type star (Breysacher 1981). A spectrum of this star is shown in Fig. 1a.

Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 4.0~R_{\odot}$; $T_{*} = 47 000~{\rm K}$; $\log(L/L_{\odot}) =
4.9$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.3.$
Crowther et al. (1995), found very similar stellar parameters from their standard model A analysis, however, in view of the possible contamination of the ${\rm W}-{\rm R}$ line spectrum by a companion, they performed a second analysis (model B) which takes into account the binarity. The revised parameters then obtained are as follows:
$R_{*} = 3~R_{\odot}$; $T_{*} = 63 000~{\rm K}$; $\log(L/L_{\odot}) = 5.0$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.3.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.69$, over the range $1500-9000~{\mbox \AA}$.

Chu & Lasker (1980) identified DEM 174 as a ring nebula, however, according to Dopita et al. (1994) higher resolution images do not show any shell structure. Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

BAT99-37 (Brey 30): Dopita et al. (1994) reported the discovery of a small ring nebula, $26'' \times 42''$ in diameter, extended in the north-south direction.

BAT99-38 (Brey 31): It is a confirmed binary system of period P = 3.03269 days (Moffat et al. 1990); a spectrum in the range $4000-7000~{\mbox \AA}$ is shown in Fig. 2 of their paper.

Dopita et al. (1994) reported the discovery of a filamentary ring nebula, 33'' in diameter, visible in [OIII]. In H$\alpha$ a complex nebula in the form of a series of connected loops extends to the south-southwest.

BAT99-39 (Brey 32): It is a confirmed binary system of period P = 1.91674 days (Moffat et al. 1990); a spectrum in the range $4000-7000~{\mbox \AA}$ is shown in Fig. 3 of their paper. According to Seggewiss et al. (1991), the orbital inclination is too low to allow detectable transparency eclipses.

BAT99-40 (Brey 33): According to Smith et al. (1996), the ${\rm W}-{\rm R}$ spectrum is heavily affected by an O absorption spectrum.

BAT99-41 (Brey 35): According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.73$, over the range $1500-9000~{\mbox \AA}$.

BAT99-42 (Brey 34): Seggewiss et al. (1991) remarked that the fairly long spectroscopic period of this star (P=30.18: days) is still poorly known.

Dopita et al. (1994) reported the presence of a clearly defined filamentary ring nebula, 49'' in diameter, brightest in two arcs to the northwest and to the southeast.

According to Smith et al. (1996), CIV $\lambda5808 \sim$ HeII $\lambda5411$indicates WN5 rather than WN3; a plateau of emission longward of HeII $\lambda4686$ is unidentified and unusual.

BAT99-43 (Brey 37): From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 8.5~R_{\odot}$; $T_{*} = 35 000~{\rm K}$; $\log(L/L_{\odot}) = 5.0$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.5.$
$R_{*} = 5.1~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) =
6.2$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.3.$
These authors point out that the stellar parameters corresponding to the first entry appear to be unrealistic given the spectral type of the star; the presence of the HeI $\lambda5876$ line is questioned.

Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found. Dopita et al. (1994) reported the possible presence of a very faint, small ring nebula in [OIII], 13'' in diameter, and brightest on the east side of the star.

According to Moffat (1998), BAT99-43 is a short-period (SB2) binary system.

BAT99-44 (Brey 36): Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 13.4~R_{\odot}$; $T_{*} = 33 700~{\rm K}$; $ \log(L/L_{\odot}) = 5.32$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.74.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.07$, over the range $1500-9000~{\mbox \AA}$.

BAT99-45: Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 30.3~R_{\odot}$; $T_{*} = 29 200~{\rm K}$; $\log(L/L_{\odot}) = 5.78$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.30.$
Pasquali et al. (1997) obtained for these parameters:
$R_{*} = 32~R_{\odot}$; $T_{*} = 32 100~{\rm K}$; $\log(L/L_{\odot}) = 6.0$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.3.$
A spectrum of the star in the range $3900-4700~{\mbox \AA}$ is shown in Fig. 3 of the paper by Bohannan & Walborn (1989).

According to van Genderen & Sterken (1996), the observed light variations of BAT99-45 show a timescale of 1-2 years and have an amplitude of 0.3-0.5 mag, which points to an LBV near minimum light. The colour variation is also typical for an LBV.

BAT99-46 (Brey 38): According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.03$, over the range $1500-9000~{\mbox \AA}$.

BAT99-48 (Brey 40): Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 2.9~R_{\odot}$; $T_{*} = 57 000~{\rm K}$; $\log(L/L_{\odot}) =
4.9$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.5.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.52$, over the range $1500-9000~{\mbox \AA}$.

BAT99-49 (Brey 40a): Niemela (1991) found this object to be a double-lined binary with an elliptic orbit (e=0.41) of period about 34 days. Niemela et al. (1991) also reported the detection of nebular HeII $\lambda4686$ line emission over a region having an extent of 70''. According to Dopita et al. (1994), the star is surrounded by a circular ring nebula in H$\alpha$, some 40'' in diameter.

BAT99-52 (Brey 43): According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.18$, over the range $1500-9000~{\mbox \AA}$.

BAT99-53 (Brey 44): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found. According to Niemela (1995), this star shows radial velocity variations of emission and absorption lines in opposite sense indicating a long-period binary.

BAT99-54 (Brey 44a): Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*}=20.0~R_{\odot}$; $T_{*} = 30 900~{\rm K}$; $\log(L/L_{\odot}) = 5.52$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-5.01.$

BAT99-55: Crowther & Smith (1997) derived, from their model A analysis, the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 32.6~R_{\odot}$; $T_{*} = 27 900~{\rm K}$; $\log(L/L_{\odot}) = 5.76$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.87.$
Pasquali et al. (1997) obtained for these parameters:
$R_{*}=35~R_{\odot}$; $T_{*} = 30 900~{\rm K}$; $\log(L/L_{\odot}) = 6.0$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6.$
A spectrum of the star in the range $3900-4700~{\mbox \AA}$ is shown in Fig. 3 of the paper by Bohannan & Walborn (1989).

According to Nota et al. (1996), the radial velocity map of the circumstellar nebula ($7.7'' \times 8.6''$ in size, and showing a bipolar morphology) is clearly consistent with a hollow shell expanding at $\sim$ 30 km s-1.

BAT99-56 (Brey 46): This star is noted as variable by Feitzinger & Isserstedt (1983).

Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.04$, over the range $1500-9000~{\mbox \AA}$.

BAT99-58 (Brey 47): Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 10~R_{\odot}$; $T_{*} = 34 000~{\rm K}$; $\log(L/L_{\odot}) = 5.1$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.8.$
Crowther & Smith (1997) obtained fairly similar stellar parameters:
$R_{*} = 11.4~R_{\odot}$; $T_{*} = 35 700~{\rm K}$; $\log(L/L_{\odot}) = 5.28$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.70.$
A spectrum of the star in the range $4200-5300~{\mbox \AA}$ is shown in Fig. 1 of the paper by Morgan et al. (1992).

BAT99-59 (Brey 48): From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 15~R_{\odot}$; $T_{*} = 40 000~{\rm K}$; $\log(L/L_{\odot}) = 5.7$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.4.$
$R_{*} = 8.2~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) =
6.6$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.2.$
These authors point out that the HeI $\lambda5876$ emission is below safe detection, therefore the determined temperature (first entry) corresponds to the limit below which the HeI $\lambda5876$ line would start to become visible.

A superb ring nebula studied by Chu & Lasker (1980). According to Dopita et al. (1994), the inner filamentary ring of swept-up matter has a diameter of $80'' \times 97''$, while the outer, more diffuse parts can be traced out to a distance of 115'' from the exciting star.

BAT99-60 (Brey 49): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

BAT99-61 (Brey 50): According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.98$, over the range $1500-9000~{\mbox \AA}$.

BAT99-62 (Brey 51): A fine partial ring nebula, of diameter $\sim45''$(Dopita et al. 1994), appearing as a bright arc to the north of the star was discovered by Pakull (1991).

Possibly a borderline WN4 according to Smith et al. (1996).

BAT99-63 (Brey 52): Cowley et al. (1984) found no evidence for binary motion, but noted the high velocity of the star, possibly a "runaway''.

From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 5.9~R_{\odot}$; $T_{*} = 35 000~{\rm K}$; $\log(L/L_{\odot}) = 4.6$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.9.$
$R_{*} = 3.1~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) =
5.8$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.7.$
These authors point out that the HeI $\lambda5876$ emission is below safe detection, therefore the determined temperature (first entry) corresponds to the limit below which the HeI $\lambda5876$ line would start to become visible.

A ring nebula was claimed for this object by Chu & Lasker (1980). According to Dopita et al. (1994), they identified the bright HII region to the northeast as a ring nebula, whereas it is apparent that the true nebula is a fine filamentary ring $65'' \times 88''$ in diameter.

BAT99-64 (Brey 53): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

BAT99-65 (Brey 55): Dopita et al. (1994) reported the discovery of a ring nebula elongated in the northwest to southeast direction, $20'' \times
29''$ in diameter. The outer filamentary shell has a fainter shell inside of diameter 12''.

BAT99-67 (Brey 56): This star is noted as variable by Feitzinger & Isserstedt (1983). According to Smith et al. (1996) it is a binary with an OB component.

From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*}=16~R_{\odot}$; $T_{*}=32 000~{\rm K}$; $\log(L/L_{\odot}) = 5.4$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.3.$
$R_{*}=8.9~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) =
6.7$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6.$
These authors point out that the HeI $\lambda5876$ emission is below safe detection, therefore the determined temperature (first entry) corresponds to the limit below which the HeI $\lambda5876$ line would start to become visible.

According to Dopita et al. (1994), there is a flocculent nebulosity associated with the star, 40'' in diameter. This is contained within the X-ray superbubble 0536-692 (Mathewson et al. 1985), which is part of N 157.

BAT99-68 (Brey 58): This star is located in the tight cluster $\alpha$ in the western part of LH90. A spectrum in the range $3800-6800~{\mbox \AA}$ is shown in Fig. 2a of the paper by Testor et al. (1993) who derived a WN6-7 spectral type. The star is classified Of by Smith et al. (1996).

BAT99-69: This star is located in the tight cluster $\alpha$ in the western part of LH90. A spectrum in the range $3800-6800~{\mbox \AA}$ is shown in Fig. 2b of the paper by Testor et al. (1993).

BAT99-71 (Brey 60): Smith et al. (1996) pointed out that the HeII emission lines are weak and very narrow for a WN3; they classified the star as peculiar.

BAT99-76 (Brey 64): A spectrum of the star in the range $3900-4700~{\mbox \AA}$ is shown in Fig. 3 of the paper by Bohannan & Walborn (1989), and in the range $4000-7500~{\mbox \AA}$ in Fig. 1b of the present paper.

Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*}=19~R_{\odot}$; $T_{*}=30 000~{\rm K}$; $\log(L/L_{\odot}) = 5.4$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6.$
Crowther et al. (1995) obtained fairly similar stellar parameters:
$R_{*} = 20.8~R_{\odot}$; $T_{*}=30 600~{\rm K}$; $\log(L/L_{\odot}) = 5.54$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.65.$
Pasquali et al. (1997) obtained for these parameters:
$R_{*} = 18~R_{\odot}$; $T_{*} = 38 700~{\rm K}$; $\log(L/L_{\odot}) =
5.8$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.7.$
According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.17$, over the range $1500-9000~{\mbox \AA}$.

Nota et al. (1996) reported the existence of a surrounding shell which expands at a velocity of $\sim\!\!30$ km s-1. According to Pasquali, Nota & Clampin (1998), two diffuse arches define the shell of diameter 13'', which is not of stellar origin and probably represents the relic of the interstellar bubble blown by the star during its O main-sequence phase.

BAT99-77 (Brey 65): This star is located in the tight cluster $\beta$ = HD 269828 in the western part of LH90. Moffat (1989) showed that the star is a binary system with a period P = 3.0032 days. Spectral variations in the range $4000-4800~{\mbox \AA}$ are illustrated in Fig. 3 of the paper by Heydari-Malayeri et al. (1993).

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.46$, over the range $1500-9000~{\mbox \AA}$.

BAT99-78 (Brey 65b): This star is located in the tight cluster $\beta$ = HD 269828 in the western part of LH90. A spectrum in the range $3700-5500~{\mbox \AA}$ is shown in Fig. 5 of the paper by Testor & Schild (1990).

The object is designated as Brey 65b by Lortet (1991).

The composite nature of this star was recognized by Heydari-Malayeri et al. (1993), and confirmed by HST/WFC observations (Walborn et al. 1995) which further resolved the object into five components. According to Walborn et al. (1998), the WN star is definitely component 5C. The HST image of BAT99-78 is reproduced in Fig. 8.

BAT99-79 (Brey 57): A spectrum of the star in the range $4000-4800~{\mbox \AA}$ is shown in Fig. 3 of the paper by Heydari-Malayeri et al. (1993).

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.88$, over the range $1500-9000~{\mbox \AA}$.

BAT99-80 (Brey 65c): This star is located in the tight cluster $\beta$ = HD 269828 in LH90 and its spectrum, in the range $3700-5500~{\mbox \AA}$, is shown in Fig. 5 of the paper by Testor & Schild (1990).

The object is designated as Brey 65c by Lortet (1991).

BAT99-81 (Brey 65a): This ${\rm W}-{\rm R}$ star was discovered serendipitously by Cowley et al. (1984) who reported a significant decrease in intensity of the emission spectrum on one night (JD 2445732).

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 3.10$, over the range $1500-9000~{\mbox \AA}$.

BAT99-82 (Brey 66): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

A spectrum of the star in the range $4500-6700~{\mbox \AA}$ is shown in Fig. 1 of the paper by Morgan, Watson & Parker (1992).

BAT99-83: This star is now categorized as a Luminous Blue Variable. According to Nota et al. (1991), it is a very luminous ($L \approx 10^{6} L_{\odot}$) star with an initial mass between $60~M_{\odot}$ and $100~M_{\odot}$.

Smith et al. (1998) found that the circumstellar environment of BAT99-83 reveals two discrete ejections in the mass loss history of the central star. There is an inner expanding shell, with a radius of 0.6 pc, an expansion velocity of 29 km s-1,and a dynamical age of $2\,10^{4}$ years. There is also material beyond the bright inner nebula that may represent an outer expanding shell with a radius of 1.9 pc and a dynamical age of $7\,10^{4}$ years.

BAT99-84 (Brey 68): According to Bartzakos (1998), the absorption-line spectrum might arise in a visual OB companion, therefore the star is considered as "almost certainly single''.

BAT99-85 (Brey 67): According to Bartzakos (1998), the absorption-line spectrum might arise in a visual OB companion, therefore the star is considered as "almost certainly single''.

BAT99-87 (Brey 70): According to Bartzakos (1998), the absorption-line spectrum might arise in a visual OB companion, therefore the star is considered as "almost certainly single''.

BAT99-88 (Brey 70a): According to Lortet et al. (1991), this star is outstanding by its high luminosity ($M_{\rm bol} \approx -10.0$), high reddening, strong and wide lines, and intense CIV $\lambda5808$ emission.

BAT99-89 (Brey 71): Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*}=9.4~R_{\odot}$; $T_{*} = 39 400~{\rm K}$; $\log(L/L_{\odot}) = 5.28$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.35.$
According to Dopita et al. (1994), a dust arc - possibly a swept-up shell - appears 20'' to the north of the star in projection against the bright HII region.

BAT99-90 (Brey 74): A spectrum of the star in the range $4500-6700~{\mbox \AA}$ is shown in Fig. 1 of the paper by Morgan et al. (1992).

BAT99-91 (Brey 73): This star is a complex multiple system in LH99 and was resolved into 12 components by Testor et al. (1988), who achieved 0.25'' resolution. HST/WFC observations of the object (Walborn et al. 1995) further resolved into four components each the two brightest components, Nos. 1, (the WN) and 2, identified by Testor et al. (1988). According to Walborn et al. (1998), the WN star is definitely component 1A. The HST image of BAT99-91 is reproduced in Fig. 10.

BAT99-92 (Brey 72): This star is noted as variable in V by Feitzinger & Isserstedt (1983). Although the ${\rm W}-{\rm R}$ component is generally classified WN, the width of the HeII $\lambda4686$ emission and the strength of the CIV $\lambda5808$ line probably explain that a WC type has sometimes been assigned as well. The spectral type given in Table 2 is the one determined by Moffat & Seggewiss (1986) who argued that, unless one of the star has a very peculiar mass, the WN6 component must be orbiting a third, unseen star (P = 4.3092 days), which is most likely a normal luminosity O star of moderate mass, similar to the mass of the WN6 star. Seggewiss et al. (1991) remarked, however, that the light curve shows no convincing evidence for variation with the ${\rm W}-{\rm R}$ star's orbital period.

Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

BAT99-93 (Brey 74a): The object is designated as Brey 74a by Lortet (1991).

BAT99-94 (Brey 85): Breysacher (1981) classified this star as peculiar because of the unusually broad emission lines.

Koesterke et al. (1991) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 1.8~R_{\odot}$; $T_{*} = 90 000~{\rm K}$; $\log(L/L_{\odot}) = 5.3$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.0.$
Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

BAT99-95 (Brey 80): Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 15.2~R_{\odot}$; $T_{*} = 36 100~{\rm K}$; $\log(L/L_{\odot}) = 5.55$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -3.70.$
Located in the vicinity of the core of 30 Doradus, BAT99-95 has a peculiar spectral appearance among the WNL stars with strong, broad non-Gaussian profiles.

According to Dopita et al. (1994), this star does not appear to be associated with ring features.

BAT99-96 (Brey 81): Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*}=27.0~R_{\odot}$; $T_{*} = 32 400~{\rm K}$; $\log(L/L_{\odot}) = 5.86$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.02.$
These authors noted that, relative to the other LMC WN8 stars, BAT99-96 shows a high luminosity and very low hydrogen content of H/He $\sim 0.2$. According to Dopita et al. (1994), this star does not appear to be associated with ring features.

BAT99-98 (Brey 79): Star located near the core of 30 Doradus.

BAT99-99 (Brey 78): Star located near the core of 30 Doradus.

BAT99-100 (Brey 75): Star located near the core of 30 Doradus. Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*}= 25.9~R_{\odot}$; $T_{*} = 33 100~{\rm K}$; $\log(L/L_{\odot}) = 5.86$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.11.$

BAT99-101+102+103 (Brey 87): According to Moffat et al. (1987), the visual multiple system R 140, in the 30 Doradus nebula, contains at least three ${\rm W}-{\rm R}$ stars, one of type WC5, the others of type WNL. BAT99-101 $\equiv$ R 140a1 (northern component of R 140a) and BAT99-102 $\equiv$ R 140a2 (southern component of R 140a) are not resolved on the finding chart (Fig. 12). One of the WNL components (BAT99-102) is found to be a close spectroscopic binary with a period of 2.76 days.

Dopita et al. (1994) noted that the system does not appear to be associated with ring features.

BAT99-104 (Brey 76): Star located near the core of 30 Doradus. In the notation introduced by Melnick (1985) and refined by Parker (1993), the object is subdivided into two components: Mk 37Wa and Mk 37Wb. According to Massey & Hunter (1998), the ${\rm W}-{\rm R}$ spectrum originates from Mk 37Wb.

BAT99-105 (Brey 77): Star located near the core of 30 Doradus. Heap et al. (1991) derived the following properties for this star: $T_{\rm eff} = 42 500~{\rm K}$; $R = 26~R_{\odot}$; $\log(L/L_{\odot}) = 6.36$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -5.4.$
These authors noted that with a present mass of $100~M_{\odot}$,BAT99-105 is one of the most luminous and massive stars known. A detailed NLTE analysis of this star has been presented by de Koter et al. (1997).

BAT99-107 (Brey 86): Hyland et al. (1978) detected an infrared excess (V-K)0=1.41 for this star, which is much larger than normally found in galactic WN stars.

According to Moffat (1989), this object, which exhibits a "nonpure'' ${\rm W}-{\rm R}$spectrum, is a spectroscopic binary. It appears to have been responsible for producing a very bright and fine ring nebula, $49'' \times 55''$ in diameter, brightest on the east and extending to the northwest (Dopita et al. 1994).

BAT99-106+108+109+110+111+112 (Brey 82): Central cluster of 30 Dor. Speckle interferometric observations (Weigelt & Baier 1985) and later HST/FOC images (Weigelt et al. 1991) have resolved R 136a - the bright, diffuse central object - into a minimum of eight components (R 136a1$\rightarrow$a8), all within 1''.
From HST spectroscopy, Crowther & Dessart (1998) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the stars:
$\bullet$ BAT99-108 (R 136a1): $R_{*}=20~R_{\odot}$; $T_{*}=45 000~{\rm K}$; $\log(L/L_{\odot}) = 6.18$;
$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.43.$
$\bullet$ BAT99-109 (R 136a2): $R_{*}=19~R_{\odot}$; $T_{*} = 46 000~{\rm K}$; $\log(L/L_{\odot}) = 6.16$;
$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.57.$
$\bullet$ BAT99-106 (R 136a3): $R_{*}=19~R_{\odot}$; $T_{*} = 44 000~{\rm K}$; $\log(L/L_{\odot}) = 6.07$;
$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.27.$

From HST observations (WFPC photometry and GHRS spectroscopy), Heap et al. (1994) derived the following properties for BAT99-110 (R 136a5) : $T_{\rm eff} = 42 500~{\rm K}$; $R = 16.4~R_{\odot}$; $\log(L/L_{\odot}) =
5.90$; $M \approx 50~M_{\odot}$. These authors noted that the observed mass-loss rate, $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.74$, is an order of magnitude higher than assumed by current stellar evolutionary models.

A detailed NLTE analysis of stars in R 136a has been presented by de Koter et al. (1997).

BAT99-113: Star located near the core of 30 Doradus.

BAT99-114: Star located near the core of 30 Doradus.

BAT99-115 (Brey 83): Star located near the core of 30 Doradus. In the notation introduced by Melnick (1985) and refined by Parker (1993), the object is subdivided into three components: Mk 33Sa, Mk 33Sb and Mk 33Sc. The ${\rm W}-{\rm R}$ star corresponds to Mk 33Sb.

BAT99-116 (Brey 84): Star located near the core of 30 Doradus.

BAT99-117 (Brey 88): From an analysis of the helium spectrum, Koesterke et al. (1991) have derived the following set of values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 17~R_{\odot}$; $T_{*}=33 000~{\rm K}$; $\log(L/L_{\odot}) = 5.5$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.5.$
$R_{*} = 9.2~R_{\odot}$; $T_{*} = 90 000~{\rm K}$ (adopted); $\log(L/L_{\odot}) =
6.7$; $\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.7.$
These authors point out that the HeI $\lambda5876$ emission is below safe detection, therefore the determined temperature (first entry) corresponds to the limit below which the HeI $\lambda5876$ line would start to become visible.

Dopita et al. (1994) noted that this star is contained within the X-ray-emitting supershell on the northeast side of 30 Dor.

According to Smith et al. (1996), strong Balmer absorption lines are present in the spectrum, but no helium absorption lines.

BAT99-118 (Brey 89): Crowther & Dessart (1998) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 36~R_{\odot}$; $T_{*} = 37 000~{\rm K}$; $\log(L/L_{\odot}) = 6.34$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -3.82.$

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.93$, over the range $1500-9000~{\mbox \AA}$.

Dopita et al. (1994) noted that this star is contained within the X-ray-emitting supershell on the northeast side of 30 Dor.

BAT99-119 (Brey 90): According to Moffat (1989), it is a binary system of period P= 25.17: days.

Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 39.5~R_{\odot}$; $T_{*} = 31 800~{\rm K}$; $\log(L/L_{\odot}) = 6.16$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -3.84.$
These stellar parameters compare closely with those of BAT99-118, its neighbour in 30 Doradus.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.79$, over the range $1500-9000~{\mbox \AA}$.

BAT99-120 (Brey 91): Dopita et al. (1994) reported the discovery of a very large filamentary and "cellular'' ring nebula, $\sim 240''$ in diameter.

Possibly a post-LBV according to Crowther et al. (1995) who derived the following stellar parameters:
$R_{*} = 26.3~R_{\odot}$; $T_{*}=30 000~{\rm K}$; $\log(L/L_{\odot}) = 5.70$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.51.$
Pasquali et al. (1997) obtained for these parameters:
$R_{*} = 23~R_{\odot}$; $T_{*} = 38 900~{\rm K}$; $\log(L/L_{\odot}) = 6.0$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.6.$
Nota et al. (1996) reported the presence of strong nebular emissions in the spectrum of BAT99-120 pointing out, however, that the association of these lines with the star is less obvious. This star is located only 3'' west of Sk -69 249.

BAT99-122 (Brey 92): Hyland et al. (1978) detected an infrared excess (V-K)0= 2.10 for this star, which is much larger than normally found in galactic WN stars.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.79$, over the range $1500-9000~{\mbox \AA}$.

Dopita et al. (1994) noted that this star is contained within the X-ray-emitting supershell on the northeast side of 30 Dor.

BAT99-123 (Brey 93): According to Melnick & Heydari-Malayeri (1991), the star is embedded in a bright HII region having a very complex structure in [OIII]. The absence of HeII $\lambda4686$ nebular emission in the ring nebula around the star was noted by Pakull (1991). A spectrum of this star is shown in Fig. 1c.

BAT99-124 (Brey 93a): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

Dopita et al. (1994) reported the discovery of a small asymmetric ring nebula, $\sim 20''$ in diameter, brightest to the east.

BAT99-126 (Brey 95): This star is noted as variable in V by Feitzinger & Isserstedt (1983).

Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

BAT99-130: Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 28.4~R_{\odot}$; $T_{*} = 28 400~{\rm K}$; $\log(L/L_{\odot}) = 5.67$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.80.$
A spectrum of the star in the range $3900-4700~{\mbox \AA}$ is shown in Fig. 3 of the paper by Bohannan & Walborn (1989).

BAT99-132 (Brey 99): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 1.96$, over the range $1500-9000~{\mbox \AA}$.

BAT99-133: Walborn (1982b) considered this star to be a spectroscopic twin to R 127 (BAT99-83) in minimum.

Crowther & Smith (1997) derived the following values for the "core radius'' R*, the related effective temperature T*, the luminosity L and the mass-loss rate $\dot{M}$ of the star:
$R_{*} = 33.3~R_{\odot}$; $T_{*} = 28 300~{\rm K}$; $\log(L/L_{\odot}) = 5.76$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1})) = -4.96,$
and obtained, after nebular subtraction, a relatively low hydrogen content of H/He $\sim 1.2$.
Pasquali et al. (1997) obtained for these parameters:
$R_{*} = 28~R_{\odot}$; $T_{*} = 36 100~{\rm K}$; $\log(L/L_{\odot}) = 6.1$;$\log(\dot{M}/(M_{\odot}~{\rm yr}^{-1}))=-4.7.$
Pasquali et al. (1998) have spatially resolved the circumstellar nebula associated wit BAT99-133. The nebula has the appearance of a shell, 7.6'' in diameter, having a velocity expansion of 28 km s-1, which indicates a dynamical age of $\sim$ 30000 years.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.73$, over the range $1500-9000~{\mbox \AA}$.

A spectrum of the star in the range $3900-4700~{\mbox \AA}$ is shown in Fig. 3 of the paper by Bohannan & Walborn (1989).

BAT99-134 (Brey 100): Niemela et al. (1991) reported that from their systematic search for high excitation nebulae around ${\rm W}-{\rm R}$ stars in the Magellanic Clouds, no evidence for nebular HeII $\lambda4686$ emission in the vicinity of the star could be found.

According to Morris et al. (1993), the continuum energy distribution of the star can be fitted by a power law of the form $F_{\lambda} \sim
\lambda^{-\alpha}$, where $\alpha = 2.59$, over the range $1500-9000~{\mbox \AA}$.

Dopita et al. (1994) noted that the fine ring nebula, $87'' \times 107''$in diameter, discovered by Chu & Lasker (1980), is embedded in a larger shell structure.

Acknowledgements

We gratefully acknowledge the helpful support, comments and criticism of K.A. van der Hucht, G. Meylan, A.F.J. Moffat, D.H. Morgan and N.R. Walborn. We also wish to thank A. Gemmo and O. Hainaut for their assistance in the measurements of the star coordinates. We appreciate the valuable suggestions of the referee, Virpi Niemela, regarding the presentation.


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