Blue continua with 
, 
and He I 5876 Å in emission.
.
in
emission but higher Balmer lines in deep, relatively narrow absorption onto
of a blue continuum. 
and, to a lesser extent, 
appear partially filled-in by an emission core. Ringwald found a fine
sinusoidal modulation of the 
radial velocity with an amplitude
of 
and a period of 7.6 hours. However he dismissed a CV classification
for PG 1002+506 and ascribed the RV modulation to some sort of noise
and/or uneven sampling of the data.
). With an observed 
the object
would lie at 
if an analogue of an Herbig Ae/Be
star, with an implausible large 
for a young object.
Alternatively, it could be a sdB-O star in a close binary or more probably
a CV seen nearly pole-on (in agreement with the sharpness of absorption
lines). The object deserves further investigation.
and V=15.5 the object must be a sdO.
emission. Comparing with the magnitude range quoted by DS93, our observation
at V=18.7 suggests the object was in between quiescence and outburst
states.
. This corresponds to an outburst state, as confirmed by the
bright V=13.6 magnitude (cf. Table 7 (click here)) compared with the range of
variability of the star listed by DS93. Adopting the intrinsic colors of a
B8 V star, the B-V in Table 7 (click here) suggests 
and the
gives 
.
.
The star could have been caught during an outburst.
) and two major outbursts in 1938 and 1975,
when the star rose to B=15.5 Since 1975, the star is at flat maximum. They
pointed out photometric similarity with symbiotic novae like PU Vul or HM
Sge. Our spectrum is that of a WD of type DA (or possibly that of a CV in
outburst, cf. the AM Cas spectrum in the same Fig. 1 (click here)), with no
evidence for emission cores in the broad Balmer absorptions. Object
classification is quite obscure given the photometric history. The spectrum
has no relation to those of symbiotic stars and symbiotic novae both in
quiescence and outbursts, and maximum brightness lasting 20 years makes
association with typical CVs very difficult. Enigmatic object deserving
further investigations.
emission on a reddish, featureless
continuum. Magnitudes and colors in Table 7 (click here) are very close to the
values measured by Misselt (1996). Classification uncertain.
against the variability range reported by DS93 as
14.5-17.2 in blue light. 
is in moderate emission, 
filled-in and 
in absorption. The spectrum resembles
outburst conditions. Magnitudes and colors index in Table 7 (click here) well
match those measured by Misselt (1996).
core in emission. Magnitude and colors from our spectrum are in
good agreement with the value reported by Bruch & Engels
(1994).
. We observed the object at 
, at the maximum of the brightness range listed by DS93. It could be a
CV caught during an outburst.
in emission, possible 
core in emission inside a
broad absorption, higher Balmer lines in absorption. Colors in
Table 7 (click here) suggest a 
.
ratio is still close to unity.
in 1857, 1858, 1904 and 1906, otherwise fainter than mag 10 or
12, a behaviour quite unusual for real novae. It could be a mis-identified
object on the D87 finding chart, or a dwarf nova with erratic outbursts
(and quiescence spectra dominated by the cool star) or a different type of
variable. Downes & Skody reported that a nearby star, of 
,
could have the 
in emission.
emission on a quite red continuum
without molecular bands. Classification uncertain.
emission.
Dwarf nova outbursts described by Romano & Minello (1976).
, 
, He I 6678
Å\
and possibly Balmer continuum appear in emission onto of a reddish
continuum. Major differences with the spectrum presented by Remillar
et al. (1994) are He II 4686 Å very weak or absent in our spectrum,
marked NaI D absorption and absence of He I 5876 Å.
Figure 1: Spectra of AM Cas (Asiago), V1504 Cyg and V410 Cas. The offset
applied for plot clarity is given in brackets next to the star name. The
spectra are not corrected for reddening. Fluxes in units of 
Figure 2: Spectra of CG Cep, V1075 Cyg and 1H 1933+510. The offset applied
for plot clarity is given in brackets next to the star name. The spectra
are not corrected for reddening. Fluxes in units of 
Figure 3: Spectra of V513 Cas, LM Cas and V1062 Tau. The offset applied
for plot clarity is given in brackets next to the star name. The spectra
are not corrected for reddening. Fluxes in units of 
Figure 4: Spectra of V811 Cyg, KW And and PV Per. The offset
applied for plot clarity is given in brackets next to the star name. The
asterisk means that a boxcar smoothing (with a window of 3 pixels) has been
applied. The spectra are not corrected for reddening. Fluxes in units of
Figure 5: Spectra of NQ Lac and MY Per. The offset applied for plot
clarity is given in brackets next to the star name. The asterisk means that
a boxcar smoothing (with a window of 3 pixels) has been applied. The
spectra are not corrected for reddening. Fluxes in units of 
Figure 6: Spectra of SY Gem #2 and HR Del. The (arb.) notation
means an arbitary zero point setting in the flux scale. The spectra are not
corrected for reddening. Fluxes in units of 
Figure 7: Spectra of V751 Cyg, AM Cas (Loiano) and PG 1002+506. The offset
applied for plot clarity is given in brackets next to the star name. The
spectra are not corrected for reddening. Fluxes in units of 
Figure 8: Spectra of 1H 1025+220, 1H 0928+500 and EY Cyg. The offset
applied for plot clarity is given in brackets next to the star name. The
asterisk means that a boxcar smoothing (with a window of 3 pixels) has been
applied. The spectra are not corrected for reddening. Fluxes in units of
Figure 9: Spectra of IR Lyr, PG 1146+228 and SY Gem #1. The offset
applied for plot clarity is given in brackets next to the star name. The
(arb.) notation means an arbitary zero point setting in the flux
scale. The asterisk means that a boxcar smoothing (with a window of 3
pixels) has been applied. The spectra are not corrected for reddening.
Fluxes in units of 
Figure 10: Spectra of V476 Cyg, V344 Ori, AQ Cmi and EG Cnc. The offset
applied for plot clarity is given in brackets next to the star name. The
(arb.) notation means an arbitary zero point setting in the flux
scale. The asterisk means that a boxcar smoothing (with a window of 3
pixels) has been applied. The spectra are not corrected for reddening.
Fluxes in units of 
Acknowledgements
We would like to thank R. Passuello to have assisted us in securing some of the Asiago spectra.