All the sources were primarily checked against the Catalog of Infrared
Observations (Gezari et al. 1994) for previous IR
published fluxes. Further searches were made in the SIMBAD data
base. Of the 30 sources presented here only 6 have previous reported
IR measurements - GRO 
, 
, 
, 
, 
and 
(see individual comments below for references on these objects).
- this source appears in the Bruhweiler et
al. (1987) paper on new Einstein detections (identified as Source 3)
and also in the ROSAT review of X-ray binary sources in the Small
Magellanic Cloud (Kahabka & Pietsch 1996). The IR flux and
colours presented here are consistent with it being a Be star in the SMC.
- this star was originally proposed as a
probable Be counterpart to an X-ray binary by Hughes (1994)
and confirmed by the optical spectroscopy of Southwell & Charles
(1996). These first IR measurements confirm this identification.
- reported by Kahabka & Pietsch
(1996) as possible high mass X-ray binary system. The IR results
reported here are just at the limit of the telescope, but consistent with an
SMC Be/X-ray binary system.
- these three sources are all
well-established HMXRBs in the Small Magellanic Cloud. None of them
have previously reported IR measurements and, as a group, they permit
us to establish the IR charactersitics of such systems in such a
location. This is particularily important when trying to identify new
systems - see the two RXJ sources discussed below.
- This object was originally proposed by
Bruhweiler et al. (1987) from Einstein observations as an SMC
source exhibiting a hard X-ray spectrum. Hence it was suggested as a
possible Be/X-ray binary system. Subsequently a serendipitous ROSAT source,
, was identified (Angelini, private communication) at a
position coincident with the original Einstein position. Follow up optical
and IR observations were carried out as part of this work and the IR
counterpart identified. The J-K colours reported here are similar to those
reported in Table 1 (click here) for three other established SMC sources (SMC 
and SMC 
) and hence support the identification of this
object as being similar to them. Follow up optical spectroscopy will help
identify this object better.
- This is one of two new Be/X-ray binary systems
identified by Hughes & Smith (1994) on the basis of ROSAT
observations and H alpha imaging. These first IR observations confirm
the detection of an IR flux but can say little more at the moment. The
source at J=14.9 is at the limit of the telescope. Using the V band
measurement of Hughes & Smith we can determine 
, similar
to that of SMC 
.
and 
- these sources are
also known as CAL 9 and CAL E, respectively (Long et al.
1981). Both re-occured in the ROSAT survey of the Large Magellanic
Cloud carried out by Schmidtke et al. (1994).
- Reported here are the first IR observations
of this proposed Be/X-ray binary system. Originally reported by Pakull
et al. (1985) it was subsequently detected by ROSAT (Haberl
et al. 1995a) from which pulsations at 13.7 s were reported
(Dennerl et al. 1995).
- Recently discovered from ROSAT data (Haberl
et al. 1995b), this system could either be a supergiant or Be star
binary. The one set of IR data presented here give no indication of
the degree of variability and hence no clues to help resolve this
ambiguity. A discussion of the properties of this source based upon
optical spectra will be presented elsewhere (Coe et al. in preparation).
- This X-ray system was originally identified with
another star in the region (Star 1 in the chart of Johnston et al.
1979) by van der Klis et al. (1983). The main basis
for their identification was the photometric variability of the
candidate. However that star exhibits no significant IR emission,
unlike Star 22 reported here. Star 1 and Star 22 lie only 
apart in a crowded region and it is possible that they both fell
within the 9'' aperture of the photometer used by van der Klis et
al. Again, follow up optical spectroscopy should confirm this
identification.
and 
- Both of these HEAO-1 sources
have been linked to a bright Be star in the X-ray error box (Tuohy
1988). The results presented here represent the first IR
measurements of these two stars and the strong IR signal confirms their Be
nature. Their association with the X-ray sources remains unconfirmed
until a more accurate X-ray position is obtained, or correlated IR and
X-ray variability is reported.
- this object was identified recently by Coe et
al. (1994a) as the correct optical counterpart to a new hard X-ray
transient discovered by CGRO (Stollberg et al. 1993). The new
IR measurements reported here demonstrate a long-term decline in the
emission from the circumstellar disk from a high of K=9.94 at the time
of the X-ray outburst.
- this is the optical counterpart suggested by
Caraveo et al. (1989) as the second fastest known
pulsar (61 ms) in an X-ray emitting binary system. Those authors
identified the object as an O5 type star, whereas Mereghetti et
al. (1994) suggest a Wolf-Rayet interpretation and could find no
evidence for the 61ms pulsations. Certainly these first IR
observations show a strong IR excess 
and
consistent with the presence of a significant stellar
wind or disk.
- this object is the counterpart to the X-ray
transient system discovered in 1975. It has only shown two major episodes of
X-ray activity since its discovery, the second occuring in January
1992 (Coe et al. 1994b) at which time its IR signal was
determined to be J=9.62 and (J-K)=1.03. Surprisingly, nearly 4 years
later its IR signal remained virtually unchanged even though the X-ray
emission has fallen below any detectable level. No other IR observations
exist in the literature so it is hard to tell what the "quiescent'' level
is for this system.
and 2S 
- these two systems have
very similar neutron star pulse periods (292 s and 297 s) and are located
only 15' apart. Their IR behaviour, however, over the period of our
observations is very different. 1E 1145.1-6141 (a supergiant system
first measured in the IR by Ilovaisky et al. 1982) has shown
no evidence of any variability. Whereas 2S 1145-619 (a Be/X-ray binary
first detected by Glass 1979) has varied by over 0.5 magnitude
in all the IR bands. Its long-term optical and IR behaviour and their
relationship to its X-ray outbursts will be presented elsewhere
(Stevens et al. 1997).
- this system has been proposed as a hypergiant,
rather than a supergiant (Kaper et al. 1995). The IR data
presented here certainly confirm the existence of strong IR excess and
the lack of variability is consistent with either a hypergiant or
supergiant system (as opposed to a Be star). Further work is needed to
resolve the hypergiant proposition.
and 
- Both of these HEAO-1 sources
have also been linked to a bright Be star in the X-ray error box (Tuohy
1988). As in the case of the previous two sources discussed above
(
and 
), our results represent the first IR
measurements of these two sources and the strong IR signal confirms
their Be nature.
- this is system is unusual in this sample in that
it contains a M6III giant in a
sybiotic system. The first IR measurements of this source were
presented by Glass & Feast (1973). The data presented here
indicate significant, but not very large, variations in the IR flux.
- this is the counterpart identified by Coe et al.
(1996) to the ASCA hard X-ray transient reported by Yamauchi et al.
(1995). The IR data reveal a steady long-term decline from J=9.64
to J=10.17 over the period July 1995 to October 1996. This is consistent
with the source being the correct identification for an X-ray object
having recently undergone an outburst.