Central Bureau for Astronomical Telegrams
IAUC 6420: C/1996 B2; ROSAT ALL-SKY SURVEY BRIGHT SOURCE CATALOGUE
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Circular No. 6420
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
Phone 617-495-7244/7440/7444 (for emergency use only)
COMET C/1996 B2 (HYAKUTAKE)
K. Jockers and G. Lichtenberg, Max Planck Institute for
Aeronomy, Katlenburg-Lindau, write: "From observations of this
comet obtained on Apr. 1.9 UT with the Hoher List 1-m reflector, we
derive a CO+/H2O+ ratio > 1 at a tailward distance of 6.4 x 10E4 km
from the nucleus. In comet 1P/Halley, this value was < 0.2 (Lutz
et al. 1993, Ap.J. 407, 402). This indicates that C/1996 B2 may be
rich in carbon compounds."
Visual m1 estimates: June 9.79 UT, 5.3 (D. Seargent, The
Entrance, N.S.W., Australia, naked eye); 11.80, 5.2 (P. Camilleri,
Cobram, Vic., Australia, 20x80 binoculars).
ROSAT ALL-SKY SURVEY BRIGHT SOURCE CATALOGUE
W. Voges, B. Aschenbach, T. Boller, H. Brauninger, U. Briel,
W. Burkert, K. Dennerl, J. Englhauser, R. Gruber, F. Haberl, G.
Hartner, G. Hasinger, M. Kurster, E. Pfeffermann, W. Pietsch, P.
Predehl, C. Rosso, J. H. M. M. Schmitt, J. Trumper, and H.-U.
Zimmermann, Max-Planck-Institut fur Extraterrestrische Physik,
Garching, report: "The ROSAT All-Sky Survey Bright Source Catalogue
(RASS-BSC, revision 1RXS) has been released and is available
through the World Wide Web (URL
http://www.rosat.mpe-garching.mpg.de/survey/rass-bsc/) and via
anonymous ftp (host ftp.rosat.mpe-garching.mpg.de, directory
archive/survey/rass-bsc). This catalogue is derived from the all-
sky survey performed during the first half year of the ROSAT
mission in 1990-1991; 18 811 sources are catalogued, with a
limiting ROSAT PSPC countrate of 0.05 cts/s in the energy band 0.1-
2.4 keV. The sources have a detection likelihood of at least 15
and contain at least 15 source photons. At a brightness limit of
0.1 cts/s (8547 sources) the catalogue represents a sky coverage of
92 percent. For each source are provided the ROSAT name, the
position in equatorial coordinates, the positional error, the
source countrate and error, the background countrate, exposure time,
hardness-ratios HR1 and HR2 and errors, extent and likelihood of
extent, and likelihood of detection. For 94 percent of the sources,
visual inspection confirmed the results of the standard processing
with respect to existence and position; the remaining 6 percent
were reanalyzed and appropriately flagged. Broadband images are
available for a subset of the flagged sources. A list containing
correlations with other catalogues and identifications will follow
soon. Questions or comments may be directed to
survey@rosat.mpe-garching.mpg.de."
(C) Copyright 1996 CBAT
1996 June 19 (6420) Daniel W. E. Green
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