Central Bureau for Astronomical Telegrams
IAUC 5994: P/SCHWASSMANN-WACHMANN 1; 4U 0142+614 AND RX J0146.9+6121
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Circular No. 5994
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
PERIODIC COMET SCHWASSMANN-WACHMANN 1
E. Lellouch, Observatoire de Paris, Meudon (OPM); G. Paubert,
Institut de Radio Astronomie Millimetrique (IRAM); N. Biver, D.
Bockelee-Morvan, P. Colom, J. Crovisier, and L. Jorda, OPM; P.
Rocher, Bureau des Longitudes, Paris; and D. Despois, Observatoire
de Bordeaux, report: "We observed the CO J(2-1) line in
P/Schwassmann-Wachmann 1 at the IRAM 30-m telescope on May 10-11
with a 0.06-km/s spectral resolution. The line consisted of a very
sharp component (0.15 km/s wide) of 0.6 K in brightness temperature,
blueshifted by -0.5 km/s, superimposed on a component of about 0.1
K extending from -0.9 to +0.5 km/s. A contamination of the broader
feature by galactic CO emission gradients cannot be excluded at the
present time. The blueshift of the sharp peak is indicative of
outgassing from the illuminated side of the nucleus, but its value
is larger than expected from the sublimation of exposed CO ice.
The total line area was 0.19 +/- 0.02 K km sE-1, which agrees well
with the line area previously observed at the JCMT (IAUC 5929),
taking into account beam sizes and efficiencies. The corresponding
production rate was of the order of 2 x 10E28 molecules/s (or 10E28
when taking into account only the sharp component)."
4U 0142+614 AND RX J0146.9+6121
C. Hellier, Department of Astronomy, University of Texas at
Austin, communicates: "A 10 700-s ROSAT PSPC pointed observation on
1993 Feb. 12-13 confirms that 4U 0142+614 is the source of an 8-s
pulsation (cf. IAUC 5889). The heliocentric period is 8.6878 +/-
0.0001 s and the semi-amplitude 5 percent, close to values from the
1984 EXOSAT ME data. The mean count rate was 4.8 counts/s. The
PSPC also recorded RX J0146.9+6121 at a rate of 0.18 counts/s. It
has a strong pulsation of 60 percent semi-amplitude with a period
of 1413 +/- 8 s, confirming that this star (identified with the Be
star LSI +61o235) is the source of the pulsation previously
attributed to 4U 0142+614, as suggested by Mereghetti et al. (1993,
A.Ap. 278, L23). The period is significantly different from the
value of 1455 +/- 3 s in the 1984 EXOSAT data (White et al. 1987,
MNRAS 226, 645). This is the first time that the two periodicities
have been securely assigned to their correct stars. RX J0146.9+6121
is probably a Be/neutron-star binary with the slowest known neutron-
star rotation. The high Lx/Lopt of >10 for 4U 0142+614 suggests
that it is a low-mass x-ray binary."
1994 May 24 (5994) Daniel W. E. Green
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