Central Bureau for Astronomical Telegrams
IAUC 3319: WZ Sge; ROTATION PERIODS OF MINOR PLANETS; NOTICE TO CABLEGRAM SUBSCRIBERS
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Circular No. 3319
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758
WZ SAGITTAE
E. F. Guinan and G. P. McCook, Villanova University Observatory,
report that H-alpha wide- and narrow-band photometry reveals an
apparent change in the period of the system. A time of minimum
light of 1978 Dec. 15.996 UT (heliocentric) was determined. This
minimum occurs about ten minutes earlier than predicted using the
recent ephemeris of Robinson et al. (1978, Astrophys. J. 219, 168).
The change in period appears to have been abrupt and probably is
associated with the recent outburst. The apparent decrease in the
period could arise from a migration of the hot. emitting region on
the disk or from an actual change in the orbital period.
Further visual magnitude estimates: Jan. 3.57 UT, 11.6 (R.
Lynch, Providence, RI); 5.11, 11.6 (J. Morgan, Prescott, AZ); 9.07,
11.8 (Morgan). On IAUC 3318 the name of the Dec. 30.02 observer
should read L. Hiett.
ROTATION PERIODS OF MINOR PLANETS
H. J. Schober, Institut fur Astronomie, Universitat Graz,
reports that reduction of photoelectric observations at the European
Southern Observatory in 1977 suggests that the minor planets
(387) Aquitania and (776) Berbericia have rotation periods close to
24 hours and thus difficult to establish. Provisional values are
24h.0 (or 12h or 16h, possibly even 48h) and 23h.0 (or perhaps 15h.3),
respectively. The two objects are currently near opposition again.
NOTICE TO CABLEGRAM SUBSCRIBERS
We regret that it was not possible to provide very satisfactory
service to cablegram subscribers to the telegram service during
much of 1978. We are aware that in some instances as many as five
garbled versions of the same message were received. The system expected
cooperation from the Western Union Telegraph Company that
the Company was not able to provide, despite its claims. As of
early December we were able to make special arrangements directly
with Western Union International, and these seem to be working much
more satisfactorily. It is also possible now to send the messages
at the delayed-delivery rate (to countries where this applies) of
$6.00 per message, rather than $9.00 (and sometimes $11.00). Subscribers
with preferences in this matter should so inform us.
1979 January 16 (3319) Brian G. Marsden
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