Central Bureau for Astronomical Telegrams
IAUC 3335: 2A 0311-227; AN UMa; Z And
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Read IAUC 3336
Circular No. 3335
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
2A 0311-227
Infrared observations of this x-ray emitting, AM Her-like star
(IAUC 3326) were made with the Anglo-Australian Telescope by M. J.
Ward, Institute of Astronomy, Cambridge; and D. A. Allen, M. G.
Smith and A. E. Wright, Anglo-Australian Observatory. Flickering
of +/- 0.2 magnitude was seen at J, H, and K, as in AM Her (Jameson
et al. 1978, Nature 271, 334). Relative to the quiescent level, a
minimum 0.8 magnitude deep was seen every 81.0 +/- 0.1 min (cf. IAUC
3324), followed within ~ 5 min by flaring up to 0.8 magnitude. The
epoch of the best observed minimum was 1979 Mar. 12d10h55m +/- 1m UT.
Similar variations were seen in the visible on the TV monitor. The
continuum was much bluer than that of AM Her, with J-K ~ +0.2.
AN URSAE MAJORIS
J. Liebert, University of Arizona; H. E. Bond, Louisiana State
University; and A. D. Grauer, University of Arkansas, communicate:
"The magnetic binary system AN UMa is currently in a state of
steady low luminosity. Spectrophotometry with the Steward Observatory
229-cm Reticon system showed that the normally strong H, He I,
and He II emission lines were absent throughout 90 percent of the
system's 1.9-hr orbital period on Feb. 27. Simultaneous photometry
with a 91-cm telescope at Kitt Peak National Observatory showed AN
UMa at B ~ 18.9, without conspicuous light variations. VV Pup has
been known to show a similar phenomenon, but this is the first time
AN UMa has undergone such an event. To our knowledge, the other AM
Her-type systems, and other cataclysmic variables, have never shown
such behavior."
Z ANDROMEDAE
G. Baratta, Rome Observatory; A. Altamore, Rome University; A.
Cassatella, European Space Agency, Madrid; and A. Giangrande, O.
Ricciardi and R. Viotti, Laboratorio di Astrofisica Spaziale,
Frascati, report that new ultraviolet spectra of Z And obtained
with the International Ultraviolet Explorer on Feb. 17 showed no
significant change in the emission lines. The minimum electron
density in the emitting region was 10**9 cm**-3. The optical spectrum,
obtained at Campo Imperatore, and the luminosity are still those of
the quiescent phase.
1979 March 14 (3335) Daniel W. E. Green
Read IAUC 3336
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