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IAUC 6155: AL Com; GRAVITATIONAL MICROLENSING EVENTS; N Aql 1995

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                                                  Circular No. 6155
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)
Phone 617-495-7244/7440/7444     TWX 710-320-6842 ASTROGRAM CAM
MARSDEN@CFA.HARVARD.EDU or GREEN@CFA.HARVARD.EDU (science)


AL COMAE BERENICES
     J. A. Mattei, AAVSO, reports that this cataclysmic variable is
in outburst for the first time since March 1975 (IAUC 2760).
Available visual magnitude estimates:  Apr. 3.804 UT, 15.7: (L.
Szentasko, Veresegyhaz, Hungary); 4.97, [13.7 (P. Schmeer,
Bischmisheim, Germany); 5.149, 14.9 (D. York, Abiquiu, NM); 5.600,
12.7 (T. Cragg, Coonabarabran, New South Wales); 5.799, 12.4
(Szentasko); 5.83, 12.2 (Schmeer).


GRAVITATIONAL MICROLENSING EVENTS
     The MACHO collaboration (A. Alcock, T. Axelrod, R. Allsman, D.
Bennett, K. Cook, K. Freeman, K. Griest, S. Marshall, B. Peterson,
M. Pratt, P. Quinn, D. Reynolds, A. Rodgers, C. Stubbs, and W.
Sutherland; Lawrence Livermore National Laboratory, Center for
Particle Astrophysics, and Mount Stromlo Observatory) reports the
discovery of likely gravitational microlensing events in progress
toward the galactic bulge:  "The stars in question and their
positions are as follows:  event 95-1, R.A. = 17h59m00s.6, Decl. =
-28o36'58" (equinox 2000.0); event 95-2, R.A. = 18h08m25s.2, Decl.
= -27o58'38".  Both stars were constant at magnitudes R = 17.9 and
V = 19.0 during 1993 and have brightened by 1.6 and 0.5 mag,
respectively, as of 1995 Apr. 4.  Microlensing fits to data
obtained with the Mt. Stromlo 1.27-m telescope indicate that event
95-1 may reach a high amplitude between Apr. 10 and 12 or reach its
peak at a more modest amplitude prior to Apr. 10.  Event 95-2
appears to be a longer-timescale event that may not get brighter
than its present brightness.  Accurate photometry near the peak of
event 95-1 may yield valuable information about the nature of the
microlensing object.  Finding charts and additional information
regarding the MACHO Alert System are available by anonymous ftp,
address darkstar.astro.washington.edu, in the directory macho/Alert;
this directory will be periodically updated with new information as
new microlensing events are discovered.  Potential observers are
requested to contact macho@astro.washington.edu and/or D. Bennett
at telephone 510-423-0656 (USA), to coordinate observations."


NOVA AQUILAE 1995
     Visual magnitude estimates (cf. IAUC 6146):  Mar. 9.23 UT, 9.7
(A. Pereira, Cabo da Roca, Portugal); 14.52, 10.4 (P. Collins,
Scottsdale, AZ); 23.50, 10.3 (Collins); Apr. 3.18, 10.4 (Pereira).


1995 April 5                   (6155)            Daniel W. E. Green

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