Central Bureau for Astronomical Telegrams

Central Bureau for Astronomical Telegrams -- Image credits

IAUC 4826: V745 Sco; V1521 Cyg (CYGNUS X-3); NOTICE TO SUBSCRIBERS

The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).


Read IAUC 4825  SEARCH Read IAUC 4827
IAUC number


                                                  Circular No. 4826
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 or GREEN@CFA.BITNET    MARSDEN or GREEN@CFAPS2.SPAN


V745 SCORPII
     S. Shore, Computer Sciences Corporation; G. Sonneborn, Laboratory
for Astronomy and Solar Physics, Goddard Space Flight Center; and S.
Starrfield, Institute of Geophysics and Planetary Physics, Los Alamos
National Laboratory, report: "Low-dispersion ultraviolet spectra (range
115-335 nm, resolution 0.6 nm) of the recurrent nova V745 Sco were
obtained with the International Ultraviolet Explorer satellite on Aug.
3.2-3.35 and 4.55-4.7 UT.  The ultraviolet spectrum is dominated by
high-temperature emission lines.  A weak continuum is also present
longward of 250 nm.  Visual magnitude estimates were derived from IUE
Fine-Error Sensor data (400-700 nm): Aug. 3.3 UT, 10.9; 4.7, 11.5.
There was no discernible change in the spectrum between the two
observing sessions, even though the optical brightness decreased by
about 0.6 mag.  The detected emission lines are: N V 124.0 nm, Si IV
140.0, N IV] 148.6, C IV 155.0, He II 164.0, O III] 166.6, N III]
175.0, C III] 190.9 blended with Si III] 189.2, Mg II 280.0, O III 313
and [Ne III] 335 nm.  C IV, N III] and Mg II, the strongest lines in
the spectrum, are extremely broad with FWHM about 4000 km/s.  Similar
lines and blends can be seen in the ultraviolet spectrum of the
recurrent nova U Sco obtained on 1979 June 28 near maximum (Williams et
al. 1981, Ap.J. 251, 221)."
     Magnitude estimates by W. Liller, Vina del Mar, Chile (2415 film,
minus UV filter): Aug. 1.03 UT, 9.9; 2.97, 10.2; 4.04, 10.4; 5.01, 10.7.


V1521 CYGNI (CYGNUS X-3)
     V. Kotov, Crimean Astrophysical Observatory, reports that the
recent flare (cf. IAUC 4817) was independently detected by N. S.
Nesterov, who found the 8.2-mm flux to increase from < 0.5 Jy on
July 19 to 11.32 +/- 0.1 Jy on July 21.


NOTICE TO SUBSCRIBERS
     Subscribers who wish to pay their bills to the Central Bureau
by bank wire transfer may now do so.  However, in order to ensure
that payments are properly credited to us by the Smithsonian
Institution, it is essential that such subscribers inform the
Central Bureau directly whenever these payments are made.  For
further details on how to make the bank transfers, please contact
the Central Bureau at the postal, TWX or e-mail addresses given at
the top of this Circular.


1989 August 5                  (4826)              Brian G. Marsden

Read IAUC 4825  SEARCH Read IAUC 4827


Our Web policy. Index to the CBAT/MPC/ICQ pages.


Valid HTML 4.01!