Central Bureau for Astronomical Telegrams
IAUC 3452: 4U 1907+09; 1979l
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 3453
Circular No. 3452
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
4U 1907+09
N. Marshall and M. G. Watson, X-Ray Astronomy Group, Leicester
University, report that recent observations with the Ariel 5 ssi
have revealed a dramatic flare from 4U 1907+09. The source intensity
rose rapidly from ~ 0.02 Crab on Jan. 12 to reach a maximum of
~ 0.25 Crab on Jan. 25. The subsequent decay appears to have been
occurring on a timescale of ~ 1 month. Previous ssi observations
have not indicated similar behavior. 4U 1907+09 has recently been
identified with a 16-mag early-type star (R.A. = 19h07m15s.1, Decl. =
+9o44'53".5, equinox 1950.0) showing broad H-alpha emission (Schwartz et
al. 1980, A.J. in press). Optical observations, when they become
feasible, will be of particular interest.
M. Oda and the Hakucho X-Ray Astronomy Group communicate: "We
have detected an intense x-ray transient in Aquila. The error circle
of 1o radius is centered at R.A. = 19h07m, Decl. = +9o.5 and includes
4U 1907+09. We believe that this transient is 4U 1907+09, which
the Ariel-5 ssi observed to flare up recently. During our observations
(Jan. 26-30) the intensity in the 1-12-keV range remained
approximately constant at ~ 0.3 Crab."
COMET BRADFIELD (1979l)
L. W. Brown, A. D. Mallama and C. W. McCracken, Laboratory for
Astronomy and Solar Physics, Goddard Space Flight Center, report
that several spectrograms of comet 1979l have been obtained with
the Goddard 0.91-m telescope. A 20-min exposure (dispersion 22 x
10**-6) on Jan. 30.0 UT shows emission from CN, C2, C3 and possibly
CO+. A 45-min exposure on Feb. 5.0 UT shows emission from CN, C2,
C3, OH, NH and CH, but no CO+.
Selected visual observations: Jan. 15.31 UT, m1 = 5.5 (V. F.
de Assis Neto, Sao Francisco de Oliveira, 10 x 70 binoculars);
22.30, 4.6 (de Assis Neto); 29.98, 5.3, D = 13' (J. Bortle, Brooks
Observatory, 10 x 50 binoculars); 31.00, 5.5, 13' (Bortle); Feb.
1.04, 6.1, 3'.5 (C. Sherrod, North Little Rock, 7 x 50 binoculars);
1.75, 6.4, 15', tail 0o.3 long in p.a. 53o (5. Baroni, M. Cavagna, G.
Clerici and L. Pansecchi, Milan, 15 x 80 binoculars); 2.00, 5.9, 12'
(C. S. Morris, Prospect Hill Observatory, 20 x 80 binoculars); 3.01,
6.0, tail 5' long in p.a. 90o (Morris); 4.13, 6.2, 10' (M. J. Mayo,
Thousand Oaks, CA, 0.12-m refractor); 5.01, 6.9, 7'.6 (J. DeYoung,
Palmyra, VA, 7 x 50 binoculars); 6.04, 6.5, 6', tails 60' in p.a.
80o and 50' in p.a. 50o (Morris).
1980 February 8 (3452) Brian G. Marsden
Read IAUC 3453
Our Web policy. Index to the CBAT/MPC/ICQ pages.
