Central Bureau for Astronomical Telegrams
IAUC 3125: SMC X-2 AND SMC X-3; U Gem; 1977m; 1977g
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 3126
Circular No. 3125
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Cable Address: SATELLITES, NEWYORK Telex: 921428
Telephone: (617) 864-5758
SMC X-2 AND SMC X-3
F. Li, G. Jernigan and G. Clark, Massachusetts Institute of
Technology, report that SAS 3 has detected two new x-ray sources in
the Small Magellanic Cloud: 2S 0052-739 (SMC X-2), located at R.A. =
0h52m54s.5, Decl. = -73o56'58"; and 2S 0050-727 (SMC X-3), located at
R.A. = 0h52m21s.2, Decl. = -72o42'01" (equinox 1950.0; 90-percent-confidence
error radii 25"). Their average energy fluxes in the spectral
range 2-10 keV during the period of observation Oct. 11-16 were 1.6
and 1.1 x 10**-10 erg cm**-2 s**-1, respectively. The corresponding
luminosities at an assumed distance of 65 kpc are 8 and 6 x 10**37 erg
s**-1. The sources are probably variable since they were not detected
in previous observations. An immediate search for optical or
radio counterparts is therefore advisable.
U GEMINORUM
HEAO-1 experimenters G. Garmire, P. Charles, K. Mason, S.
Bowyer, G. Riegler, I. Tuohy, E. Boldt, S. Holt, R. Rothschild and
P. Serlemitsos report the discovery of intense ultrasoft x-ray emission
from U Gem. A flux of 10**-10 erg cm**-2 s**-1 in the 0.15-0.30-keV
energy band was observed on Oct. 20.393 UT with the low-energy detectors
on the HEAO-1 spacecraft; the source was not detected at
energies above 0.3 keV. Observations on Oct. 19.558 UT revealed no
flux down to 10**-11 erg cm**-2 s**-1. Preliminary spectral analysis
yields a temperature of less than 0.04 K and a column density of
less than 10**19 atoms cm**-2.
The optical outburst of U Gem was monitored by J. Morgan,
Prescott, Arizona. He provides the following visual magnitude estimates:
Oct. 14.50 UT, 14.6; 16.40, 14.1 18.51, 12.2; 19.50, 9.0;
20.51, 9.3; 21.49, 9.3; 22.52, 9.4; 23.51, 9.4; 24.50, 9.4.
COMET KOHLER (1977m)
The following precise positions have been reported:
1977 UT R. A. (1950) Decl. m1 Observer
Sept. 7.79997 15 29 23.45 +28 28 21.4 10.8 Mrkos
7.80459 15 29 23.98 +28 28 16.2 "
8.78822 15 31 13.79 +28 09 33.7 10.6 "
8.79279 15 31 14.29 +28 09 27.7 "
9.79397 15 33 08.31 +27 50 06.6 10.5 "
9.79987 15 33 09.13 +27 49 57.1 "
11.78293 15 37 03.27 +27 10 41.7 10.4 "
11.78761 15 37 03.84 +27 10 34.5 "
12.80156 15 39 07.53 +26 50 01.1 10.2 Vavrova
12.80868 15 39 08.42 +26 49 51.4 "
Oct. 1.8462 16 26 43.55 +19 06 33.6 8.5 Manning
4.8250 16 35 49.21 +17 37 12.1 8.0 "
6.41736 16 40 53.17 +16 47 03.4 Furuta
6.42014 16 40 53.53 +16 46 58.2 "
11.42813 16 57 45.43 +13 57 39.9 8.4 Seki
11.43576 16 57 46.78 +13 57 24.0 "
A. Mrkos and Vavrova (Klet Observatory). The times of the Sept.
7.79997 and 11.78761 observations have been corrected.
B.Manning (Stakenbridge, near Kidderminster, England). Measurer:
P. Birtwhistle. Tail ~ 10' long in p.a. 80o. lambda = +2o09'50", phi
= +52o24'45" (provisional). Communicated by G. M. Hurst.
T. Furuta (Kagiya, Aichi). Communicated by T. Seki.
T. Seki (Kochi Observatory, Geisei Station).
The following improved parabolic elements, by the undersigned,
are from 54 observations Sept. 6 to Oct. 11:
T = 1977 Nov. 10.5571 ET Peri. = 163.4787
Node = 181.8247 1950.0
q = 0.990579 AU Incl. = 48.7180
The corresponding ephemeris (distances are on IAUC 3112) is:
1977 ET R.A. (1950) Decl. 1977 ET R.A. (1950) Decl.
Oct. 29 18 08.88 + 1 27.4 Nov. 18 19 51.83 -16 06.9
Nov. 3 18 32.58 - 2 48.3 23 20 20.24 -20 11.4
8 18 57.75 - 7 15.1 28 20 49.10 -23 49.4
13 19 24.24 -11 44.7 Dec. 3 21 18.02 -26 55.1
Further total visual magnitude estimates: Oct. 16.05 UT, 7.4
(C. S. Morris, Nantucket, Massachusetts, 10 x 50 binoculars); 19.07,
7.1 (P. Maley, Houston, Texas, 7 x 35 binoculars); 21.99, 7.2 (J.
Bortle, Brooks Observatory, 10 x 50 binoculars); 23.99, 7.2 (5.
O'Meara, Harvard Obs., 8-cm refractor; 15' tail in p.a. 65o).
PERIODIC COMET ASHBROOK-JACKSON (1977g)
The following precise positions were obtained by P. Jekabsons
and M. P. Candy at the Perth Observatory, Bickley:
1977 UT R. A. (1950) Decl. Observer
May 26.61113 15 52 32.70 -35 56 15.2 Jekabsons
Sept.11.51354 15 51 44.66 -32 19 20.8 Candy
13.53264 15 53 55.62 -32 20 16.4 Jekabsons
1977 October 25 (3125) Brian G. Marsden
Read IAUC 3126
Our Web policy. Index to the CBAT/MPC/ICQ pages.
