Central Bureau for Astronomical Telegrams
IAUC 3106: 1977 HA; 1977c; Cir X-1; X-RAY FLARE NEAR 4U 1755-33
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Read IAUC 3107
Circular No. 3106
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
1977 HA
The following precise positions have been reported:
1977 UT R. A. (1950) Decl. Observer
Apr. 20.19253 13 08 06.95 +34 59 12.1 McCrosky
22.20067 13 12 44.41 +34 40 51.9 Shao
May 21.16979 13 44 13.69 +28 25 30.4 Shelus
23.10208 13 45 47.02 +27 55 41.4 McCrosky
R. E. McCrosky and C.-Y. Shao (Harvard College Observatory, Agassiz
Station). 155-cm reflector. Measurers: J. H. Bulger and Shao.
P. J. Shelus (McDonald Observatory). 208-cm reflector. Measurer:
M. Dritschel.
The following improved orbital elements are by the undersigned.
The closest approach to the earth was 0.032 AU on Apr. 1.8 ET.
T = 1977 Feb. 13.3471 ET Epoch = 1977 Feb. 26.0 ET
Peri. = 290.4182 e = 0.503665
Node = 190.8990 1950.0 a = 1.599742 AU
Incl. = 23.0513 n = 0.4871123
q = 0.794008 AU P = 2.023 years
COMET LOVAS (1977c)
The following precise position has been measured by Shao from
an exposure by McCrosky with Harvard Observatory's 155-cm reflector:
1977 UT R. A. (1950) Decl.
Apr. 12.11495 9 58 11.68 +30 49 58.8
The following improved parabolic elements, by the undersigned,
are from 13 observations Feb. 17 to Apr. 12:
T = 1976 Oct. 31.6399 ET Peri. = 146.2287
Node = 337.5029 1950.0
q = 5.710432 AU Incl. = 64.4506
1977/78 ET R. A. (1950) Decl. Delta r m2
Oct. 24 11 01.41 + 5 46.7 6.907 6.255 18.7
Nov. 3 11 04.79 + 4 39.1
13 11 07.50 + 3 33.9 6.691 6.313 18.6
23 11 09.43 + 2 31.6
Dec. 3 11 10.48 + 1 32.5 6.431 6.374 18.6
13 11 10.57 + 0 37.1
23 11 09.62 - 0 14.1 6.159 6.438 18.5
Jan. 2 11 07.60 - 1 00.6
12 11 04.51 - 1 42.0 5.917 6.503 18.5
22 11 00.42 - 2 17.9
Feb. 1 10 55.44 - 2 48.1 5.747 6.571 18.5
11 10 49.77 - 3 12.7
21 10 43.66 - 3 31.9 5.685 6.641 18.5
Mar. 3 10 37.40 - 3 46.5
13 10 31.28 - 3 57.4 5.752 6.712 18.6
23 10 25.59 - 4 05.7
Apr. 2 10 20.58 - 4 12.6 5.946 6.786 18.7
12 10 16.40 - 4 19.5
22 10 13.19 - 4 27.5 6.242 6.861 18.8
May 2 10 10.99 - 4 37.5
12 10 09.79 -4 50.5 6.605 6.938 19.0
22 10 09.57 - 5 06.8
June 1 10 10.23 - 5 27.0 6.997 7.016 19.2
11 10 11.71 - 5 51.3
21 10 13.91 - 6 19.8 7.383 7.096 19.4
July 1 10 16.72 - 6 52.5
11 10 20.06 - 7 29.4 7.734 7.178 19.5
21 10 23.81 - 8 10.4
31 10 27.91 - 8 55.4 8.026 7.260 19.6
CIRCINUS X-1
L. J. Kaluzienski and S. S. Holt, Goddard Space Flight Center,
report that the Ariel 5 all-sky monitor recorded a transition in
the 16.6-day cycle of Cir X-1 on Sept. 5.126 +/- 0.046 UT, consistent
with the ephemeris on IAUC 3099. A rapid turn-on in this cycle occurred
on Aug. 28.00 +/- 0.08. The 3-6 keV flux during the half-day
prior to turn-off was measured at 1.37 +/- 0.15 times the Crab (with
a dip to 0.38 +/- 0.07 in the ~ 4 h immediately preceding turn-off).
I. S. Glass, South African Astronomical Observatory, reports
that there was a very rapid rise in the infrared brightness of the
Mayo et al. candidate (IAUC 2957, 3095) on Sept. 5.73 UT. The complete
lightcurve is sawtooth shaped.
X-RAY FLARE NEAR 4U 1755-33
Kaluzienski and Holt also report that the revised error box
for this flaring transient source (cf. IAUC 3099), l = 357o.8 +/- 1o.0,
b = 1o.7 +/- 1o.5, apparently excludes 4U 1755-33 as the source. Further
half-day averages of the 3-6 keV flux yield intensities of
0.38 +/- 0.09 times the Crab on Aug. 31, 0.60 +/- 0.08 on Sept. 3 and
0.65 +/- 0.11 on Sept. 5.
1977 September 13 (3106) Brian G. Marsden
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