Central Bureau for Astronomical Telegrams
IAUC 3193: 1978 CA AND 1978 DA; 1978a; 1978b; PERIODICITY IN 4U 1700-37; X-RAY BURST
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Read IAUC 3194
Circular No. 3193
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
1978 CA AND 1978 DA
J. Degewij, Lunar and Planetary Laboratory, reports that
photometry with the 154-cm reflector yielded for 1978 CA on Mar. 8.374
UT the values V = 14.61, B-V = +0.93, U-B = +0.50, and for 1978 DA
on Mar. 8.415 V = 14.00, B-V = +0.83, U-B = +0.42. Uncertainties
are +/- 0.02 magnitude in V, 0.03 in B-V, 0.05 in U-B. A full light
curve from observations on Mar. 8 and 9 yielded a rotation period
of 3h44m.9 +/- 0m.8 for 1978 CA, with amplitude 0.80 +/- 0.03 magnitude
in V and a mean V of 14.31 (on Mar. 8.27 UT). The rotation period
of 1978 DA appears to be ~ 8h, the amplitude in V ~ 0.5 magnitude.
In each case Delta(V-I) < 0.03 magnitude. He also communicates
radiometric observations by L. and M. Lebofsky with the 71-cm reflector,
giving geometric visual albedo pv = 0.06 +/- 0.01 and diameter 2.0 +/-
0.3 km for 1978 CA and pv = 0.15 +/- 0.03 and diameter 1.0 +/- 0.3 km
for 1978 DA. He adds that the combination of reddish color and low
albedo for 1978 CA is unique and remarks that narrow-band
spectrophotometry of this object is urgently needed.
COMET WEST (1978a)
The following precise positions have been reported:
1978 UT R. A. (1950) Decl. m1 Observer
Feb. 10.30475 14 30 05.43 -10 37 30.5 Schuster
12.28129 14 29 41.01 -10 22 19.7 "
Mar. 2.63472 14 23 29.32 - 7 42 58.7 15 Urata
2.64149 14 23 29.33 - 7 42 56.6 "
H.-E. Schuster (European Southern Observatory). Measurer: R. M.
West, who adds that the remarks about the spectrum (IAUC 3162)
should be eliminated. Quantitative measurements show that the
comet's spectrum is pure solar reflection.
T. Urata (JCPM Yakiimo Station). From Nihondaira Obs. Circ. No. 950.
PERIODIC COMET WILD 2 (1978b)
Further precise positions have been reported as follows:
1978 UT R. A. (1950) Decl. m1 Observer
Jan. 30.86825 5 16 53.79 +20 04 39.9 12.6 Mrkos
30.88486 5 16 53.44 +20 04 42.1 "
Feb. 1.73094 5 16 24.52 +20 09 07.9 12.5 "
1.73823 5 16 24.45 +20 09 08.3 "
2.8519 5 16 10.80 +20 11 55.3 12 Manning
3.61778 5 16 03.05 +20 13 54.1 13 Kurosaki
4.60020 5 15 55.87 +20 16 21.8 "
5.55832 5 15 51.36 +20 18 58.6 "
9.87708 5 16 00.24 +20 30 50.8 Clough
10.8309 5 16 08.81 +20 33 34.7 12 Manning
11.8583 5 16 20.60 +20 36 36.5 Arbour
11.8962 5 16 21.21 +20 36 44.5 "
12.76743 5 16 33.56 +20 39 17.2 12.5 Mrkos
12.77258 5 16 33.73 +20 39 17.7 "
13.8349 5 16 51.24 +20 42 29.6 Manning
27.46742 5 24 53.64 +21 26 23.4 12 Urata
27.47431 5 24 53.98 +21 26 25.6 "
Mar. 2.47986 5 27 41.46 +21 36 25.0 12 "
2.49196 5 27 42.14 +21 36 27.5 "
8.14931 5 33 54.43 +21 55 02.3 Giclas
A. Mrkos (Klet Observatory). 62.5-cm Maksutov telescope.
T. Kurosaki (Utsunomiya). From Yamamoto Circ. No. 1878.
H. Clough and R. H. McNaught (Macnairston Observatory). Measurer:
P. Birtwhistle. Communicated by G. Hurst. Improved coordinates:
Long. = +4o33'20", Lat. = +55o26'22", h = 106 m.
B. Manning (Stakenbridge). Extremely well condensed, suggestion of
tail in p.a. ~ 80o on Feb. 10. Measurer: Birtwhistle.
R. Arbour (Bishopstoke, near Eastleigh, England). Communicated by
Hurst. Measurer: Birtwhistle. Long. = +1o18'50".3, Lat. = +50o57'46".5.
T. Urata (JCPM Yakiimo Station). From Nihondaira Obs. Circ. No. 950.
H. L. Giclas (Lowell Observatory). Measurer: M. L. Kantz.
Total visual magnitude estimates by J. Bortle, Brooks Observatory
(32-cm reflector): Feb. 25.03 UT, 11.5; Mar. 7.07, 11.5.
PERIODICITY IN 4U 1700-37
T. Matilsky, Rutgers University, and J. Jessen, Massachusetts
Institute of Technology, report the detection of a 97 +/- 1.5 min
periodicity in 4U 1700-37. The data cover three days of pointed
SAS-3 observations in Mar. 1977, free of contamination from GX
349+2. The pulsed fraction is ~ 50 percent and persists throughout
the observations. Because of the close proximity of the observed
period to the satellite orbital period (94.5 min), confirmation by
other observers is particularly desirable. Changes in period could
be large, since the object is believed to be a neutron star.
X-RAY BURST
W. Lewin, Massachusetts Institute of Technology, informs us
that the single burst observed on Mar. 8d07h47m32s UT (IAUC 3190)
in fact came from a source located 0o.5 to 2o away from MXB1659-29.
1978 March 15 (3193) Brian G. Marsden
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