Central Bureau for Astronomical Telegrams
IAUC 2954: 1975n; Poss. IR COUNTERPART OF MXB1730-335; B2 1308+326
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 2955
Circular No. 2954
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
Western Union: RAPID SATELLITE CAMBMASS
COMET WEST (1975n)
The following precise positions have been reported:
1976 UT R. A. (1950) Decl. m1 Observer
Mar. 24.38576 20 58 39.19 +12 15 03.4 Eaton
31.03264 20 50 29.66 +13 23 51.6 Raudsaar
31.09097 20 50 25.54 +13 24 20.7 "
Apr. 2.05208 20 48 10.36 +13 43 19.9 "
8.04722 20 41 16.48 +14 38 06.0 "
9.06042 20 40 04.44 +14 47 03.6 "
24.71563 20 18 41.78 +16 48 22.6 6.8 Seki
24.72257 20 18 41.07 +16 48 26.5 "
May 5.70938 19 59 02.76 +17 47 10.1 "
9.74306 19 50 46.31 +18 00 22.8 8.2 "
10.45833 19 49 14.82 +18 02 07.1 Giclas
10.47118 19 49 12.96 +18 02 07.0 "
D. Eaton and A. Peaceman (Harvard University Science Center). 7.6-cm
f/7 astrograph. Essentially nucleus D.
H. K. Raudsaar (Tartu Observatory) Reduced at I.T.A., Leningrad.
Communicated by G. R. Kastel'. Essentially nucleus D.
T. Seki (Kochi Observatory, Geisei Station). From Orient. Astron.
Assoc. Comet Bull. Nos. 128 and 129. Nucleus A.
H. L. Giclas (Lowell Observatory). 33-cm photographic telescope.
Measurer: M. L. Kantz. Nucleus A.
Further photographic observations of the separations and position
angles of nuclei B and D (relative to nucleus A):
Nucleus B. May 7.00 UT, 45".1, 307o (R. Bendel, Traunstein, Germany);
9.43, 45".4, 300o (S. Murrell and C. Knuckles, New Mexico
State University; measured by E. J. Reese); 9.74, 47".2, 297o
(Seki); 10.46, 45".9, 300o (Giclas); 10.47, 45".8, 299o (Murrell).
Nucleus D. Apr. 24.72 UT, 16".2, 313o (Seki); May 5.71, 20".8, 308o
(Seki); 7.00, 19".4, 309o (Bendel); 9.43, 20".0, 308o (Murrell);
9.74, 20".9, 306o (Seki); 10.46, 21".7, 305o (Giclas); 10.47,
20".2, 307o (Murrell).
J. Bortle, Brooks Observatory, provides the following visual
magnitude estimates for the condensations (32-cm reflector): Apr.
30.29 UT, A = 13.3, B = 14.7, C = 14.2; May 4.29, 13.2, 14.8, 14.4;
13.32, 13.0, -, 13.3; 21.26, 13.4, (14.7), 13.3; 23.26, 14.2, 14.8,
14.3. Total magnitude estimates and tail information (10 x 50
binoculars): Apr. 30.29, 6.6, 1o.75 in p.a. 275o; May 4.29, 7.1, 2o in
267o-287o; 13.32, 7.1, 0o.7 in 285o; 23.26, 7.2, 0o.8 in 267o.
Ephemeris continuation from the elements on IAUC 2931:
1976 ET R. A. (1950) Decl. Delta r m1
July 1 17 52.16 +11 34.9 1.706 2.594 10.3
11 17 37.43 + 9 07.7
21 17 26.74 + 6 43.2 2.083 2.878 11.2
31 17 19.68 + 4 27.0
Aug. 10 17 15.77 + 2 22.3 2.550 3.149 12.0
20 17 14.46 + 0 29.9
30 17 15.29 - 1 10.4 3.073 3.409 12.8
Sept. 9 17 17.87 - 2 38.9
19 17 21.86 - 3 56.7 3.619 3.660 13.4
29 17 26.99 - 5 04.4
Oct. 9 17 33.02 - 6 02.7 4.156 3.904 14.0
19 17 39.77 - 6 52.2
29 17 47.07 - 7 33.7 4.661 4.141 14.5
Nov. 8 17 54.76 - 8 07.4
18 18 02.73 - 8 33.9 5.108 4.371 14.9
m1 = 5.0 + 5 log Delta + 10 log r
POSSIBLE INFRARED COUNTERPART OF MXB1730-335
W. Wamsteker, European Southern Observatory, reports that an
infrared source having K = +5.80 +/- 0.18, K-L = +0.36 +/- 0.02, K-M =
+0.58 +/- 0.5 has been found at R.A. = 17h30m08s +/- 0s.8, Decl. = -33o21'16"
+/- 10" (equinox 1950.0). The position (the uncertainty of which
represents the diaphragm size) is in excellent agreement with that of
the optical candidate reported by Liller (IAUC 2929, 2936).
B2 1308+326
B. and D. Wills, McDonald Observatory, write: "B2 1308+326 (cf.
IAUC 2939) was observed spectroscopically with the 270-cm reflector
on Mar. 25, Apr. 2 and 3. The spectrum appears continuous between
3300 and 7000 A (resolution 5-10 A), supporting the classification
as a BL-Lac object. The object was judged equal in brightness to
the star 134" to the west, 36" south; a visual observation on Apr.
27 suggested brightening by 0.25 magnitude. On overlapping Sky Survey
prints the object brightened by about 1 magnitude in 5 years."
D. Dickinson, Center for Astrophysics; C. R. Purton, York
University; P. A. Feldman, Herzberg Institute of Astrophysics; and
R. E. Goodson and A. H. Bridle, Queen's University, write:
"Measurements during Apr. 14-21 with the 46-m telescope of the Algonquin
Radio Observatory at a frequency of 22 GHz yielded a continuum flux
density of 3.3 +/- 0.1 Jy with no indication of variability. Comparison
with data at lower frequencies indicates the high-frequency excess
of radiation that is commonly associated with BL-Lac objects."
1976 May 24 (2954) Brian G. Marsden
Read IAUC 2955
Our Web policy. Index to the CBAT/MPC/ICQ pages.
