Central Bureau for Astronomical Telegrams
IAUC 2874: SN IN NGC 2487; FMO WEST; 1975p
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Read IAUC 2875
Circular No. 2874
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
SUPERNOVA IN NGC 2487
C. Kowal, Hale Observatories, reports the discovery, with the
46-cm Schmidt telescope at Palomar, of a supernova in NGC 2487 (R.A. =
7h55m.3, Decl. = +25o16', equinox 1950.0), 27" east and 16" north of the
nucleus. The photographic magnitude was 14.5 on Nov. 30 UT, and
the discovery was confirmed on Dec. 2.
A. Boksenberg, L. Searle and R. Kirshner report that a spectral
scan on Dec. 2 with the Palomar 508-cm telescope (using the
University College, London, image photon counting system) showed
the supernova to be of type I and near maximum light. The radial
velocity of NGC 2487 was measured to be approximately 4350 km s**-1;
combination of the corresponding distance (using a Hubble constant
of 55 km s**-1 Mpc**-1) and the magnitude of 14.5 gives an absolute
magnitude of -20.0, consistent with a type I supernova near maximum.
FAST-MOVING OBJECT WEST
R. M. West, European Southern Observatory, Geneva, reports the
discovery of a bright, long asteroidal trail on a 60-min exposure
with the 100-cm Schmidt telescope at La Silla, as follows:
1975 UT R. A. (1950) Decl.
Oct. 2.1756 0 57 50.10 -33 53 48.7
2.2173 0 57 35.41 -33 59 03.6
It is possible that the two positions should be interchanged.
COMET BRADFIELD (1975p)
The following precise positions have been reported:
1975 UT R. A. (1950) Decl. m2 Observer
Nov. 14.53507 11 15 18.23 -40 04 21.1 Giclas
14.63238 11 16 00.23 -40 09 13.4 13 Austin
19.71493 11 58 41.68 -44 21 29.2 Herald
21.06111 12 11 54.34 -45 21 25.4 Hers
21.07083 12 11 59.81 -45 21 47.2 "
24.05208 12 44 15.99 -47 15 57.2 "
H. L. Giclas (Lowell Observatory). 33-cm photographic telescope.
Measurer: M. L. Kantz.
R. R. D. Austin (Mount John University Observatory). 25-cm f/7
refractor. Measurer: P. M. Kilmartin.
D. Herald (Kambah, near Canberra). 31-cm reflector.
J. Hers (Randburg, near Johannesburg). 20-cm Celestron telescope.
The following improved parabolic elements, by the undersigned,
are from 13 observations Nov. 13 to 24:
T = 1975 Dec. 21.178 ET Peri. = 358.108
Node = 270.611 1950.0
q = 0.21863 AU Incl. = 70.626
1975/76 ET R. A. (1950) Decl. Delta r Elong. m1
Dec. 6 15 20.50 -47 07.8 1.069 0.540 30.1 5.5
8 15 45.95 -45 32.3
10 16 09.90 -43 29.5 1.096 0.437 23.4 4.6
12 16 32.16 -41 00.1
14 16 52.69 -38 04.1 1.138 0.334 16.1 3.5
16 17 11.57 -34 40.6
18 17 28.98 -30 48.0 1.184 0.247 7.7 2.3
20 17 45.04 -26 27.9
22 17 59.86 -21 50.9 1.202 0.221 1.8 1.8
24 18 13.54 -17 15.4
26 18 26.37 -12 54.2 1.174 0.279 10.9 2.8
28 18 38.68 - 8 49.6
30 18 50.77 - 4 59.1 1.132 0.376 18.8 4.0
Jan. 1 19 02.82 - 1 19.7
3 19 14.95 + 2 10.8 1.097 0.479 25.9 5.0
5 19 27.25 + 5 33.6
7 19 39.74 + 8 49.2 1.078 0.582 32.4 5.8
9 19 52.45 +11 57.5
11 20 05.40 +14 58.2 1.074 0.681 38.3 6.5
13 20 18.55 +17 50.7
15 20 31.91 +20 34.3 1.086 0.776 43.7 7.1
m1 = 8.0 + 5 log Delta + 10 log r
Z. Sekanina, Center for Astrophysics, Harvard and Smithsonian
Observatories, communicates: "The earth will be crossing the orbit
plane of the comet on Dec. 23.4 UT, and the projection conditions
will then be favorable for the appearance of an antitail of dust
particles (in p.a. 198o). However, only infrared methods could be
used to detect the feature, because the comet will be only 5o from
the sun. Even negative observations would be valuable, as they
would indicate the absence of detectable output of dust from the
comet prior to perihelion. Fairly favorable observing conditions
will persist for several weeks after the date of crossing. If
bright enough to detect, the antitail should be observed in p.a.
200o-215o at the beginning of January, rotating slowly counterclockwise
to p.a. ~ 230o-260o by the end. Owing to emissions near perihelion,
the sector of sky to the west of the comet might appear
brighter than that to the east, especially on long-exposure plates."
1975 December 3 (2874) Brian G. Marsden
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