Central Bureau for Astronomical Telegrams
IAUC 3665: COMETS HARTLEY (1982b, 1982c); 1982 BB
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Read IAUC 3666
Circular No. 3665
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-864-5758
COMETS HARTLEY (1982b, 1982c)
Further computations by the undersigned have included attempts
to represent the observations of comet 1982c with orbits fitted to
the observations of comet 1982b and a change in perihelion time T.
The best representation comes from the orbit with e = 0.59 (cf. IAUC
3664) and T changed to 1982 Apr. 1.888 ET; residuals are ~ l" on
Feb. 5 and 6 but almost 15" (mainly in Decl.) on Feb. 7. The resulting
ephemeris is Feb. 10, R.A. = 12h44m.3l, Decl. = - 9o00'.9; 15, 12h59m.72,
-11o26'.0; 20, 13h16m.29, -13o59'.6; 25, 13h34m.15, -16o40'.1; Mar. 2,
13h53m.38, -19o24'.6, with the comet brightening to m1 ~ 16.
Z. Sekanina, Jet Propulsion Laboratory, remarks that it is
virtually certain that the two comets separated from a single object
and that, unless there was a significant separation velocity in the
orbit plane at the time of splitting, the primary (i.e., most massive)
component must in fact be the currently fainter comet 1982c;
he anticipates that comet 1982b will fade rapidly. He confirms a
discordance in the observations of one of the comets on Feb. 7 and
suggests that separation occurred in late 1976. The orbit with e =
0.59 indicates that the relative separation acceleration was 7 (+/- 4)
x 10**-5 units of solar attraction, and the results seem to be
substantially less satisfactory if e is assumed to be greater than 0.63.
1982 BB
Precise positions obtained by J. Gibson at Palomar:
1982 UT R. A. (1950) Decl.
Feb. 2.38615 10 35 34.92 +20 54 10.6
3.30489 10 34 03.29 +21 33 22.0
3.50975 10 33 41.20 +21 42 00.8
Computations by the undersigned (using also the rough position
on IAUC 3660) show this to be an Apollo-type object (T = 1981 Sept.
24.1 ET, Peri. = 252o.7, Node = 130o.0, Incl. = 22o.5, q = 0.901 AU, e = 0.372).
1982 ET R. A. (1950) Decl. Delta r Mag.
Feb. 10 10 22.08 +26 02.4 0.561 1.533 15.9
15 10 12.69 +28 57.9
20 10 03.45 +31 26.9 0.616 1.581 16.2
25 9 54.81 +33 28.0
Mar. 2 9 47.18 +35 02.1 0.694 1.626 16.7
1982 February 11 (3665) Brian G. Marsden
Read IAUC 3666
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