THE ASTRONOMER Electronic Circular No 660 1992 August 16 17.35UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke,
Hants, RG22 4PP,England. Telephone/FAX(0256)471074 Int:+44256471074
Telex: 9312111261 Answerback: TA G JANET BOXES:
GMH at UK.AC.CAM.ASTRONOMY.STARLINK or GUYH at UK.AC.SUSSEX.CLUSTER
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(4015) 1979 VA = COMET WILSON-HARRINGTON (1949 III)
In the course of examining the Palomar Sky Survey for prediscovery
images of minor planets, E. Bowell, Lowell Observatory, identified
trails of the borderline Apollo object (4015) 1979 VA on the 12-min
blue and 45-min red plates of 1949 Nov. 19.1 UT. B. A. Skiff found
that, to a limiting surface brightness of B about 25 mag/square
arcsec, a very slightly fanned tail of length 2'.8 is clearly
visible on the blue print at p.a. 90 +/- 5 deg, the antisun
direction being at p.a. 76 deg. The peak apparent surface
brightness, near the trailed image of the nucleus, is about 23
mag/square arcsec. The red Sky Survey image shows a very faint tail
of maximum surface brightness 24 mag/square arcsec. The nuclear
magnitude is near 13.5-14.0 on both prints. R. M. West et al,
European Southern Observatory, report that photographic
enhancements of glass copies of the Sky Survey plates confirm that
the tail feature is definitely present and attached to the trails
over their full length and apparently does not extend beyond the
trail ends; there is a gap of 9 min between the two exposures.
Brian Marsden points out that the 1949 object was in fact P/Comet
Wilson-Harrington (1949g = 1949 III), discussed in a report by
L. E.Cunningham on IAUC 1250 as having been entirely asteroidal in
appearance on further Palomar Schmidt exposures through Nov. 25.
No cometary emission was noted during the well-observed 1979-80
apparition. Recent spectroscopy by S. J. Bus, Lowell Observatory,
using the Ohio State University CCD spectrograph at the 1.8-m
Perkins reflector, has again shown no cometary emission and
indicates the object to be neutral in color to within a few percent
per 100 nm over the range 400-640 nm, in agreement with UBV color
indices measured by A. W. Harris and R. L. Millis in 1979 (IAUC
3426; Harris and Young 1983, Icarus 54, 59).
IAUC 5585
E. Bowell, Lowell Observatory, reports: "CCD imaging at the 1.07-m
Hall reflector by M. W. Buie, Lowell Observatory, and H. Picken,
Grinnell College, gave B = 18.4 +/- 0.1, R = 17.7 +/- 0.1 near 1992
Aug. 8.5 UT, intrinsically more than 2 mag fainter than the 1949
discovery images and perhaps indicative of a B-R color index
slightly bluer than that of the sun. No coma was present to a
limit of about 22 mag/square arcsec in either B or R. Taken
together, the observations suggest that the object is a largely
inactive comet that undergoes occasional outburst. The object is
well placed for observation during the coming months, and if
cometary activity occurs at an orbital longitude similar to that in
1949, it is to be expected around the beginning of Oct. 1992."
Epoch = 1992 Aug. 6.0 TT
T = 1992 Aug. 21.7397 TT Peri. = 90.8705
e = 0.622794 Node = 271.0643 2000.0
q = 0.996389 AU Incl. = 2.7860
a = 2.641499 AU n = 0.2295771 P = 4.293 years
1992/93 R. A. (2000) Decl. Delta r Elong.Phase V
Aug. 16 4 32.48 +27 04.4 0.543 0.999 73.0 75.7 17.3
26 5 21.53 +27 49.5 0.592 0.998 71.7 74.0 17.4
Sept. 5 6 03.47 +27 36.6 0.642 1.015 72.1 70.9 17.5
15 6 38.91 +26 48.3 0.689 1.049 73.8 67.1 17.6
25 7 08.50 +25 40.9 0.728 1.097 76.9 62.9 17.7
Oct. 5 7 32.60 +24 26.0 0.757 1.157 81.1 58.6 17.8
15 7 51.47 +23 12.1 0.777 1.226 86.5 54.3 17.9
IAUC 5586
Guy M Hurst