Circular No. 6457

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)

BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) Phone 617-495-7244/7440/7444 (for emergency use only)

COMET P/1996 N2 (ELST-PIZARRO) The orbital elements below, by the undersigned, are from 15 obser-

vations July 14–Aug. 21. Identity with the asteroidal object 1979 OW_{7}, observed at Siding Spring and Palomar on 1979 July 24 and 25 at mag 19.5, seems likely (with T = 1979 July 13.9).

T = 1996 Apr. 16.0159 TT  ω = 132.^{o}4528
e = 0.170415  Ω = 160.3483 }2000.0
q = 2.617717 AU  i = 1.3754
a = 3.155453 AU n^{o} = 0.1758375 P = 5.605 years
1996 TT α_{2000} δ_{2000} Δ r ϵ β m_{1}
Aug. 15 21^{h}40.^{m}78 −13^{o}11.^{′}7 1.657 2.670 179.^{o}1 0.^{o}3 17.4
20 21 37.03 −13 33.4 1.665 2.674 174.8  2.0 17.4
25 21 33.40 −13 54.4 1.680 2.679 169.0  4.1 17.4
30 21 30.02 −14 14.1 1.700 2.683 163.3  6.2 17.4
Sept. 4 21 26.98 −14 31.9 1.728 2.688 157.7  8.2 17.5
9 21 24.37 −14 47.5 1.761 2.693 152.2 10.1 17.5
14 21 22.26 −15 00.6 1.800 2.698 146.7 11.8 17.6
19 21 20.71 −15 10.9 1.844 2.703 141.5 13.4 17.6
24 21 19.76 −15 18.3 1.893 2.708 136.3 14.8 17.7
29 21 19.42 −15 22.8 1.946 2.714 131.3 16.1 17.8
Oct. 4 21 19.69 −15 24.3 2.003 2.719 126.4 17.2 17.9
9 21 20.56 −15 22.9 2.064 2.725 121.7 18.2 17.9
14 21 22.02 −15 18.6 2.128 2.731 117.1 19.0 18.0
19 21 24.05 −15 11.5 2.194 2.737 112.7 19.6 18.1
24 21 26.60 −15 01.6 2.262 2.743 108.3 20.1 18.2
29 21 29.65 −14 49.1 2.332 2.749 104.1 20.5 18.2
Nov. 3 21 33.16 −14 34.0 2.404 2.755 100.0 20.8 18.3
8 21 37.10 −14 16.5 2.476 2.761  96.0 20.9 18.4
13 21 41.42 −13 56.6 2.550 2.768  92.0 20.9 18.5

BL LACERTAE R. Nesci and E. Massaro, Istituto Astronomico, Universitá di Roma

“La Sapienza”, report that the emission lines observed last year in BL Lac by Vermeulen et al. (IAUC 6176) have disappeared. Observations were made on Aug. 7 with the 1.5-m telescope of the Loiano Observatory at 1.2-nm resolution; an upper limit of ∼ 0.1 nm can be established for the Hα line equivalent width, against the 0.7-nm observed width last year.

1996 August 21  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1996 CBAT  Brian G. Marsden