Circular No. 6671

Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION

Mailstop 18, 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)

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Phone 617-495-7244/7440/7444 (for emergency use only)

GRB 970508 A. I. Kopylov, Special Astrophysical Observatory, and his colleagues

(cf. IAUC 6663) write: “Further optical multicolor observations of Bond’s variable object (IAUC 6654) were obtained with 6-m telescope. Our preliminary reduction shows the following Johnson and Kron-Cousins magnitudes on May 22.00 UT: B > 22.3, V = 22.9 ± 0.5, R_{c} = 22.2 ± 0.15, I_{c} = 21.7 ± 0.3. The object has continued to fade; over 11 days, a power law with a slope of −1.1 is a good approximation of its brightness decay in the R band.”

SUPERNOVA 1997cn IN NGC 5490

Corrigenda. On IAUC 6667, line 7, for 1991, read 1996, On line 12, for km/s) in comparison to read km/s), comparable to

COMET C/1995 O1 (HALE-BOPP) Extension to ephemeris on IAUC 6547 (elements MPC 29568):

1997 TT α_{2000}  δ_{2000}  Δ  r  ϵ  β  m_{1}
June 1 5^{h}54.^{m}43 +10^{o}05.^{′}0 2.272 1.388 22.^{o}3 16.^{o}1 1.2
6 6 03.19 + 7 59.1 2.342 1.449 21.7 15.0 1.5
11 6 11.49 + 5 57.8 2.408 1.510 21.5 14.3 1.7
16 6 19.40 + 4 00.4 2.470 1.573 21.8 13.9 1.9
21 6 26.97 + 2 05.9 2.528 1.636 22.4 13.7 2.2
26 6 34.26 + 0 13.6 2.583 1.699 23.4 13.8 2.4
July 1 6 41.28 − 1 37.1 2.633 1.762 24.7 14.0 2.6
6 6 48.06 − 3 26.8 2.680 1.825 26.3 14.3 2.8
11 6 54.62 − 5 16.0 2.723 1.889 28.2 14.7 2.9
16 7 00.96 − 7 05.2 2.763 1.952 30.2 15.2 3.1
21 7 07.10 − 8 54.7 2.799 2.015 32.3 15.6 3.3
26 7 13.03 −10 44.8 2.832 2.078 34.6 16.1 3.4
31 7 18.76 −12 35.8 2.863 2.141 37.0 16.6 3.6
Aug. 5 7 24.28 −14 27.9 2.891 2.203 39.4 17.0 3.7
10 7 29.58 −16 21.4 2.916 2.266 41.9 17.4 3.9
15 7 34.66 −18 16.4 2.939 2.328 44.5 17.7 4.0
20 7 39.50 −20 12.9 2.961 2.389 47.1 18.1 4.1
1997 May 29  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1997 CBAT  Daniel W. E. Green