Circular No. 6547

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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XTE J1709−267

R. M. Hjellming and M. P. Rupen, National Radio Astronomy Observatory, report the discovery of a candidate for the radio counterpart of the x-ray nova XTE J1709−267 (IAUC 6543). VLA observations on Jan. 25.62 UT were used to detect a radio source with flux densities of ∼ 104 and ∼ 111 mJy at 1.42 and 4.9 GHz, respectively, at a position of α = 17^{h}09^{m}09^{s}.23, δ = −26^{o}42′19′′.0 (equinox 2000.0, estimated error < 1′′). This was the only detected radio source in the RXTE error region, and the probability of a 4.9-GHz background source of this strength in the field is ∼ 0.002. They add that further observations are underway to search for the variability typical of x-ray novae.

COMET C/1995 O1 (HALE-BOPP) Extension to the ephemeris on IAUC 6507 (elements on MPC 28557):

1997 TT α_{2000} δ_{2000} Δ r ϵ β m_{1}
Feb. 11 20^{h}07.^{m}85 +20^{o}50.^{′}1 1.807 1.251 41.^{o}4 31.^{o}5  0.3
16 20 24.40 +23 57.3 1.711 1.196 43.0 34.3 −0.1
21 20 43.63 +27 22.0 1.620 1.144 44.3 37.1 −0.4
26 21 06.32 +31 01.2 1.535 1.095 45.3 40.0 −0.7
Mar. 3 21 33.42 +34 48.4 1.460 1.050 46.0 42.7 −1.0
8 22 05.97 +38 31.4 1.398 1.010 46.2 45.2 −1.2
13 22 44.77 +41 51.1 1.352 0.976 46.1 47.2 −1.5
18 23 29.71 +44 22.6 1.323 0.948 45.6 48.6 −1.6
23 0 19.05 +45 42.1 1.315 0.929 44.8 49.1 −1.7
28 1 09.30 +45 36.5 1.327 0.917 43.7 48.7 −1.8
Apr. 2 1 56.54 +44 10.4 1.359 0.914 42.3 47.4 −1.7
7 2 38.11 +41 42.9 1.406 0.920 40.7 45.2 −1.6
12 3 13.22 +38 38.1 1.468 0.935 39.0 42.5 −1.5
17 3 42.36 +35 16.3 1.540 0.957 37.2 39.4 −1.3
22 4 06.55 +31 51.7 1.619 0.987 35.3 36.0 −1.0
27 4 26.85 +28 32.7 1.702 1.023 33.3 32.7 −0.7
May 2 4 44.15 +25 23.3 1.787 1.065 31.4 29.5 −0.5
7 4 59.16 +22 25.2 1.873 1.111 29.4 26.5 −0.2
12 5 12.42 +19 38.4 1.958 1.161 27.6 23.8  0.1
17 5 24.31 +17 02.1 2.041 1.215 25.9 21.3  0.4
22 5 35.14 +14 35.2 2.121 1.271 24.4 19.2  0.7
27 5 45.12 +12 16.5 2.199 1.329 23.2 17.5  0.9
June 1 5 54.43 +10 04.8 2.272 1.388 22.3 16.1  1.2
1997 January 27  \begin{matrix}c \\ ◯ \end{matrix} Copyright 1997 CBAT  Brian G. Marsden