Circular No. 6225

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 C/1995 O1 (HALE-BOPP) J. Davies and T. Geballe, Joint Astronomy Centre, Hilo; D. Cruik-

shank, NASA Ames Research Center; T. Owen, Institute for Astronomy, University of Hawaii; and C. de Bergh, Observatoire de Paris, Meudon, report the detection with the U.K. Infrared Telescope during Sept. 4–9 UT of a shallow absorption feature centered at ∼ 2.04 μm in the spectrum of this comet. The feature has a width of 0.2 μm and a depth of ∼ 8 percent and is tentatively attributed to water ice. No other spectral features were detected in the wavelength range 1.0–2.5 μm. An upper limit of 10^{−16} W/m^{2} was determined (in an aperture of size 1′′.2×4′′.8, east-west by north-south) for the 3.3- to 3.5-μm cometary emission feature.

COMET C/1995 Q1 (BRADFIELD)

Ephemeris from orbital elements on MPC 25623:

1995TT α_{2000} δ_{2000} Δ r ϵ β m_{1}
Sept. 20 11^{h}12.^{m}31 +14^{o}30.^{′}1 1.562 0.656 15.^{o}8 24.^{o}6  7.1
25 11 11.34 +17 45.1 1.561 0.745  22.7 31.3  7.7
30 11 10.71 +20 55.0 1.547 0.836  29.5 36.1  8.2
Oct. 5 11 10.30 +24 05.2 1.522 0.928  36.2 39.6  8.6
10 11 09.98 +27 20.9 1.490 1.019  43.0 41.9  8.9
15 11 09.59 +30 46.5 1.451 1.110  49.8 43.3  9.3
20 11 08.93 +34 26.7 1.410 1.199  56.7 44.0  9.5
25 11 07.77 +38 25.3 1.366 1.287  63.8 43.9  9.8
30 11 05.75 +42 45.9 1.323 1.374  71.1 43.2 10.0
Nov. 4 11 02.37 +47 30.7 1.284 1.459  78.6 41.8 10.2
9 10 56.84 +52 40.2 1.250 1.542  86.2 39.9 10.4
14 10 47.80 +58 11.7 1.225 1.624  93.8 37.4 10.5
19 10 32.69 +63 57.9 1.210 1.705 101.3 34.6 10.7
24 10 06.32 +69 44.0 1.209 1.785 108.3 31.7 10.9
29 9 17.5 +75 00.8 1.224 1.864 114.5 28.8 11.1
Dec. 4 7 46.5 +78 47.8 1.255 1.941 119.5 26.2 11.4
9 5 36.8 +79 32.1 1.303 2.017 123.1 24.1 11.6
14 3 53.9 +77 10.4 1.367 2.093 124.9 22.7 11.9
19 2 57.5 +73 27.5 1.446 2.167 125.1 21.8 12.2
24 2 27.69 +69 31.5 1.538 2.240 123.8 21.4 12.4
29 2 11.30 +65 48.3 1.642 2.313 121.4 21.3 12.7

1995 September 11 Daniel W. E. Green