Comet 17P/Holmes
Abstract
M. Drahus and L. Paganini, Max-Planck-Institut fuer Sonnensystemforschung; and L. Ziurys and W. Peters, Arizona Radio Observatory (ARO), communicate their further monitoring of comet 17P at millimeter wavelengths (cf. IAUCs 8891, 8914) with the ARO 10-m Heinrich-Hertz Submillimeter Telescope on Mount Graham. Late evolution of the outburst was traced through the HCN(3-2) transition. The following integral sums of the antenna temperature were obtained, given in units of K km/s: 2007 Nov. 29.20-29.24 UT, 0.08 +/- 0.05; Dec. 5.13-5.36, 0.03 +/- 0.01; Dec. 28.13-28.31, < 0.06 (3-sigma upper limit). Note that these values were not corrected for the main-beam efficiency. The profiles of the spectral line suggest lower gas-expansion velocity than in October (cf. IAUC 8914), probably about 0.5 km/s. Under several assumptions, the following production rates were calculated, given as log Q(HCN): 2007 Nov. 29.20-29.24, 25.4; Dec. 5.13-5.36, 25.0; Dec. 28.13-28.31, < 25.4. The half-power radius of the beam was 14.5 arcsec.
- Publication:
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Central Bureau Electronic Telegrams
- Pub Date:
- March 2008
- Bibcode:
- 2008CBET.1289....1D