Circular No. 5487 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN COMET TANAKA-MACHHOLZ (1992d) On Mar. 31 Don Machholz reported his discovery of a probable comet, the slight change detected during his 35-min visual observation indicating a daily motion of up to perhaps 1 deg. This suggested possible identity with a cometary object reported by Zenichi Tanaka to the Japanese National Astronomical Observatory, this report having been forwarded by S. Nakano to the Central Bureau on Mar. 27; confusion arose because Tanaka's 4-min exposure was said to indicate a daily motion of more than 4 deg (in p.a. 20 or 200 deg), although it now appears that Tanaka had first detected the comet visually 25 min earlier and that there was no obvious motion. A. Hale's Apr. 1 observation confirms the Machholz discovery, and a parabolic perihelion orbit fitted to the approximate Mar. 31 and Apr. 1 positions satisfies the Mar. 24 Tanaka position within 0.6 deg. 1992 UT R.A. (2000) Decl. m1 Observer Mar. 24.823 21 54.8 +12 55 10 Tanaka 31.505 22 09.5 +18 43 9.4 Machholz Apr. 1.473 22 11.4 +19 33 9.6 Hale Z. Tanaka (Yodoe, Tottori). 0.2-m reflector. Very faint, unmeasurable image on exposure in twilight. Coma diameter 2'. D. Machholz (Colfax, CA). 0.12-m refractor. Object diffuse with some condensation, no tail. Coma diameter 2'. A. Hale (Las Cruces, NM). 0.41-m reflector. Diffuse, somewhat condensed. NOVA CYGNI 1992 K. Kasturirangan, ISRO Satellite Centre, Bangalore, reports the following magnitudes and colors (with probable errors), obtained by B. N. Ashoka and K. R. N. Kutty using a 0.35-m reflector and photon- counting system: Mar. 7.99 UT, V = 5.90 +/- 0.02, B-V = +0.32 +/- 0.01, U-B = -0.41 +/- 0.01; 8.99, 6.08 +/- 0.01, +0.35 +/- 0.01, -0.40 +/- 0.03; 9.99, 6.37 +/- 0.01, +0.33 +/- 0.01, -0.32 +/- 0.03; 12.99, 6.18 +/- 0.01, +0.40 +/- 0.01, -0.37 +/- 0.02; 16.99, 6.50 +/- 0.01, +0.28 +/- 0.03, -0.40 +/- 0.02; 17.99, 6.53 +/- 0.01, +0.30 +/- 0.01, -0.40 +/- 0.01; 18.99, 6.73 +/- 0.01, +0.27 +/- 0.01, -0.42 +/- 0.02; 19.99, 6.84 +/- 0.02, +0.29 +/- 0.01, -0.43 +/- 0.01. HR 7876 and HR 7854 were used as comparison and check stars, respectively. 1992 April 1 (5487) Brian G. Marsden
Our Web policy. Index to the CBAT/MPC/ICQ pages.