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- Circular No. 5409
- 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
-
-
- EDITORIAL NOTICE
- Following the recommendation of IAU Commission 20 and the
- announcement on IAUC 5278, we shall henceforth be using on these
- Circulars the 2000.0 equinox (more specifically, the mean equator and
- equinox of the FK5/J2000.0 system) for positional observations,
- orbital elements and ephemerides of comets and minor planets.
- The independent variable for the elements and ephemerides will in the
- future be denoted by TT (terrestrial time, or more specifically
- terrestrial dyamical time), which is essentially identical with ET
- (ephemeris time), a term that is now considered obsolete. At the
- present time TT-UT is approximately +58 seconds. Following numerous
- requests, we shall also include in the ephemerides columns giving
- the solar elongation and the phase angle, and all the information
- will be given for each ephemeris line. We repeat the earlier advice to
- the effect that positions of novae, supernovae, etc., will continue to
- be given in the 1950.0 (FK4/B1950.0) system. The 2000.0 system and
- numerous "user-friendly" improvements are also being introduced in the
- Computer Service.
-
-
- 1991 VH
- The following precise positions have been obtained by R. H.
- McNaught and D. I. Steel at Siding Spring:
-
- 1991 UT R.A. (2000) Decl.
- Nov. 25.50433 1 00 24.50 -56 34 36.3
- 25.54699 1 00 34.54 -56 32 34.8
- 27.51292 1 08 31.49 -54 59 27.0
- 27.52360 1 08 33.76 -54 58 55.6
- Dec. 20.55921 2 16 10.63 -34 31 32.1
- 20.56671 2 16 11.65 -34 31 06.0
- 21.58118 2 18 35.35 -33 33 39.9
- 21.59549 2 18 37.29 -33 32 49.7
-
- Orbital elements from 15 observations Nov. 9-Dec. 21:
-
- T = 1991 Sept. 22.5580 TT Peri. = 206.9816
- e = 0.144068 Node = 139.5040 2000.0
- q = 0.973019 AU Incl. = 13.9269
- a = 1.136795 AU n = 0.8131688 P = 1.212 years
-
-
- 1991 December 24 Brian G. Marsden