Comets C/2008 D1, C/2008 D2, C/2008 D3, C/2008 D4 (Stereo)
Abstract
K. Battams and K. Baldwin have reported measurements, reduced and analyzed by B. G. Marsden, for four Kreutz-sungrazing comets found on images obtained with NASA's new "Solar-Terrestrial Relations Observatory" (STEREO), which involves two satellites ultimately to be located 45 deg ahead (STEREO-A) and 45 deg behind (STEREO-B) the earth in its orbit. The SECCHI suite of instruments on each satellite contains two coronagraphs ('COR2' having bandpass 650-750 nm and resolution 15"/pixel) and a "Heliospheric Imager" consisting of two telescopes ('HI1' having bandpass 650-750 nm and resolution 35"/pixel). The tabulated "discovery" observations below are given in the same format as used for the SOHO comets (see above); the 'C' under instrumentation denotes the 'COR2' instrument on both STEREO-A and -B, while the 'HI' flag denotes the 'HI1-A' instrument only. C/2008 D1, C/2008 D2, and C/2008 D4 were very faint (mag about 10-11 for the first and third objects, and about 9 for the second) and diffuse. C/2008 D3 was of mag perhaps 7 with a thin, faint tail in HI1-A images, and brighter (mag perhaps 3) with a thin tail in COR2 images; this is the first near-sun comet to have an orbit determined (cf. MPEC 2008-E58) using astrometry from two well-separated spacecraft (now 0.76 AU apart). Comet 2008 UT R.A.(2000)Decl. Inst. F MPEC C/2008 D1 Feb. 16.822 23 43.4 - 5 01 HI AW 2008-E58 C/2008 D2 19.461 23 55.6 - 4 05 HI AW 2008-E58 C/2008 D3 20.294 0 14.0 - 4 49 HI/C AW 2008-E58 C/2008 D4 20.933 23 58.9 - 3 23 HI RK 2008-E58
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- March 2008
- Bibcode:
- 2008IAUC.8926....2B