------------------------------------------------------------------- THE ASTRONOMER Electronic Circular No 3103 2015 Aug 26 20.12UT Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke, Hants, RG22 4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK Backup: gmh@wdcc1.bnsc.rl.ac.uk WORLD WIDE WEB http://www.theastronomer.org ------------------------------------------------------------------- POTENTIAL METEOR SHOWER FROM COMET C/2015 D4 (BORISOV) P. Jenniskens, SETI Institute and Ames Research Center, NASA and others report that long-period comet C/2015 D4 (cf. CBET 4071; P around 560 years) has no known associated annual meteor shower but may be responsible for periodic meteor outbursts from its 1-revolution dust trail veering into the earth's path when the earth passes by the ascending node. While approaching the sun, the comet passes the ecliptic plane just outside of Jupiter's orbit, which results in strong periodic perturbations of the trail position near the earth's orbit. When the dust trail is in the earth's path at the right time, meteors are expected to radiate for about one hour from geocentric R.A. = 79 deg, Decl. = -32 deg, with geocentric velocity 45.9 km/s. The position of the 1-revolution dust trail was calculated between 1990 and 2050 AD and, based on the comet orbit calculated from 32 observations between 2015 Feb. 23 and Apr. 10 (cf. MPEC 2015-H37), meteor showers are expected in 2017 and 2029. However, a better comet orbit is required to make reliable predictions. Observers are encouraged to submit astrometric data for this comet. CBET 4127 issued July 30 SUPERNOVA 2015O (LOSS) 2015O Jun 22.37 18 13 49.23 +13 14 15.9 18.3 5.0"E 6.0"S A finding chart is viewable at: http://tinyurl.com/nrdnsd2 G. Hosseinzadeh et. al., Las Cumbres Observatory Global Telescope Network report that a spectrogram on June 27.54 UT with the FLOYDS robotic spectrograph on the 2-m "Faulkes Telescope North" at Haleakala Observatory in Hawaii, shows it to be a type-II supernova. CBET 4125 issued July 29 SUPERNOVA 2015P IN MCG -02-33-20 (PARKER) 2015P Jun 7.38 12 50 30.72 -10 52 40.5 18.2r 19 "E 84 "S The variable can be viewed at: http://tinyurl.com/o7fsfv6 N. Morrell and B. Shappee, Carnegie Observatories, report that optical spectroscopy on June 21 UT with the du Pont 2.5-m telescope at Las Campanas Observatory, reveal that it is a type-II supernova. SN 2015P is rather evolved, with good matches with type II-P supernovae at 4-6 weeks past maximum, with a best match to SN 2004et at +47 days. CBET 4126 issued July 29 Guy M Hurst