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Gary Poyner

Publications and source records attributed to Gary Poyner.

23 records · Page 2Linked to original sources
arXiv2006

CG Draconis, a particularly active dwarf nova

The dwarf nova CG Dra was intensively monitored during 2005 as part of the Variable Star Sections Recurrent Objects Programme and seven outbursts were detected. These observations were combined with others from the BAA and AAVSO databases which confirmed that the star shows frequent outbursts with a period of around 11 days. Two types of outburst have been detected. Short outbursts lasting about 4 days and long outbursts lasting about 8 days.

astro-ph↗
arXiv2006

CCD photometry and visual observations of V1663 Aquilae (Nova Aquilae 2005)

We present CCD V and I band photometry and visual observations of V1663 Aquilae (Nova Aquilae 2005). This was a classical fast nova, probably of type Ba, observed for the first time on 2005 June 9. Maximum light occurred at HJD= 2453531.2 +/- 0.2, when the apparent V magnitude was 10.7 +/- 0.1 and the V-I colour index 3.1. Decline times were t2,V= 17d, t2,I= 18d, t3,V= 32d and t3,I= 35d. We derived a maximum absolute V magnitude of -7.8 +/- 0.2, colour excess E(B-V)= 2, extinction AV= 6 magnitudes and distance d= 2.9 +/- 0.4 kpc. After maximum the V-I colour index remained between 3.1 and 3.4 for 50 days, then gradually reduced as the nova became bluer with increasing age. We saw no direct evidence of dust emission although this could have contributed to the high extinction in the direction of the nova.

astro-ph↗
arXiv2006

Brief outbursts in the dwarf nova V1316 Cygni

Several brief outbursts were detected in the dwarf nova V1316 Cyg during 2005. These events have an average amplitude of 1.4 magnitude and a duration of <1 to 2 days. Whilst no outburst period could be confirmed, the shortest period between detected events is 10 days. These curious brief outbursts appear to be the normal pattern of behaviour for this system. They are of smaller amplitude and shorter duration than normal outbursts previously reported in this star. V1316 Cyg appears to be a very unusual system and we suggest that further observations by both amateur and professional astronomers could yield important information about the underlying mechanism.

astro-ph↗
arXiv2001

V344 Lyr: an unusual large-amplitude SU UMa-type dwarf nova with a short supercycle

We studied the large-amplitude SU UMa-type dwarf nova V344 Lyr. A combination of our observations and reports to VSNET has yielded an extensive coverage of outbursts between 1994 July and 2001 June. The analysis of this data showed a mean supercycle length of 109.6 d. This value is one of the smallest among known SU UMa-type dwarf novae (except unusual ER UMa-type dwarf novae). The outburst amplitude of V344 Lyr (~5.5 mag) is found to be much larger than those (3.5 +/- 0.3 mag) of SU UMa-type dwarf novae with similar supercycle lengths. Such a deviation of the amplitude in V344 Lyr is difficult to explain by the inclination effect. The extreme outburst parameters of V344 Lyr would require an additional mechanism to effectively reduce the quiescent luminosity or to increase the outburst frequency.

astro-ph↗