AM CVn stars

Below we keep a table with known properties of AM CVn stars.

VALUES LIKE [X] ARE “BEST GUESSES” AND THUS MAY BE COMPLETELY WRONG.VALUES LIKE X? ARE UNCERTAIN.

Period and Pdot from Strohmayer 2005
Newest values (q, M1, M2, i, d) from Roelofs et al. 2010

I corrected Pdot to 3.17e-12 s/s (GN)
Spin-up rate from Ramsay et al 2005
Strohmayer 2004 gives a spin-up rate of 2.3(3)e-12 s/s.
Optical Colours from Ramsay et al 2002
Distance and masses uncertain. The high absorption suggests it is more distant than 100pc, although the exact degree of absorption is uncertain. There is a small probability (~20%) that it is not an ultra-compact binary system (gtbr)
Distance (based on association with G star) from Steeghs et al. 2006

Distance 350pc according to Espaillat et al. 2005, based on direct impact interpretation. GN and co think a disc is more likely (based on the spectra) which would put the system at ~1000pc.

Best determined system: q, i and masses determined from measured central spike and absolute magnitude Roelofs et al,2006, Roelofs et al. 2007b

Distance and system paramters from Roelofs et al. 2007b, based on absolute magnitude

Distance and system paramters from Roelofs et al. 2007b, based on absolute magnitude

Mass ratio based on superhump relation, which is probably not good for AM CVns Roelofs et al,2006

New orbital period (Roelofs et al, submitted). Distance and system paramters from Roelofs et al. 2007b, based on absolute magnitude.

Currently the only known eclipsing AM CVn system Anderson et al 2005
Data on masses, inclination and distance from Copperwheat et al. 2011

Mass ratio based on superhump relation, which is probably not good for AM CVns Roelofs et al,2006

The mass ratio is based on the relationship between the orbital period and the period of 2041.5 sec which is taken to be the superhump period Roelofs et al 2005. These authors note that this relationship may not be well calibrated at these extreme mass ratios and may depend on more than q.

Discovered by Woudt, P. A.; Warner, B.; Rykoff, E.. Period of 2194 sec is likely a superhump period

The mass ratio was derived from an optical spectral analysis Roelofs et al 2005. The same authors estimate the distance based on optical spectra and theoretical spectral modelling.

See Roelofs et al. 2009

Discovered by Anderson et al 2005. Period of 46+/-2 min from spectroscopy (Groot et al. submitted)

Mass ratio from Steeghs et al. in prep. Distance from Roelofs et al,2006 see also Thorstensen 2003.

Discovered by Rau et al 2009. Based on SDSS search Roelofs et al. 2009

Mass ratio from Steeghs et al. in prep. Distance from Thorstensen priv. com.

Discovered by Anderson et al 2005.

Discovered by Anderson et al 2005. Period from Roelofs et al. 2007 (indication already in Anderson et al 2005)

Discovered by Groot et al. (submitted). Possible periods 18 and 26 min, but marginal

Discovered in supernova search: Prieto et al.

Discovered by PJG in podcast of talk at KITP http://online.itp.ucsb.edu/online/snovae07/progenitor/ (Online in streaming video, not in slides)

Turns out not to be an AM CVn star, but a CV with H in its spectrum.

Discovered by Rau et al 2009. Based on SDSS search Roelofs et al. 2009

Discovered by Rau et al 2009. Based on SDSS search Roelofs et al. 2009

Discovered by Rau et al 2009. Based on SDSS search Roelofs et al. 2009