Faint blue objects at high galactic latitude. II - Palomar Schmidt field centered on selected area 29

The orbital and superhump periods of the dwarf nova HS 0417+7445 in Camelopardalis

“…Taking our measured orbital period, P orb = 0.06630354(5) d and our mean superhump period of P sh = 0.06814(11) d, we calculate the superhump period excess ε = 0.028 (1). Such value is consistent with other SU UMa systems of similar orbital period (15) Patterson et al (16) established an empirical relationship between ε and q, the secondary to primary mass ratio: ε = 0.18*q + 0.29*q 2 .…”

Properties and applications of a predicted population of runaway He-sdO/B stars ejected from single degenerate He-donor SNe

“…First identified as a faint blue object showing an ultraviolet excess at high Galactic latitude by Usher et al (1982), then rediscovered as SDSS J093320.86+441705.4 and described by Hirsch et al (2005), who further determined it to possess an exceptionally high radial velocity. Justham et al (2009) argued that a natural explanation for the properties of US 708 is as a surviving helium donor star from a short-period single-degenerate SN Ia progenitor system and that this seemed more satisfying for US 708 than the previously-suggested scenario of dynamical ejection from the Galactic centre (see also Geier et al 2013).…”

Gravitational Wave Astrophysics

“…Not as spectacular as J0651, but still interesting, is the recent discovery of a 20 min detached double WD system in the ELM Survey. WD 0931+444 (SDSS J093506.93+441106.9) was originally identified as a UV excess object (Usher et al 1982). The SDSS spectroscopy of WD 0931+444 clearly shows a composite spectrum of a DA WD plus an M dwarf.…”