RT Journal Article
T1 SDSS J162520.29+120308.7 – a new SU Ursae Majoris star in the period gap
A1 Olech, A.
A1 Miguel Agustino, Enrique de
A1 Otulakowska-Hypka, M.
A1 Thorstensen, J. R.
A1 Rutkowski, A.
A1 Novak, R.
A1 Masi, G.
A1 Richmond, M.
A1 Staels, B.
A1 Lowther, S.
A1 Stein, W.
A1 Ak, T.
A1 Boyd, David
A1 Koff, Robert
A1 Patterson, Joseph
A1 Eker, Z.
AB We report results of an extensive world-wide observing campaign devoted to the recently discovered dwarf novaSDSS J162520.29+120308.7 (SDSS J1625). The data were obtained during the July 2010 eruption of the star and in August andSeptember 2010 when the object was in quiescence. During the July 2010 superoutburst, SDSS J1625 clearly displayed superhumpswith a mean period of Psh = 0.095942(17) days (138.16 ± 0.02 min) and a maximum amplitude reaching almost 0.4 mag. The superhumpperiod was not stable, decreasing very rapidly at a rate of ˙P = −1.63(14) × 10−3 at the beginning of the superoutburst andincreasing at a rate of ˙P = 2.81(20) × 10−4 in the middle phase. At the end of the superoutburst, it stabilized around the value ofPsh = 0.09531(5) day.During the first twelve hours of the superoutburst, a low-amplitude double wave modulation was observed whose properties arealmost identical to early superhumps observed in WZ Sge stars. The period of early superhumps, the period of modulations observedtemporarily in quiescence, and the period derived from radial velocity variations are the same within measurement errors, allowingus to estimate the most probable orbital period of the binary to be Porb = 0.09111(15) days (131.20 ± 0.22 min). This value clearlyindicates that SDSS J1625 is another dwarf nova in the period gap. Knowledge of the orbital and superhump periods allows us toestimate the mass ratio of the system to be q ≈ 0.25. This high value poses serious problems for both the thermal and tidal instability(TTI) model describing the behaviour of dwarf novae and for some models explaining the origin of early superhumps.
PB European Southern Observatory
SN 0004-6361
SN 1432-0746 (electrónico)
YR 2011
FD 2011
LK http://hdl.handle.net/10272/9545
UL http://hdl.handle.net/10272/9545
LA eng
NO Olech, A., Miguel Agustino, E., Otulakowska-Hypka, M., Thorstensen, J.R., Rutkowski, A., Novak, R., Masi, G., Richmond, M., Staels, B., Lowther, S., Stein, W., Ak, T., Boyd, D., Koff, R., Patterson, J., Eker, Z.: "SDSS J162520.29+120308.7 – a new SU Ursae Majoris star in the period gap". Astronomy and Astrophysics. Vol. 532, A64, (2011). ISSN 0004-6361
DS Repositorio Institucional de la Universidad de Huelva
RD 29 may 2026