45 research outputs found
Transit observations at the observatory in Grossschwabhausen: XO-1b and TrES-1
We report on observations of transit events of the transiting planets XO-1b
and TrES-1 with the AIU Jena telescope in Grossschwabhausen. Based on our IR
photometry (in March 2007) and available transit timings (SuperWASP, XO and
TLC-project-data) we improved the orbital period of XO-1b (P =
3.9414970.000006) and TrES-1 (P = 3.03007370.000006), respectively.
The new ephemeris for the both systems are presented.Comment: 4 pages, 2 figure
T Tauri stars in the SuperWASP and NSVS surveys
We present a study of the long-term optical variability of young T Tauri stars using previously unpublished data from the Super-Wide Angle Search for Planets (SuperWASP) project. Other publicly available photometry from the Northern Sky Variability Survey (NSVS) and the National Aeronautics and Space Administration (NASA) K2 mission were used to check and supplement our results. Our sample includes 20 weak-lined T Tauri stars in the Taurus–Auriga star-forming region. We have performed a period search on the long time-series photometry and derived the mean periods of stars in our sample. We have found new periods for the stars V1334 Tau (HD 283782) and V1349 Tau (HD 31281), which are without any period estimation in the literature. The rotation period was found for the primary star in the binary V773 Tau (HD 283447). Several earlier results were updated. For the star V410 Tau (HD 283518), we have compared the light-curve changes found in previous studies with the new measurements and attributed the evolution of spots to a ∼15-year cycle similar to the solar 11-year cycle. We have also derived luminosities and effective temperatures for our targets, in order to locate them in the Hertzsprung–Russell diagram and calibrate the masses and ages of the target stars
Transit observation at the observatory in Großschwabhausen: XO-1b and TrES-1
We report on observations of transit events of the transiting planets XO-1b and TrES-1 with the AIU Jena telescope in Großschwabhausen. Based on our (IR) photometry (in March 2007) and available transit timings (SuperWASP, XO and TLC-project-data) we improved the orbital period of XO-1b (P = 3.941497 ± 0.000006) and TrES-1 (P = 3.0300737 ± 0.000006), respectively. The new ephemeris for the both systems are presente
Observations of the transiting planet TrES-2 with the AIU Jena telescope in Großschwabhausen
We have started high precision photometric monitoring observations at the AIU Jena observatory in Großschwabhausen near Jena in fall 2006. We used a 25.4cm Cassegrain telescope equipped with a CCD-camera mounted piggyback on a 90cm telescope. To test the attainable photometric precision, we observed stars with known transiting planets. We could recover all planetary transits observed by us. We observed the parent star of the transiting planet TrES-2 over a longer period in Großschwabhausen. Between March and November 2007 seven different transits and almost a complete orbital period were analyzed. Overall, in 31 nights of observation 3423 exposures (in total 57.05h of observation) of the TrES-2 parent star were taken. Here, we present our methods and the resulting light curves. Using our observations we could improve the orbital parameters of the syste
Photometric Analysis of Recently Discovered Eclipsing Binary GSC 00008-00901
Photometric analysis of light curves of newly discovered eclipsing
binary GSC 0008-00901 is presented. The orbital period is improved to
0.28948(11) days. Photometric parameters are determined, as well. The analysis
yielded to conclusion that system is an over-contact binary of W UMa type with
components not in thermal contact. The light curves from 2005 show the presence
of a spot on the surface of one of the components, while light curves from 2006
are not affected by maculation.Comment: Accepted for publication in Astrophysics & Space Scienc
VW LMi: tightest quadruple system known. Light-time effect and possible secular changes of orbits
Tightest known quadruple systems VW LMi consists of contact eclipsing binary
with P_12 = 0.477551 days and detached binary with P_34 = 7.93063 days
revolving in rather tight, 355.0-days orbit. This paper presents new
photometric and spectroscopic observations yielding 69 times of minima and 36
disentangled radial velocities for the component stars. All available radial
velocities and minima times are combined to better characterize the orbits and
to derive absolute parameters of components. The total mass of the quadruple
system was estimated at 4.56 M_sun. The detached, non-eclipsing binary with
orbital period P = 7.93 days is found to show apsidal motion with U
approximately 80 years. Precession period in this binary, caused by the
gravitational perturbation of the contact binary, is estimated to be about 120
years. The wide mutual orbit and orbit of the non-eclipsing pair are found to
be close to coplanarity, preventing any changes of the inclination angle of the
non-eclipsing orbit and excluding occurrence of the second system of eclipses
in future. Possibilities of astrometric solution and direct resolving of the
wide, mutual orbit are discussed. Nearby star, HD95606, was found to form loose
binary with quadruple system VW LMi.Comment: 4 figures. accepted to MNRAS on July 31, 200
The stellar content of the young open cluster Trumpler 37
With an apparent cluster diameter of 1.5{\deg} and an age of ~4 Myr, Trumpler
37 is an ideal target for photometric monitoring of young stars as well as for
the search of planetary transits, eclipsing binaries and other sources of
variability. The YETI consortium has monitored Trumpler 37 throughout 2010 and
2011 to obtain a comprehensive view of variable phenomena in this region. In
this first paper we present the cluster properties and membership determination
as derived from an extensive investigation of the literature. We also compared
the coordinate list to some YETI images. For 1872 stars we found literature
data. Among them 774 have high probability of being member and 125 a medium
probability. Based on infrared data we re-calculate a cluster extinction of
0.9-1.2 mag. We can confirm the age and distance to be 3-5 Myr and ~870 pc.
Stellar masses are determined from theoretical models and the mass function is
fitted with a power-law index of alpha=1.90 (0.1-0.4 M_sun) and alpha=1.12
(1-10 M_sun).Comment: 9 pages, 10 figures, 2 long tables, accepte