Search Publications
Eclipsing Binaries as Benchmarks for Trigonometric Parallaxes in the Gaia Era
Torres, Guillermo; Stassun, Keivan G.
We present fits to the broadband photometric spectral energy distributions (SEDs) of 158 eclipsing binaries (EBs) in the Tycho-2 catalog. These EBs were selected because they have highly precise stellar radii, effective temperatures, and in many cases metallicities previously determined in the literature, and thus have bolometric luminosities that…
Parallax Results from URAT Epoch Data
Finch, Charlie T.; Zacharias, Norbert
We present 1103 trigonometric parallaxes and proper motions from the United States Naval Observatory Robotic Astrometric Telescope (URAT) observations taken at the Naval Observatory Flagstaff Station (NOFS) over a three-year period from 2012 April to 2015 June covering the entire sky north of about -10^\circ decl. We selected two samples: previous…
New Orbits Based on Speckle Interferometry at SOAR
Tokovinin, Andrei
The orbits of 55 visual binary stars are computed using recent speckle interferometry data from the SOAR telescope: 33 first-time orbits and 22 revisions of previous orbit calculations. The orbital periods range from 1.4-370 years, and the quality of the orbits ranges from definitive to preliminary and tentative. Most binaries consist of low-mass …
Very Low-mass Stellar and Substellar Companions to Solar-like Stars from MARVELS. VI. A Giant Planet and a Brown Dwarf Candidate in a Close Binary System HD 87646
Bizyaev, Dmitry; Ge, Jian; Schneider, Donald P. +34 more
We report the detections of a giant planet (MARVELS-7b) and a brown dwarf (BD) candidate (MARVELS-7c) around the primary star in the close binary system, HD 87646. To the best of our knowledge, it is the first close binary system with more than one substellar circumprimary companion that has been discovered. The detection of this giant planet was …
Spectroscopic Orbits for 15 Late-type Stars
Abt, Helmut A.; Fekel, Francis C.; Willmarth, Daryl W. +1 more
Spectroscopic orbital elements are determined for 15 stars with periods from 8 to 6528 days with six orbits computed for the first time. Improved astrometric orbits are computed for two stars and one new orbit is derived. Visual orbits were previously determined for four stars, four stars are members of multiple systems, and five stars have Hippar…
The Putative Old, Nearby Cluster Lodén 1 Does Not Exist
Wright, Jason T.; Curtis, Jason L.; Han, Eunkyu
Astronomers have access to precious few nearby, middle-aged benchmark star clusters. Within 500 pc, there are only NGC 752 and Ruprecht 147 (R147) at 1.5 and 3 Gyr, respectively. The Database for Galactic Open Clusters (WEBDA) also lists Lodén 1 as a 2 Gyr cluster at a distance of 360 pc. If this is true, Lodén 1 could become a useful benchmark cl…
Orbits of 12 Southern Binaries Based on Soar Speckle Observations
Docobo, J. A.; Mendez, R. A.; Campo, P. P. +1 more
New data obtained with the 4.1 m Southern Astrophysical Research (SOAR) telescope at Cerro Pachón, Chile, allowed us to revise the orbits and system masses of the following southern visual double stars: WDS 01477-4358 (I 52), WDS 01500-0408 (A 2602), WDS 02514-2139 (DON 43), WDS 03189-0101 (BU 1177), WDS 04142-4608 (RST 2338), WDS 06274-2544 (B 11…
Orbits for Nine Binaries and One Linear Solution
Cvetković, Z.; Pavlović, R.; Ninković, S.
The subject of the present paper is the analysis of the orbital elements for nine binaries: WDS 00463-0634 = HDS 101, WDS 03264+3520 = HDS 430, WDS 03307-1926 = HDS 441, WDS 04025+0638 = HDS 510, WDS 09252+4606 = HDS 1353, WDS 09446+6459 = CHR 176, WDS 10294+1211 = HDS 1507, WDS 10596+1800 = HDS 1568, and WDS 14562+1745 = HDS 2108. The orbital ele…
Lunar Occultations of 18 Stellar Sources from the 2.4 m Thai National Telescope
Dhillon, V. S.; Marsh, T. R.; Richichi, A. +3 more
We report further results from the program of lunar occultation (LO) observations started at the 2.4 m Thai National Telescope (TNT) in 2014. We have recorded LO events of 18 stellar sources, leading to the detection of four angular diameters and two binary stars. With two exceptions, these are first-time determinations. We could resolve angular d…
Long-period Variations in the Radial Velocity of Spectroscopic Binary M Giant µ Ursae Majoris
Lee, Byeong-Cheol; Park, Myeong-Gu; Han, Inwoo +4 more
We report that the spectroscopic binary µ Ursae Majoris (µ UMa) has secondary RV variations of 471.2 days in addition to those of 230.0 days already known. Keplerian orbit analysis yields stellar mass companions of 1.6 M⊙ for the 230 day period and 0.14 M⊙ for the 471 day period. However, the HIPPARCOS photometrie…