Search Publications
The First Data Release of the Beijing-Arizona Sky Survey
Fan, Xiaohui; Jiang, Linhua; Cai, Zheng +25 more
The Beijing-Arizona Sky Survey (BASS) is a new wide-field legacy imaging survey in the northern Galactic cap using the 2.3 m Bok telescope. The survey will cover about 5400 deg2 in the g and r bands, and the expected 5σ depths (corrected for the Galactic extinction) in these two bands are g = 24.0 and r = 23.4 mag (AB magnitude). BASS s…
The Horizontal Branch Population of NGC 1851 as Revealed by the Ultraviolet Imaging Telescope (UVIT)
Stalin, C. S.; Rao, N. Kameswara; Murthy, J. +15 more
We present the UV photometry of the globular cluster NGC 1851 using images acquired with the Ultraviolet Imaging Telescope (UVIT) onboard the ASTROSAT satellite. Point-spread function fitting photometric data derived from images in two far-UV (FUV) filters and one near-UV (NUV) filter are used to construct color-magnitude diagrams (CMDs), in combi…
The Prototypical Young L/T-Transition Dwarf HD 203030B Likely Has Planetary Mass
Metchev, Stanimir; Miles-Páez, Paulo A.; Marengo, Massimo +2 more
Upon its discovery in 2006, the young L7.5 companion to the solar analog HD 203030 was found to be ≈ 200 K cooler than older late-L dwarfs, which is quite unusual. HD 203030B offered the first clear indication that the effective temperature at the L-to-T spectral type transition depends on surface gravity: now a well-known characteristic of low-gr…
The Araucaria Project: The Distance to the Fornax Dwarf Galaxy from Near-infrared Photometry of RR Lyrae Stars
Gieren, Wolfgang; Pietrzyński, Grzegorz; Górski, Marek +2 more
We have obtained single-phase near-infrared (NIR) magnitudes in the J and K bands for 77 RR Lyrae (RRL) stars in the Fornax Dwarf Spheroidal Galaxy. We have used different theoretical and empirical NIR period-luminosity-metallicity calibrations for RRL stars to derive their absolute magnitudes, and found a true, reddening-corrected distance modulu…
KELT-18b: Puffy Planet, Hot Host, Probably Perturbed
Bieryla, Allyson; Latham, David W.; Berlind, Perry +54 more
We report the discovery of KELT-18b, a transiting hot Jupiter in a 2.87-day orbit around the bright (V = 10.1), hot, F4V star BD+60 1538 (TYC 3865-1173-1). We present follow-up photometry, spectroscopy, and adaptive optics imaging that allow a detailed characterization of the system. Our preferred model fits yield a host stellar temperature of 667…
D/H Ratios on Saturn and Jupiter from Cassini CIRS
Fletcher, L. N.; Lellouch, E.; Irwin, P. G. J. +7 more
We present new measurements of the deuterium abundance on Jupiter and Saturn, showing evidence that Saturn's atmosphere contains less deuterium than Jupiter's. We analyzed far-infrared spectra from the Cassini Composite Infrared Spectrometer to measure the abundance of HD on both giant planets. Our estimate of the Jovian D/H = (2.95 ± 0.55) × 10
Very Low-mass Stars and Brown Dwarfs in Upper Scorpius Using Gaia DR1: Mass Function, Disks, and Kinematics
Scholz, Aleks; Cook, Neil J.; Jayawardhana, Ray
Our understanding of the brown dwarf population in star-forming regions is dependent on knowing distances and proper motions and therefore will be improved through the Gaia space mission. In this paper, we select new samples of very low-mass objects (VLMOs) in Upper Scorpius using UKIDSS colors and optimized proper motions calculated using Gaia DR…
Resolving the Circumstellar Environment of the Galactic B[e] Supergiant Star MWC 137 from Large to Small Scales
Liimets, Tiina; Kraus, Michaela; Maravelias, Grigoris +10 more
The Galactic object MWC 137 has been suggested to belong to the group of B[e] supergiants. However, with its large-scale optical bipolar ring nebula and high-velocity jet and knots, it is a rather atypical representative of this class. We performed multiwavelength observations spreading from the optical to the radio regimes. Based on optical imagi…
An Estimation of the Star Formation Rate in the Perseus Complex
Myers, Philip C.; Sadavoy, Sarah I.; Lee, Katherine I. +1 more
We present the results of our investigation of the star-forming potential in the Perseus star-forming complex. We build on previous starless core, protostellar core, and young stellar object (YSO) catalogs from Spitzer (3.6-70 µm), Herschel (70-500 µm), and SCUBA (850 µm) observations in the literature. We place the cores and YSO…
Time-series Spectroscopy of the Oscillating Algol-type Binary AB Cas
Koo, Jae-Rim; Lee, Chung-Uk; Kim, Seung-Lee +4 more
This study presents the high-resolution spectra of the eclipsing binary AB Cas with a δ Sct-type pulsating component, which were obtained using the Bohyunsan Optical Echelle Spectrograph in Korea. In this paper, the radial velocities for the primary and secondary stars were measured from a total of 27 spectra made during two nights in 2015 October…