Search Publications
Mysterious Dust-emitting Object Orbiting TIC 400799224
Kostov, Veselin B.; Powell, Brian P.; Rappaport, Saul A. +24 more
We report the discovery of a unique object of uncertain nature-but quite possibly a disintegrating asteroid or minor planet-orbiting one star of the widely separated binary TIC 400799224. We initially identified the system in data from TESS Sector 10 via an abnormally shaped fading event in the light curve (hereafter "dips"). Follow-up speckle ima…
A Radiatively Driven Wind from the η Tel Debris Disk
MacGregor, Meredith A.; Weinberger, Alycia J.; Roberge, Aki +5 more
We present far- and near-ultraviolet absorption spectroscopy of the ~23 Myr edge-on debris disk surrounding the A0V star η Telescopii, obtained with the Hubble Space Telescope Space Telescope Imaging Spectrograph. We detect absorption lines from C I, C II, O I, Mg II, Al II, Si II, S II, Mn II, Fe II, and marginally N I. The lines show two clear a…
Diagnosing Open Cluster Stock 2: Member Candidates and Mass Distribution with Gaia DR2 and LAMOST
Bird, Sarah A.; Zhao, Gang; Liu, Chao +5 more
We identify 1325 member candidates of the open cluster (OC) Stock 2 using data from Gaia DR2. We use the algorithms Clusterix 2.0 and HDBSCAN to select cluster candidates and further refine the final cluster membership by defining neighbors in 5D phase space (Xcp, Ycp, ${Z}_{\mathrm{cp}},\kappa \cdot {\mu }_{\alpha }^{* }$ /ϖ…
The Hubble PanCET program: Transit and Eclipse Spectroscopy of the Hot-Jupiter WASP-74b
Deming, Drake; Nikolov, Nikolay; Mikal-Evans, Thomas +12 more
Planets are like children with each one being unique and special. A better understanding of their collective properties requires a deeper understanding of each planet. Here we add the transit and eclipse spectra of hot-Jupiter WASP-74b into the ever growing data set of exoplanet atmosphere spectral library. With six transits and three eclipses usi…
SCExAO/CHARIS Direct Imaging of A Low-mass Companion At A Saturn-like Separation from an Accelerating Young A7 Star
Currie, Thayne; Kwon, Jungmi; Tamura, Motohide +18 more
We present the SCExAO direct imaging discovery and characterization of a low-mass companion to the nearby young A7IV star, HD 91312. SCExAO/CHARIS JHK (1.1-2.4 µm) spectra and SCExAO/HiCIAO H-band imaging identify the companion over a two year baseline in a highly inclined orbit with a maximum projected separation of 8 au. The companion, HD …
The Sejong Open Cluster Survey (SOS). VII. A Photometric Study of the Young Open Cluster IC 1590
Lim, Beomdu; Bessell, Michael S.; Sung, Hwankyung +2 more
Young open clusters are ideal laboratories to understand the star formation process. We present deep UBVI and Hα photometry for the young open cluster IC 1590 in the center of the H II region NGC 281. Early-type members are selected from UBV photometric diagrams, and low-mass pre-main-sequence (PMS) members are identified by using Hα photometry. I…
Where Do Obscured AGN Fit in a Galaxy's Timeline?
Giavalisco, Mauro; Kirkpatrick, Allison; Ji, Zhiyuan +7 more
Many X-ray bright active galactic nuclei (AGNs) are predicted to follow an extended stage of obscured black hole growth. In support of this picture we examine the X-ray undetected AGNs in the COSMOS field and compare their host galaxies with X-ray bright AGNs. We examine galaxies with M* > 109.5 M⊙ for the prese…
2M17091769+3127589: A Mass-transfer Binary with an Extreme Mass Ratio
Stassun, Keivan G.; Kounkel, Marina; Covey, K. R. +5 more
We present the orbital solution of a peculiar double-lined spectroscopic and eclipsing binary system, 2M17091769+3127589. This solution was obtained by a simultaneous fit of both APOGEE radial velocities and TESS and ASAS-SN light curves to determine masses and radii. This system consists of an $M={0.256}_{-0.006}^{+0.010}$ M⊙, $R={3.96…
Far-ultraviolet Variable Sources in M31
Leahy, Denis; Buick, Megan; Postma, Joseph +1 more
The Ultraviolet Imaging Telescope (UVIT) on board the AstroSat observatory has imaged the Andromeda galaxy (M31) from 2017 to 2019 in the far- and near-UV (FUV and NUV) with the high spatial resolution of ≃1″. The survey covered the large sky area of M31 with a set of observations (Fields), each 28' in diameter. Field 1 was observed in two epochs …
Angular Diameters and Fundamental Parameters of Forty-four Stars from the Navy Precision Optical Interferometer
van Belle, Gerard T.; Schmitt, Henrique R.; Baines, Ellyn K. +9 more
We measured the angular diameters of 44 stars with the Navy Precision Optical Interferometer, obtaining uncertainties on the limb-darkened diameter of 2% or less for all but four stars. We then used our diameters with Gaia or Hipparcos parallaxes to calculate each star's physical radius. We gathered information from the literature to determine bol…