Search Publications
Properties of F Stars with Stable Radial Velocity Timeseries: A Useful Metric for Selecting Low-jitter F Stars
Wright, Jason T.; Isaacson, Howard; Luhn, Jacob K.
In a companion paper, we have conducted an in-depth analysis of radial velocity jitter of over 600 stars, examining the astrophysical origins including stellar granulation, oscillation, and magnetic activity. In this paper, we highlight a subsample of those stars, specifically the main sequence and "retired" F stars -- which we refer to as "MSRF" …
A Mystery in Chamaeleon: Serendipitous Discovery of a Galactic Symbiotic Nova
Ting, Yuan-Sen; Greene, Jenny E.; Pope, Benjamin J. S. +3 more
We present the serendipitous discovery of a low optical-luminosity nova occurring in a D-type symbiotic binary star system in the Milky Way. We lay out the extensive archival data alongside new follow-up observations related to the stellar object CN Cha in the constellation of Chamaeleon. The object had long period (250 days), high amplitude (3 ma…
Orbits for Eight Binaries
Cvetković, Z.; Pavlović, R.
The subject of the present paper is the analysis of the orbital solutions for eight binaries: WDS 02402+0436 = HDS 347, WDS 02552+5950 = MLR 520, WDS 03119+6131 = HDS 407, WDS 04570+7350 = YSC 145, WDS 05202+4105 = HDS 701, WDS 06467+0822 = HDS 940AB, WDS 08259-1623 = HDS 1199, and WDS 22550+5132 = HU 785. Seven orbits are determined for the first…
WIYN Open Cluster Study LXXX: HDI CCD UBVRI Photometry of the Old Open Cluster NGC 7142 and Comparison to M67
Twarog, Bruce A.; Anthony-Twarog, Barbara J.; Deliyannis, Constantine P. +2 more
We present UBVRI photometry of 8702 stars in a 0°5 × 0°5 field in the direction of NGC 7142, taken with the Half Degree Imager at the WIYN 0.9 m telescope, to improve knowledge of this cluster's basic parameters. Our photometry spans the ranges 10.6-20.4 mag in U, 10.6-22.0 mag in B, 10.0-21.8 mag in V, 9.2-20.7 mag in R, and 8.5-19.9 mag in I. Us…
Revisiting the Architecture of the KOI-89 System
Tamayo, Daniel; Masuda, Kento
While high stellar obliquities observed in exoplanetary systems may be attributed to processes that tilt the planetary orbits, it is also possible that they reflect misalignments between protoplanetary disks and stellar spins. This latter hypothesis predicts the presence of coplanar multiplanetary systems misaligned with their central stars. Here …
KMT-2016-BLG-1836Lb: A Super-Jovian Planet from a High-cadence Microlensing Field
Han, Cheongho; Lee, Chung-Uk; Zang, Weicheng +24 more
We report the discovery of a super-Jovian planet in the microlensing event KMT-2016-BLG-1836, which was found by the Korea Microlensing Telescope Network (KMTNet) high-cadence observations ( ${\rm{\Gamma }}\sim 4\,{\mathrm{hr}}^{-1}$ ). The planet-host mass ratio q ∼ 0.004. A Bayesian analysis indicates that the planetary system is composed of a s…
Evidence for Transparency and Clumps in the Circumbinary Ring of the T Tauri Star V582 Mon (KH 15D)
Winn, Joshua N.; Herbst, William; Newmark, Amanda +3 more
The binary T Tauri star V582 Mon (KH 15D) is surrounded by a tilted and nodally precessing ring of dusty material, which has caused periodic occultations of one or both stars over the last 50 years. Here, we present multi-color time-series photometry (VRIJHK) throughout the 2017/2018 observing season, when the ring was covering the entire orbit of…
Pleiades or Not? Resolving the Status of the Lithium-rich M Dwarfs HHJ 339 and HHJ 430
Oppenheimer, Rebecca; Aigrain, Suzanne; Hillenbrand, Lynne A. +7 more
Oppenheimer et al. discovered two M5 dwarfs in the Pleiades with nearly primordial lithium. These stars are not low enough in mass to represent the leading edge of the lithium depletion boundary at Pleiades age (∼125 Myr). A possible explanation for the enhanced lithium in these stars is that they are actually not members of the Pleiades but inste…
Effective Opacity of the Intergalactic Medium from Galaxy Spectra Analysis
Chisholm, John; Prochaska, J. Xavier; Lee, Khee-Gan +1 more
We measure the effective opacity ( ${\tau }_{\mathrm{eff}}$ ) of the intergalactic medium from the composite spectra of 281 Lyman-break galaxies in the redshift range 2 ≲ z ≲ 3. Our spectra are taken from the COSMOS Lyα Mapping And Tomographic Observations survey derived from the Low Resolution Imaging Spectrometer on the W.M. Keck I telescope. We…
The Hubble Space Telescope Advanced Camera for Surveys Emission Line Survey of Andromeda. I. Classical Be Stars
Dalcanton, J. J.; Choi, Y.; Johnson, L. C. +9 more
We present results from a two epoch Hubble Space Telescope Hα emission line survey of the Andromeda galaxy that overlaps the footprint of the Panchromatic Hubble Andromeda Treasury (PHAT) survey. We found 552 (542) classical Be stars and 8429 (8556) normal B-type stars in epoch # 1 (epoch # 2), yielding an overall fractional Be content of 6.15% ± …