Search Publications
Hubble Space Telescope STIS Spectroscopy of Nova T Aurigae 1891
Sion, Edward M.; Godon, Patrick; Larsen, Conor
T Aurigae is an eclipsing old nova that exploded in 1891. At a Gaia EDR3 distance of 815-871 pc, it is a relatively nearby old nova. Through ultraviolet spectral modeling and using the new precise Gaia distance, we find that the HST/STIS spectrum of T Aurigae is consistent with an accretion disk with a mass-transfer rate $\dot{M}$ of the order of …
Constraining the Planet Occurrence Rate around Halo Stars of Potentially Extragalactic Origin
Price-Whelan, Adrian M.; Yoshida, Stephanie; Grunblatt, Samuel
The search for planets orbiting other stars has recently expanded to include stars from galaxies outside the Milky Way. With the Transiting Exoplanet Survey Satellite (TESS) and Gaia surveys, photometric and kinematic information can be combined to identify transiting planet candidates of extragalactic origin. Here, 1080 low-luminosity red-giant b…
BD+47 378: An Eclipsing Binary Containing a δ Sct Pulsating Star
Han, Cheongho; Hong, Kyeongsoo; Rittipruk, Pakakaew +3 more
New high-resolution spectra of the eclipsing binary BD+47 378 were obtained on five nights between 2020 and 2021 with the Bohyunsan Observatory Echelle Spectrograph in Korea. We collected the TESS light curve of the system obtained from Sectors 17 to 18, which shows a flat bottom at the secondary eclipse, an O'Connell effect, and oscillation featu…
The Energetics of the Central Engine in the Powerful Quasar 3C 298
Schneider, Donald P.; Zeimann, Gregory R.; Hill, Gary J. +3 more
The compact steep-spectrum radio source 3C 298 (redshift of 1.44) has the largest 178 MHz luminosity in the Third Cambridge Revised Catalogue (3CR); its radio lobes are among the most luminous in the universe. The plasma state of the radio lobes is modeled with the aid of interferometric radio observations (in particular, the new Low Frequency Arr…
HD 183986: A High-contrast SB2 System with a Pulsating Component
Gajdoš, Pavol; Vaňko, Martin; Pribulla, Theodor +7 more
There is a small group of peculiar early-type stars on the main sequence that show different rotation velocities from different spectral lines. This inconsistency might be due to the binary nature of these objects. We aim to verify this hypothesis by a more detailed spectroscopic and photometric investigation of one such object: HD 183986. We obta…
HST STIS Observations of ζ Aurigae A's Irradiated Atmosphere
Ayres, Thomas R.; Harper, Graham M.; Bennett, Philip D. +3 more
The details of the processes responsible for heating the chromospheres of evolved cool stars remain uncertain. While most spectroscopic diagnostics measure spatially-integrated emission, here we examine diagnostics sensitive to localized atmospheric regions that are specific to cool evolved stars in binary systems with hot main-sequence companions…
X-Ray Emission from Candidate Stellar Merger Remnant TYC 2597-735-1 and Its Blue Ring Nebula
Hoadley, Keri; Schneider, P. C.; Günther, Maximilian N. +3 more
Tight binary or multiple-star systems can interact through mass transfer and follow vastly different evolutionary pathways than single stars. The star TYC 2597-735-1 is a candidate for a recent stellar merger remnant resulting from a coalescence of a low-mass companion with a primary star a few thousand years ago. This violent event is evident in …
Coaxing the Eclipsing Binary V367 Cygni out of Its Shell
Davidge, T. J.
Spectra that cover 0.63-0.69 µm with a spectral resolution ~17,000 are presented of the W Serpentis system V367 Cygni. Absorption lines of Fe II and Si II that form in a circumsystem shell are prominent features, and the depths of these are stable with time, suggesting that the shell is smoothly distributed and well mixed. Further evidence o…
Chemical Abundances of Eight Highly-extincted Milky Way Planetary Nebulae
Dinerstein, Harriet L.; Zeimann, Greg; Sterling, N. C. +1 more
Low- and intermediate-mass (0.8 M ⊙ < M < 8 M ⊙) stars that evolve into planetary nebulae (PNe) play an important role in tracing and driving Galactic chemical evolution. Spectroscopy of PNe enables access to both the initial composition of their progenitor stars and products of their internal nucleosynthesis, but deter…
Challenging the Disk Instability Model. I. The Case of YZ LMi
Baptista, Raymundo; Schlindwein, Wagner
Observations of YZ LMi show enhanced emission along the stream trajectory beyond impact at the disk rim during outbursts as well as when the quiescent disk is large. We investigated whether these features can be explained in terms of either gas stream overflow or penetration within the frameworks of the disk instability model (DIM) and the mass-tr…