Search Publications
The Pulsating Eclipsing Binary TIC 309658221 in a 7.59-day Orbit
Kristiansen, Martti H.; Hong, Kyeongsoo; Lee, Jae Woo
We present a new eclipsing binary (EB) showing multiperiodic oscillations using the first three sectors of Transiting Exoplanet Survey Satellite (TESS) photometry. The eclipse and pulsation light curves of TIC 309658221 were modeled using an iterative method to obtain a consistent photometric solution. The TESS target is a circular-orbit, detached…
Radial Velocities in the Outermost Disk toward the Anticenter
Allende Prieto, C.; López-Corredoira, M.; Sylos Labini, F. +1 more
We measure the mean Galactocentric radial component of the velocity of stars (v R ) in the disk at 8 kpc < R < 28 kpc in the direction of the anticenter. For this, we use the Apache Point Galactic Evolution Experiment. Furthermore, we compare the result with H I maps along the same line of sight. We find an increase in positive (…
X-Ray Observations of an Intermediate Polar V2400 Oph
Pandey, J. C.; Singh, Harinder P.; Joshi, Arti
Based on the X-ray observations from XMM-Newton and Suzaku satellites at four different epochs, we present temporal and spectral properties of an intermediate polar (IP) V2400 Oph (=RX J1712.6-2414). The X-ray variations are found to occur at the spin and synodic periods and are derived to be 929 s and 1003 s, respectively. The X-ray spectrum is s…
The Discovery of Quasi-stellar Objects behind M31 and M33
Massey, Philip; Levesque, Emily M.; Neugent, Kathryn F.
We report the discovery of 11 newly found quasars behind the stellar disks of the spiral galaxies M31 and M33 in the fields covered by the Local Group Galaxy Survey. Their redshifts range from 0.37 to 2.15. Most are X-ray, ultraviolet, and infrared sources. We also report the discovery of five normal background galaxies. Most of these objects were…
Active Asteroid P/2017 S5 (ATLAS)
Mutchler, Max; Kotulla, Ralf; Jewitt, David +7 more
Observations of active asteroid P/2017 S5 when near perihelion reveal the ejection of large (102-104 µm) particles at 0.2-2 m s-1 speeds, with estimated mass-loss rates of a few kg s-1. The protracted nature of the mass loss (continuous over ∼150 days) is compatible with a sublimation origin, meani…
Identification of Stellar Flares Using Differential Evolution Template Optimization
Kowalski, Adam F.; Wisniewski, John P.; Bellm, Eric C. +2 more
We explore methods for the identification of stellar flare events in irregularly sampled data of ground-based time domain surveys. In particular, we describe a new technique for identifying flaring stars, which we have implemented in a publicly available Python module called “PyVAN.” The approach uses the Differential Evolution algorithm to optimi…
New Constraint on the Atmosphere of (50000) Quaoar from a Stellar Occultation
Kobayashi, Naoto; Maehara, Hiroyuki; Matsunaga, Noriyuki +35 more
We report observations of a stellar occultation by the classical Kuiper Belt object (50000) Quaoar that occurred on 2019 June 28. A single-chord high-cadence (2 Hz) photometry data set was obtained with the Tomo-e Gozen CMOS camera mounted on the 1.05 m Schmidt telescope at Kiso Observatory. The obtained ingress and egress data do not show any ind…
Circumnuclear Rings and Lindblad Resonances in Spiral Galaxies
Díaz, R. J.; Agüero, M. P.; Gaspar, G. +5 more
In order to study the location of circumnuclear rings (CNR) and their possible relation with the inner Lindblad resonances (ILR), we investigate a sample of spiral galaxies. For this purpose, we have obtained and analyzed medium resolution spectra of five spiral galaxies in the range 6200-6900 Å. Through the Hα emission line, we constructed the ra…
Photometric and Spectral Observations of the W UMa Stars NSVS 4161544 and 1SWASP J034501.24+493659.9. GAIA Challenges
Kjurkchieva, Diana; Popov, Velimir A.; Stateva, Ivanka +1 more
Photometric and spectral observations of the W UMa binaries NSVS 4161544 and 1SWASP J034501.24+493659.9 with periods of around 8 hr are presented. The simultaneous light-curve and radial-velocity-curve solutions revealed that the two targets have over-contact configurations, and their components undergo partial eclipses. The derived parameters of …
Time-series Spectroscopy of the Oscillating Eclipsing Algol System V392 Orionis
Koo, Jae-Rim; Han, Cheongho; Kim, Seung-Lee +5 more
We present the results from a detailed analysis of our high-resolution spectra and historical photometric observations of the semidetached eclipsing binary V392 Ori with a δ Scuti (δ Sct) pulsating component. A total of 31 spectroscopic observations were carried out at both the Bohyunsan Optical Astronomy Observatory in Korea and the Thai National…