Search Publications
V1294 Aql = HD 184279: A bad boy among Be stars or an important clue to the Be phenomenon?
Wolf, M.; Chini, R.; Harmanec, P. +21 more
A reliable determination of the basic physical properties and variability patterns of hot emission-line stars is important for understanding the Be phenomenon and ultimately, the evolutionary stage of Be stars. This study is devoted to one of the most remarkable Be stars, V1294 Aql = HD 184279. We collected and analysed spectroscopic and photometr…
Kepler Bonus: Aperture Photometry Light Curves of EXBA Sources
Hedges, Christina; Rodriguez, Joseph E.; Barentsen, Geert +2 more
NASA's Kepler mission observed background regions across its field of view for more than 3 consecutive yr using custom designed superapertures (EXBA masks). Since these apertures were designed to capture a region of the sky rather than single targets, the Kepler Science Data Processing Pipeline produced target pixel files but did not produce light…
Nova Sagittarii 1943 (V1148 Sgr): A Luminous Red Nova?
Bond, Howard E.; Mink, Jessica; Doane, Alison +1 more
Nova Sagittarii 1943 (V1148 Sgr) was an eighth magnitude optical transient that was unusual in having a late-type spectrum during its outburst, in striking contrast to the normal high-excitation spectra seen in classical novae. Unfortunately, only an approximate position was given in the discovery announcement, hampering follow-up attempts to obse…
Diffuse x-ray and gamma-ray limits on boson stars that interact with nuclei
Acevedo, Javier F.; Bhoonah, Amit; Bramante, Joseph
Light bosonic dark matter can form gravitationally bound states known as boson stars. In this work, we explore a new signature of these objects interacting with the interstellar medium (ISM). We show how small effective couplings between the bosonic dark matter and the nucleon lead to a potential that accelerates ISM baryons as they transit the bo…
Updated Photon Scattering Coefficients (g_values) for Mercury's Exospheric Species
Killen, Rosemary M.; Vervack, Ronald J., Jr.; Burger, Matthew H.
In an optically thin exosphere such as those of Mercury and the Moon, the optically stimulated emissions are directly proportional to the stimulating solar flux. An important quantity in relating measured emission to column abundance in remote-sensing observations is the g_value. The g_value is proportional to the f-value of the emission line and …
Comparison of the active galactic nuclei Baldwin effect with the modified Baldwin effect of the ultraviolet-optical emission lines in a single sample
Shang, Zhaohui; Brotherton, Michael S.; Wang, Yongjiang +1 more
The inverse relationship between equivalent width (EW) of broad emission lines and the underlying continuum luminosity, known as the Baldwin effect (BE), is an important and well-studied correlation in active galactic nuclei (AGNs). However, the EW is also considered to be anticorrelated with the Eddington ratio, referred to as the modified Baldwi…
Pre-landslide topographic reconstruction in Baetis Chaos, mars using a CaSSIS Digital Elevation Model
Mangold, N.; Pajola, M.; Cremonese, G. +8 more
Planview detailed morphological analysis of martian landslides is usually performed using orbital imagery such as from the ConTeXt camera (CTX) at 6 m/pix, the Colour and Stereo Surface Imaging System (CaSSIS) at 4.5 m/pix or the High-Resolution Imaging Science Experiment (HiRISE) at 0.25-0.5 m/pix. However, topographic information is key to fully…
Gaia DR2 and EDR3 data and evolutionary status of post-AGB stars with high radial velocities
Matsuno, Tadafumi; Aoki, Wako; Parthasarathy, Mudumba
Using the Gaia Data Release 2 (DR2) and Early Data Release 3 (EDR3) data and list of post-AGB candidates, we investigate the parallax, proper motion, and binarity for 20 post-AGB stars and candidates that have high radial velocities. From their Gaia distances, their luminosities and kinematics are derived. The evolutionary status of these stars is…
The Small Separation A-star Companion Population: First Results with CHARA/MIRC-X
Lanthermann, Cyprien; Anugu, Narsireddy; Kraus, Stefan +9 more
We present preliminary results from our long-baseline interferometry (LBI) survey to constrain the multiplicity properties of intermediate-mass A-type stars within 80 pc. Previous multiplicity studies of nearby stars exhibit orbital separation distributions well fitted with a lognormal with peaks >15 au, increasing with primary mass. The A-star…
Identification and Parameter Determination of F-type Herbig Stars from LAMOST DR8
Luo, A. -Li; Hou, Wen; Jiang, Biwei +5 more
We identify 20 F-type Herbig stars and provide a list of 22 pre-main-sequence candidates from LAMOST DR8. The effective temperature, distance, extinction, stellar luminosity, mass, age, and radius are derived for each Herbig star based on optical spectra, photometry, Gaia EDR3 parallaxes, and pre-main-sequence evolutionary tracks. According to spe…