Search Publications
HD 145263: Spectral Observations of Silica Debris Disk Formation via Extreme Space Weathering?
Sitko, M. L.; Marengo, M.; Chen, C. H. +9 more
We report here time-domain infrared spectroscopy and optical photometry of the HD 145263 silica-rich circumstellar-disk system taken from 2003 through 2014. We find an F4V host star surrounded by a stable, massive 1022-1023 kg (MMoon to MMars) dust disk. No disk gas was detected, and the primary star was…
The Big Sibling of AU Mic: A Cold Dust-rich Debris Disk around CP-72 2713 in the β Pic Moving Group
Pascucci, Ilaria; Pál, András; Hughes, A. Meredith +8 more
Analyzing Spitzer and Herschel archival measurements we identified a debris disk around the young K7/M0 star CP-72 2713. The system belongs to the 24 Myr old β Pic moving group. Our new 1.33 mm continuum observation, obtained with the Atacama Large Millimeter/submillimeter Array 7 m array, revealed an extended dust disk with a peak radius of 140 a…
A Multiwavelength Search for Intrinsic Linear Polarization in Wolf-Rayet Winds
Moffat, Anthony F. J.; Fullard, Andrew G.; Manset, Nadine +3 more
Wolf-Rayet stars have strong, hot winds, with mass-loss rates at least a factor of 10 greater than their O-star progenitors, although their terminal wind speeds are similar. In this paper, we use the technique of multiband linear polarimetry to extract information on the global asymmetry of the wind in a sample of 47 bright Galactic WR stars. Our …
Mutual inclinations between giant planets and their debris discs in HD 113337 and HD 38529
Wyatt, Mark C.; Kennedy, Grant M.; Xuan, Jerry W. +1 more
HD 113337 and HD 38529 host pairs of giant planets, a debris disc, and wide M-type stellar companions. We measure the disc orientation with resolved images from Herschel and constrain the three-dimensional orbits of the outer planets with Gaia DR2 and Hipparcos astrometry. Resolved disc modelling leaves degeneracy in the disc orientation, so we de…
High-speed stars: Galactic hitchhikers
Bonifacio, P.; Caffau, E.; Spite, M. +8 more
Context. The search for stars born in the very early stages of the Milky Way star formation history is of paramount importance in the study of the early Universe since their chemistry carries irreplaceable information on the conditions in which early star formation and galaxy buildup took place. The search for these objects has generally taken the…
A new white dwarf companion around the Δµ star GJ 3346
Sozzetti, A.; D'Orazi, V.; Zurlo, A. +7 more
We present the discovery of a white dwarf companion at ∼3.6 arcsec from GJ 3346, a nearby (π ∼ 42 mas) K star observed with SPHERE@VLT as part of an open time survey for faint companions to objects with significant proper motion discrepancies (Δµ) between Gaia DR1 and Tycho-2. Syrius-like systems like GJ 3346 AB, which include a main-sequenc…
Mass-to-light Ratios of Spatially Resolved Stellar Populations in M31
Bell, Eric F.; Dolphin, Andrew E.; Williams, Benjamin F. +4 more
A galaxy's stellar mass-to-light ratio (M_{\star }/L) is a useful tool for converting luminosity to stellar mass (M_{\star }). However, the practical utility of M_{\star}/L inferred from stellar population synthesis (SPS) models is limited by mismatches between the real and assumed models for star-formation history (SFH) and dust geometry, both of…
Discovery of a pre-cataclysmic binary with unusual chromaticity of the eclipsed white dwarf by the GPX survey
Barkaoui, Khalid; Gillon, Michaël; Jehin, Emmanuël +14 more
We report the discovery of a relatively bright eclipsing binary system, which consists of a white dwarf (WD) and a main-sequence K7 star with clear signs of chromospheric and spot activity. The light curve of this system shows ∼0.2 mag ellipsoidal variability with a period of 0.297549 d and a short total eclipse of the WD. Based on our analysis of…
DY Pegasi: An SX Phoenicis Star in a Binary System with an Evolved Companion
Xue, Hui-Fang; Niu, Jia-Shu
In this work, the photometric data from the American Association of Variable Star Observers are collected and analyzed on the SX Phoenicis star DY Pegasi (DY Peg). From the frequency analysis, we get three independent frequencies: f0 = 13.71249 c d-1, f1 = 17.7000 c d-1, and f2 = 18.138 c d
Possible Transient Luminous Events Observed in Jupiter's Upper Atmosphere
Wong, Michael H.; Gérard, Jean-Claude; Kammer, Joshua A. +10 more
Eleven transient bright flashes were detected in Jupiter's atmosphere using the ultraviolet spectrograph instrument on the Juno spacecraft. These bright flashes are only observed in a single spin of the spacecraft and their brightness decays exponentially with time, with a duration of ∼1.4 ms. The spectra are dominated by H2 Lyman band …