Search Publications
The Unexpected Spectrum of the Innermost Ejecta of the Red Hypergiant VY CMa
Humphreys, Roberta M.; Jones, Terry J.; Gordon, Michael S. +6 more
Hubble Space Telescope/STIS spectra of the small clumps and filaments closest to the central star in VY CMa reveal that the very strong K I emission and TiO and VO molecular emission, long thought to form in a dusty circumstellar shell, actually originate in a few small clumps hundreds of au from the star. The K I lines are 10-20 times stronger in…
Extended main sequence turn-off originating from a broad range of stellar rotational velocities
Lim, Beomdu; Park, Byeong-Gon; Nazé, Yaël +3 more
Star clusters have long been considered to comprise a simple stellar population, but this paradigm is being challenged, since in addition to multiple populations in Galactic globular clusters1, a number of younger star clusters exhibit a significant colour spread at the main sequence turn-off2-9. A sequential evolution of mul…
The backscattering ratio of comet 67P/Churyumov-Gerasimenko dust coma as seen by OSIRIS onboard Rosetta
Lara, L. M.; Bertaux, J. -L.; Lamy, P. +47 more
Remote sensing observations of dust particles ejected from comets provide important hints on the intimate nature of the materials composing these primitive objects. The measurement of dust coma backscattering ratio, BSR, defined as the ratio of the reflectance at phase angle 0° and 30°, helps tuning theoretical models aimed at solving the inverse …
Multiwavelength Period-Luminosity and Period-Luminosity-Color Relations at Maximum Light for Mira Variables in the Magellanic Clouds
Matsunaga, Noriyuki; de Grijs, Richard; Rejkuba, Marina +8 more
We present Period-Luminosity and Period-Luminosity-Color relations at maximum light for Mira variables in the Magellanic Clouds using time-series data from the Optical Gravitational Lensing Experiment (OGLE-III) and Gaia data release 2. The maximum-light relations exhibit a scatter typically up to ∼30% smaller than their mean-light counterparts. T…
The Kitt Peak Electron Multiplying CCD demonstrator
Kulkarni, S. R.; Duev, Dmitry A.; Riddle, Reed +10 more
The Kitt Peak Electron Multiplying CCD (EMCCD) demonstrator is a new instrument that has been developed for use at the Kitt Peak National Observatory's 84-inch telescope. The EMCCD enables single-band optical imaging in the Sloan g and r bands and Johnson UVRI filters. The EMCCD is chosen for its sub-electron effective read noise using large multi…
The Pristine survey - V. A bright star sample observed with SOPHIE
Salvadori, S.; Bonifacio, P.; Caffau, E. +16 more
With the aim of probing the properties of the bright end of the Pristine survey and its effectiveness in selecting metal-poor stars, we selected a sample of bright candidate metal-poor stars combining Pristine CaHK photometry with APASS gi photometry, before the Gaia second data release became available. These stars were observed with the SOPHIE s…
Survival of molecular gas in a stellar feedback-driven outflow witnessed with the MUSE TIMER project and ALMA
Leaman, Ryan; Falcón-Barroso, Jesus; Fragkoudi, Francesca +15 more
Stellar feedback plays a significant role in modulating star formation, redistributing metals, and shaping the baryonic and dark structure of galaxies - however, the efficiency of its energy deposition to the interstellar medium is challenging to constrain observationally. Here we leverage HST and ALMA imaging of a molecular gas and dust shell (M_…
Ultra metal-poor stars: improved atmospheric parameters and NLTE abundances of magnesium and calcium
Sitnova, T. M.; Mashonkina, L. I.; Frebel, A. +1 more
The most metal-poor stars are the oldest objects, they provide a unique opportunity to study the earliest epoch of the Galaxy formation and individual nucleosynthesis events. These stars should be investigated with a scrupulous care, taking into account all available photometric, spectroscopic, and astrometric informations. We determined atmospher…
HATS-54b-HATS-58Ab: Five New Transiting Hot Jupiters Including One with a Possible Temperate Companion
Henning, T.; Mancini, L.; Rabus, M. +18 more
We report the discovery by the HATSouth project of five new transiting hot Jupiters (HATS-54b through HATS-58Ab). HATS-54b, HATS-55b, and HATS-58Ab are prototypical short-period (P = 2.5-4.2 days, R p ∼ 1.1-1.2 {R}{{J}}) hot Jupiters that span effective temperatures from 1350 to 1750 K, putting them in the proposed region o…
VIRTIS-H observations of the dust coma of comet 67P/Churyumov-Gerasimenko: spectral properties and color temperature variability with phase and elevation
Kappel, D.; Erard, S.; Crovisier, J. +14 more
We analyze 2-5 µm spectroscopic observations of the dust coma of comet 67P/Churyumov-Gerasimenko obtained with the Visible InfraRed Thermal Imaging Spectrometer (VIRTIS-H) instrument on board Rosetta from 3 June to 29 October 2015 at heliocentric distances rh = 1.24-1.55 AU. The 2-2.5 µm color, bolometric albedo, and color t…