Search Publications
Discovery of a young pre-intermediate polar
Hermes, J. J.; Drake, Jeremy J.; Landstreet, John D. +4 more
We present the discovery of a magnetic field on the white dwarf component in the detached post-common envelope binary (PCEB) CC Cet. Magnetic white dwarfs in detached PCEBs are extremely rare, in contrast to the high incidence of magnetism in single white dwarfs and cataclysmic variables. We find Zeeman-split absorption lines in both ultraviolet H…
Multiwavelength observations reveal a faint candidate black hole X-ray binary in IGR J17285-2922
Maccarone, T. J.; Degenaar, N.; Wijnands, R. +18 more
IGR J17285-2922 is a known X-ray binary with a low peak 2-10 keV X-ray luminosity of ~ 1036 erg s-1 during outburst. IGR J17285-2922 exhibited two outbursts in 2003 and 2010 and went into outburst again in 2019. We have monitored this ~ 4-month long 2019 outburst with Swift in X-ray and the Very Large Array in radio. We have …
Individual dynamical masses of DENIS J063001.4-184014AB reveal a likely young brown dwarf triple
Martín, E. L.; Sahlmann, J.; Burgasser, A. J. +6 more
The binary nature of the M8.5 dwarf DENIS J063001.4-184014AB (DE0630-18) was discovered with astrometric monitoring from the ground, which determined the unresolved photocentric orbit and the trigonometric parallax of the system. Here we present radial velocity monitoring and resolved observations in the near-infrared with Keck aperture masking th…
Mode identification and seismic study of δ Scuti, the prototype of a class of pulsating stars
Handler, G.; Pigulski, A.; Daszyńska-Daszkiewicz, J. +3 more
We present a seismic study of δ Scuti based on a mode identification from multicoulor photometry. The dominant frequency can be associated only with a radial mode and the second frequency is, most probably, a dipole mode. The other six frequencies have more ambiguous identifications. The photometric mode identification provided also some constrain…
Estimating Teff, radius, and luminosity of M-dwarfs using high-resolution optical and NIR spectral features
Baug, Tapas; Mondal, Soumen; Das, Ramkrishna +1 more
We estimate effective temperature (Teff), stellar radius, and luminosity for a sample of 271 M-dwarf stars (M0V-M7V) observed as a part of CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs) radial-velocity planet survey. For the first time, using the simultaneou…
New Herbig-Haro objects and outflows in the Mon R1 association
Movsessian, T. A.; Magakian, T. Yu; Dodonov, S. N.
We present the results of a narrow-band Hα and [S II] imaging survey of the Mon R1 association performed with the 1-m Schmidt telescope at Byurakan Observatory. Our observations covered a 1° field near the centre of the association. As a result of this study, 20 new Herbig-Haro knots were discovered, some of which form collimated outflows. Among t…
ALMA-IRDC - II. First high-angular resolution measurements of the 14N/15N ratio in a large sample of infrared-dark cloud cores
Caselli, P.; Pineda, J. E.; Jiménez-Serra, I. +6 more
The 14N/15N ratio in molecules exhibits a large variation in star-forming regions, especially when measured from N2H+ isotopologues. However, there are only a few studies performed at high-angular resolution. We present the first interferometric survey of the 14N/15N ratio in N…
Blast from the past: constraining progenitor models of SN 1972E
Schweizer, François; Shappee, Benjamin J.; Tonry, John L. +7 more
We present a novel technique to study Type Ia supernovae (SNe Ia) by constraining surviving companions of historical extragalactic SN by combining archival photographic plates and Hubble Space Telescope(HST) imaging. We demonstrate this technique for Supernova 1972E, the nearest known SN Ia in 125 yr. Some models of SNe Ia describe a white dwarf w…
Gaia DR2 giants in the Galactic dust - II. Application of the reddening maps and models
Gontcharov, George A.; Mosenkov, Aleksandr V.
We exploit a complete sample of 101 810 Gaia DR2 giants, selected in Paper I in the space cylinder with a radius of 700 pc around the Sun and a height of |Z| = 1800 pc, using the Gaia DR2 parallaxes, GBP and GRP photometry, and WISE W3 photometry. We explain the spatial variations of the modes of the observables GBP
Asteroseismology of RRab variable star EZ Cnc from K2 photometry and LAMOST spectroscopy
Zong, Weikai; Fu, Jian-Ning; Wang, Jiaxin +2 more
EZ Cnc, or EPIC 212182292, is a non-Blažko RRab variable star located in the field of K2 Campaign 16. Its atmospheric parameters (Teff, log g, [M/H]) and radial velocities are measured from the 55 high-quality LAMOST medium-resolution spectra. The fundamental frequency of pulsation is derived as f = 1.8323(17) d-1 from the K2…