Search Publications

Complex Rotational Modulation of Rapidly Rotating M Stars Observed with TESS
DOI: 10.3847/1538-4357/ab158c Bibcode: 2019ApJ...876..127Z

Dai, F.; Rowden, P.; Seager, S. +23 more

We have searched for short periodicities in the light curves of stars with T eff cooler than 4000 K made from 2-minute cadence data obtained in Transiting Exoplanet Survey Satellite sectors 1 and 2. Herein we report the discovery of 10 rapidly rotating M dwarfs with highly structured rotational modulation patterns among 371 M dwarfs fou…

2019 The Astrophysical Journal
Gaia 41
Demonstration of Magnetic Field Tomography with Starlight Polarization toward a Diffuse Sightline of the ISM
DOI: 10.3847/1538-4357/aafdb2 Bibcode: 2019ApJ...872...56P

Tassis, Konstantinos; Potter, Stephen B.; Liodakis, Ioannis +7 more

The availability of large data sets with stellar distance and polarization information will enable a tomographic reconstruction of the (plane-of-the-sky-projected) interstellar magnetic field in the near future. We demonstrate the feasibility of such a decomposition within a small region of the diffuse interstellar medium (ISM). We combine measure…

2019 The Astrophysical Journal
Gaia 41
The ALMA Lupus protoplanetary disk survey: evidence for compact gas disks and molecular rings from CN
DOI: 10.1051/0004-6361/201834257 Bibcode: 2019A&A...623A.150V

Testi, L.; Tazzari, M.; Williams, J. P. +10 more

Context. The cyanide radical CN is abundant in protoplanetary disks, with line fluxes often comparable to those of 13CO. It is known to be sensitive to UV irradiation of the upper disk atmosphere, with models predicting ring-shaped emission.
Aims: We seek to characterize the CN emission from 94 Class-II disks in the Lupus star-form…

2019 Astronomy and Astrophysics
Gaia 41
SOFIA mid-infrared observations of Supernova 1987A in 2016 - forward shocks and possible dust re-formation in the post-shocked region
DOI: 10.1093/mnras/sty2734 Bibcode: 2019MNRAS.482.1715M

Matsuura, Mikako; Barlow, M. J.; Meixner, Margaret +10 more

The equatorial ring of Supernova (SN) 1987A has been exposed to forward shocks from the SN blast wave, and it has been suggested that these forward shocks have been causing ongoing destruction of dust in the ring. We obtained Stratospheric Observatory For Infrared Astronomy The Faint Object InfraRed CAmera for the SOFIA Telescope (FORCAST) 11.1, 1…

2019 Monthly Notices of the Royal Astronomical Society
Herschel 41
H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia
DOI: 10.1051/0004-6361/201834391 Bibcode: 2019A&A...627A.178F

Schultheis, M.; Minniti, D.; Souto, Diogo +34 more

We present an elemental abundance analysis of high-resolution spectra for five giant stars spatially located within the innermost regions of the bulge globular cluster NGC 6522 and derive Fe, Mg, Al, C, N, O, Si, and Ce abundances based on H-band spectra taken with the multi-object APOGEE-north spectrograph from the SDSS-IV Apache Point Observator…

2019 Astronomy and Astrophysics
Gaia 41
Characterization and formation of on-disk spicules in the Ca II K and Mg II k spectral lines
DOI: 10.1051/0004-6361/201936617 Bibcode: 2019A&A...631L...5B

Joshi, Jayant; Rouppe van der Voort, Luc; Henriques, Vasco M. J. +1 more

We characterize, for the first time, type-II spicules in Ca II K 3934 Å using the CHROMIS instrument at the Swedish 1 m Solar Telescope. We find that their line formation is dominated by opacity shifts with the K3 minimum best representing the velocity of the spicules. The K2 features are either suppressed by the Doppler-shif…

2019 Astronomy and Astrophysics
IRIS 41
New Millimeter CO Observations of the Gas-rich Debris Disks 49 Cet and HD 32297
DOI: 10.3847/1538-4357/ab4272 Bibcode: 2019ApJ...884..108M

Pascucci, Ilaria; Hughes, A. Meredith; Moór, Attila +7 more

Previous observations revealed the existence of CO gas at nearly protoplanetary level in several dust-rich debris disks around young A-type stars. Here we used the Atacama Large Millimeter/submillimeter Array (ALMA) 7 m Array to measure 13CO and C18O emission toward two debris disks, 49 Cet and HD 32297, and detected similarl…

2019 The Astrophysical Journal
Gaia 41
NGTS-7Ab: an ultrashort-period brown dwarf transiting a tidally locked and active M dwarf
DOI: 10.1093/mnras/stz2496 Bibcode: 2019MNRAS.489.5146J

Jackman, James A. G.; Wheatley, Peter J.; Moyano, Maximiliano +36 more

We present the discovery of NGTS-7Ab, a high-mass brown dwarf transiting an M dwarf with a period of 16.2 h, discovered as part of the Next Generation Transit Survey (NGTS). This is the shortest period transiting brown dwarf around a main or pre-main sequence star to date. The M star host (NGTS-7A) has an age of roughly 55 Myr and is in a state of…

2019 Monthly Notices of the Royal Astronomical Society
Gaia XMM-Newton 41
A Jovian planet in an eccentric 11.5 day orbit around HD 1397 discovered by TESS
DOI: 10.1051/0004-6361/201834577 Bibcode: 2019A&A...623A.100N

Bouchy, F.; Stassun, K.; Winn, J. N. +49 more

The Transiting Exoplanet Survey Satellite TESS has begun a new age of exoplanet discoveries around bright host stars. We present the discovery of HD 1397b (TOI-120.01), a giant planet in an 11.54-day eccentric orbit around a bright (V = 7.9) G-type subgiant. We estimate both host star and planetary parameters consistently using EXOFASTv2 based on …

2019 Astronomy and Astrophysics
Gaia 41
Properties of Slow Magnetoacoustic Oscillations of Solar Coronal Loops by Multi-instrumental Observations
DOI: 10.3847/2041-8213/ab0c9f Bibcode: 2019ApJ...874L...1N

Moon, Y. -J.; Nakariakov, V. M.; Kumar, P. +3 more

Rapidly decaying oscillations of the thermal emission detected in the decay phase of solar and stellar flares are usually interpreted as standing or sloshing (reflecting) slow magnetoacoustic oscillations. We determine the scalings of the oscillation periods, damping times, and amplitudes with the temperature, considering both standing and sloshin…

2019 The Astrophysical Journal
Hinode SOHO 41