Search Publications

Sun-as-a-star Spectral Irradiance Observations of Transiting Active Regions
DOI: 10.3847/1538-4357/abadf9 Bibcode: 2020ApJ...902...36T

Toriumi, Shin; Cheung, Mark C. M.; DeRosa, Marc L. +3 more

Major solar flares are prone to occur in active-region (AR) atmospheres associated with large, complex, dynamically evolving sunspots. This points to the importance of monitoring the evolution of starspots, not only in visible but also in ultraviolet (UV) and X-rays, in understanding the origin and occurrence of stellar flares. To this end, we per…

2020 The Astrophysical Journal
Hinode 26
Galactic extinction laws - I. A global NIR analysis with 2MASS photometry
DOI: 10.1093/mnras/staa1790 Bibcode: 2020MNRAS.496.4951M

García-Lario, P.; Maíz Apellániz, J.; Barbá, R. H. +2 more

We have started an ambitious program to determine if the full diversity of extinction laws is real or if some of it is due to calibration or methodological issues. Here we start by analysing the information on near-infrared (NIR) extinction in a Two Micron All-Sky Survey (2MASS) stellar sample with good quality photometry and very red colours. We …

2020 Monthly Notices of the Royal Astronomical Society
Gaia 26
Optical to Near-infrared Transmission Spectrum of the Warm Sub-Saturn HAT-P-12b
DOI: 10.3847/1538-3881/ab880d Bibcode: 2020AJ....159..234W

Deming, Drake; Nikolov, Nikolay; Sing, David K. +12 more

We present the transmission spectrum of HAT-P-12b through a joint analysis of data obtained from the Hubble Space Telescope Space Telescope Imaging Spectrograph and Wide Field Camera 3 and Spitzer, covering the wavelength range 0.3-5.0 µm. We detect a muted water vapor absorption feature at 1.4 µm attenuated by clouds, as well as a Ray…

2020 The Astronomical Journal
eHST 26
A search for the origin of the interstellar comet 2I/Borisov
DOI: 10.1051/0004-6361/201937231 Bibcode: 2020A&A...634A..14B

Bailer-Jones, Coryn A. L.; Meech, Karen J.; Ye, Quanzhi +2 more

The discovery of the second interstellar object 2I/Borisov on 2019 August 30 raises the question of whether it was ejected recently from a nearby stellar system. Here we compute the asymptotic incoming trajectory of 2I/Borisov, based on both recent and pre-discovery data extending back to December 2018, using a range of force models that account f…

2020 Astronomy and Astrophysics
Gaia 26
Digging for Relics of the Past: The Ancient and Obscured Bulge Globular Cluster NGC 6256
DOI: 10.3847/1538-4357/ab88b3 Bibcode: 2020ApJ...895...54C

Dalessandro, E.; Salaris, M.; Saracino, S. +5 more

We used a set of moderately deep and high-resolution optical observations obtained with the Hubble Space Telescope to investigate the properties of the stellar population in the heavily obscured bulge globular cluster (GC) NGC 6256. The analysis of the color-magnitude diagram (CMD) revealed a stellar population with an extended blue horizontal bra…

2020 The Astrophysical Journal
Gaia eHST 26
ALMA chemical survey of disk-outflow sources in Taurus (ALMA-DOT). I. CO, CS, CN, and H2CO around DG Tau B
DOI: 10.1051/0004-6361/201937247 Bibcode: 2020A&A...636A..65G

Podio, L.; Bacciotti, F.; Fedele, D. +7 more

The chemical composition of planets is determined by the distribution of the various molecular species in the protoplanetary disk at the time of their formation. To date, only a handful of disks have been imaged in multiple spectral lines with high spatial resolution. As part of a small campaign devoted to the chemical characterization of disk-out…

2020 Astronomy and Astrophysics
Gaia 26
SOFIA/HAWC+ Traces the Magnetic Fields in NGC 1068
DOI: 10.3847/1538-4357/ab5849 Bibcode: 2020ApJ...888...66L

Staguhn, Johannes; Ward-Thompson, Derek; Dowell, C. Darren +22 more

We report the first detection of galactic spiral structure by means of thermal emission from magnetically aligned dust grains. Our 89 µm polarimetric imaging of NGC 1068 with the High-resolution Airborne Wideband Camera/Polarimeter (HAWC+) on NASAs Stratospheric Observatory for Infrared Astronomy (SOFIA) also sheds light on magnetic field st…

2020 The Astrophysical Journal
Herschel eHST 26
The Mean Magnetic Field Strength of CI Tau
DOI: 10.3847/1538-4357/ab59d8 Bibcode: 2020ApJ...888..116S

Johns-Krull, Christopher M.; Lee, Jae-Joon; Prato, L. +4 more

We present a blind comparison of two methods to measure the mean surface magnetic field strength of the classical T Tauri star CI Tau based on Zeeman broadening of sensitive spectral lines. Our approach takes advantage of the greater Zeeman broadening at near-infrared compared to optical wavelengths. We analyze a high signal-to-noise, high spectra…

2020 The Astrophysical Journal
Gaia 25
TauREx3 PhaseCurve: A 1.5D Model for Phase-curve Description
DOI: 10.3847/1538-4357/ab9b82 Bibcode: 2020ApJ...898..155C

Changeat, Q.; Al-Refaie, A.

In recent years, retrieval analysis of exoplanet atmospheres have been very successful, providing deep insights on the composition and the temperature structure of these worlds via transit and eclipse methods. Analysis of spectral phase-curve observations, which in theory provide even more information, are still limited to a few planets. In the ne…

2020 The Astrophysical Journal
eHST 25
Significant luminosity differences of two twin Type Ia supernovae
DOI: 10.1093/mnras/stz3324 Bibcode: 2020MNRAS.491.5991F

Filippenko, Alexei V.; Foley, Ryan J.; Riess, Adam G. +5 more

The Type Ia supernovae (SNe Ia) 2011by, hosted in NGC 3972, and 2011fe, hosted in M101, are optical 'twins,' having almost identical optical light-curve shapes, colours, and near-maximum-brightness spectra. However, SN 2011fe had significantly more ultraviolet (UV; 1600 < λ < 2500 Å) flux than SN 2011by before and at peak luminosity. Several…

2020 Monthly Notices of the Royal Astronomical Society
eHST 25