Search Publications

Role of the Coronal Environment in the Formation of Four Shocks Observed without Coronal Mass Ejections at Earth's Lagrangian Point L1
DOI: 10.3847/1538-4357/ab8fae Bibcode: 2020ApJ...895..144P

Pick, M.; Magdalenić, J.; Bocchialini, K. +3 more

The main goal of this study is to determine the solar origin of four single shocks observed at the Lagrange point L1 and followed by storm sudden commencements (SSCs) during 2002. We look for associated coronal mass ejections (CMEs), starting from estimates of the transit time from Sun to Earth. For each CME, we investigate its association with a …

2020 The Astrophysical Journal
SOHO 2
Long-term Activity in Photospheres of Low-mass Stars with Strong Magnetic Fields
DOI: 10.1134/S0016793220070075 Bibcode: 2020Ge&Ae..60..942B

Bondar', N. I.; Katsova, M. M.

The behavior of the average annual luminosity of K–M dwarfs OU Gem, EQ Vir, V1005 Ori and AU Mic was studied at time intervals of several decades. The main sources of photometric data for 1989–2019 were the Hipparcos, ASAS, KWS databases. An analysis of long-term series showed that the average annual brightness of all stars varies cyclical. The du…

2020 Geomagnetism and Aeronomy
Hipparcos 2
Exoplanets in the Antarctic Sky. IV. Dual-band Photometry of Variables Found by the CSTAR-II Commissioning Survey at the North Sky
DOI: 10.3847/1538-3881/ab7449 Bibcode: 2020AJ....159..172Z

Wittenmyer, Robert A.; Wang, Lifan; Yang, Ming +30 more

From the experiences learned in three decades of exoplanet search, wide-field transit surveys have proven to be one of the most effective ways to detect exoplanets. Wide field of view, however, suffers from high false-positive rates caused by blended eclipsing binaries. The chromaticity in eclipse depth is an effective feature to distinguish low-d…

2020 The Astronomical Journal
Gaia 2
Discovery of deep eclipses in the cataclysmic variable IPHAS J013031.89+622132.3
DOI: 10.1016/j.newast.2019.101350 Bibcode: 2020NewA...7701350K

Kozhevnikov, V. P.

I performed photometric observations of the poorly studied cataclysmic variable IPHAS J013031.89+622132.3 and discovered very deep eclipses. I obtained observations over 14 nights for a total time of 50 hours during a time span of 6 months. Thanks to the long observation interval, I determined the orbital period with high precision, Porb

2020 New Astronomy
Gaia 2
Broadband X-Ray Observation of Broad-line Radio Galaxy 3C 109
DOI: 10.3847/1538-4357/ab94a2 Bibcode: 2020ApJ...897...47C

Fabian, Andrew C.; Kara, Erin; Lohfink, Anne M. +1 more

We present a study of the central engine in the broad-line radio galaxy 3C 109. To investigate the immediate surrounding of this accreting, supermassive black hole, we perform a multiepoch broadband spectral analysis of a joint NuSTAR/XMM observation (2017), an archival XMM observation (2005) and the 105 month averaged Swift-BAT data. We are able …

2020 The Astrophysical Journal
XMM-Newton 2
The K supergiant runaway star HD 137071
DOI: 10.1051/0004-6361/202038136 Bibcode: 2020A&A...638A..90C

Comerón, F.; Figueras, F.

Context. Extensive work exists on runaway massive stars with peculiar motions that are much higher than those typical of the extreme Population I to which they belong. Work on runaways has focused almost exclusively on O and B stars, most of which undergo a red supergiant phase before ending their lives as supernovae. Very few examples are known o…

2020 Astronomy and Astrophysics
Gaia 2
Detection and characterization of stellar magnetic activity with Gaia
DOI: 10.1002/asna.202013732 Bibcode: 2020AN....341..508D

Lanzafame, Alessandro; Distefano, Elisa

The Gaia Data Release 2 (DR2) supplied a catalog of 147,644 late-type stars for which the analysis of the G-band photometric time series allowed the detection of the rotation period and an estimate of the magnetic activity level. The Gaia DR3 will be based on photometric time series spanning a longer time interval and will allow the detection and …

2020 Astronomische Nachrichten
Gaia 2
The near-infrared polarization of the pre-planetary nebula Frosty Leo
DOI: 10.1093/mnras/staa1291 Bibcode: 2020MNRAS.495.2599S

Luna, A.; Sabin, L.; Mayya, Y. D. +3 more

We present a near-infrared imaging polarimetric study of the pre-planetary nebula: Frosty Leo. The observations were carried out in J, H, and K' bands using the new polarimeter POLICAN mounted on the 2.1-m telescope of the Guillermo Haro Astrophysical Observatory, Sonora, Mexico. The most prominent result observed in the polarization maps is a lar…

2020 Monthly Notices of the Royal Astronomical Society
eHST 2
EUV Wave Detection and Characterization Using Deep Learning
DOI: 10.1007/s11207-020-01612-4 Bibcode: 2020SoPh..295...44X

Liu, Sixuan; Xu, Long; Yan, Yihua +1 more

Coronal Mass Ejections (CMEs) are the most violent solar bursts. They cause severe disturbances in the solar-terrestrial space and affect human activities in many aspects, especially causing damage to high-tech infrastructure. It usually takes few hours for a CME to arrive at the Earth after eruption. Therefore, many efforts have been devoted to C…

2020 Solar Physics
SOHO 2
Measuring the mass of the supermassive black hole of the lenticular galaxy NGC 4546
DOI: 10.1093/mnras/staa1398 Bibcode: 2020MNRAS.495.2620R

Ricci, T. V.; Steiner, J. E.

Most galaxies with a well-structured bulge host a supermassive black hole (SMBH) in their centre. Stellar kinematics models applied to adaptive optics (AO) assisted integral field unit observations are well-suited to measure the SMBH mass (MBH) and also the total mass-to-light ratio [(M/L)TOT] and possible anisotropies in the…

2020 Monthly Notices of the Royal Astronomical Society
eHST 2