Search Publications

A New Identity Card for the Bulge Globular Cluster NGC 6440 from Resolved Star Counts
DOI: 10.3847/1538-4357/abf938 Bibcode: 2021ApJ...913..137P

Vesperini, Enrico; Pallanca, Cristina; Dalessandro, Emanuele +6 more

We present a new identity card for the cluster NGC 6440 in the Galactic Bulge. We have used a combination of high-resolution Hubble Space Telescope images, wide-field ground-based observations performed with the ESO-FORS2, and the public survey catalog Pan-STARRS to determine the gravitational center, projected density profile, and structural para…

2021 The Astrophysical Journal
Gaia eHST 23
Solar prominence diagnostics from non-LTE modelling of Mg II h&k line profiles
DOI: 10.1051/0004-6361/202140907 Bibcode: 2021A&A...653A...5P

Barczynski, K.; Schmieder, B.; Labrosse, N. +1 more


Aims: We investigate a new method to for obtaining the plasma parameters of solar prominences observed in the Mg II h&k spectral lines by comparing line profiles from the IRIS satellite to a bank of profiles computed with a one-dimensional non-local thermodynamic equilibrium (non-LTE) radiative transfer code.
Methods: Using a grid of…

2021 Astronomy and Astrophysics
Hinode IRIS 23
Ultra-short-period Planets in K2. III. Neighbors are Common with 13 New Multiplanet Systems and 10 Newly Validated Planets in Campaigns 0-8 and 10
DOI: 10.3847/PSJ/ac0ea0 Bibcode: 2021PSJ.....2..152A

Cochran, William D.; Endl, Michael; Howell, Steve B. +14 more

Using the EVEREST photometry pipeline, we have identified 74 candidate ultra-short-period planets (USPs; orbital period P < 1 day) in the first half of the K2 data (Campaigns 0-8 and 10). Of these, 33 candidates have not previously been reported. A systematic search for additional transiting planets found 13 new multiplanet systems containing a…

2021 The Planetary Science Journal
Gaia 23
The surface brightness-colour relations based on eclipsing binary stars and calibrated with Gaia EDR3
DOI: 10.1051/0004-6361/202140571 Bibcode: 2021A&A...649A.109G

Kervella, P.; Anderson, R. I.; Maxted, P. F. L. +23 more


Aims: The surface brightness-colour relation (SBCR) is a basic tool for establishing precise and accurate distances within the Local Group. Detached eclipsing binary stars with accurately determined radii and trigonometric parallaxes allow calibration of the SBCRs with unprecedented accuracy.
Methods: We analysed four nearby eclipsing bi…

2021 Astronomy and Astrophysics
Gaia 23
The Stars Kepler Missed: Investigating the Kepler Target Selection Function Using Gaia DR2
DOI: 10.3847/1538-3881/abee1d Bibcode: 2021AJ....161..231W

Huber, Daniel; Berger, Travis A.; Wolniewicz, Linnea M.

The Kepler Mission revolutionized exoplanet science and stellar astrophysics by obtaining highly precise photometry of over 200,000 stars over 4 yr. A critical piece of information to exploit Kepler data is its selection function, since all targets had to be selected from a sample of half a million stars on the Kepler CCDs using limited informatio…

2021 The Astronomical Journal
Gaia 23
First Phase Space Portrait of a Hierarchical Stellar Structure in the Milky Way
DOI: 10.3847/1538-4357/abda43 Bibcode: 2021ApJ...909...90D

Dalessandro, Emanuele; Saracino, S.; Bellazzini, M. +10 more

We present the first detailed observational picture of a possible ongoing massive cluster hierarchical assembly in the Galactic disk as revealed by the analysis of the stellar full phase space (3D positions and kinematics and spectro-photometric properties) of an extended area (6° diameter) surrounding the well-known h and χ Persei double stellar …

2021 The Astrophysical Journal
Gaia 23
First near-relativistic solar electron events observed by EPD onboard Solar Orbiter
DOI: 10.1051/0004-6361/202039883 Bibcode: 2021A&A...656L...3G

Fedorov, A.; Kulkarni, S. R.; Lario, D. +61 more

Context. Solar Orbiter, launched in February 2020, started its cruise phase in June 2020, in coincidence with its first perihelion at 0.51 au from the Sun. The in situ instruments onboard, including the Energetic Particle Detector (EPD), operate continuously during the cruise phase enabling the observation of solar energetic particles.
Aims: …

2021 Astronomy and Astrophysics
SOHO SolarOrbiter 23
GW190814 follow-up with the optical telescope MeerLICHT
DOI: 10.1051/0004-6361/202040231 Bibcode: 2021A&A...649A..72D

Vreeswijk, P. M.; Groot, P. J.; Bloemen, S. +8 more

Context. The Advanced LIGO and Virgo gravitational wave observatories detected a signal on 2019 August 14 during their third observing run, named GW190814. A large number of electromagnetic facilities conducted follow-up campaigns in the search for a possible counterpart to the gravitational wave event, which was made especially promising given th…

2021 Astronomy and Astrophysics
Gaia 22
The M-dwarf Ultraviolet Spectroscopic Sample. I. Determining Stellar Parameters for Field Stars
DOI: 10.3847/1538-4357/ac0aea Bibcode: 2021ApJ...918...40P

France, Kevin; Youngblood, Allison; Pineda, J. Sebastian

Accurate stellar properties are essential for precise stellar astrophysics and exoplanetary science. In the M-dwarf regime, much effort has gone into defining empirical relations that can use readily accessible observables to assess physical stellar properties. Often, these relations for the quantity of interest are cast as a nonlinear function of…

2021 The Astrophysical Journal
eHST 22
Inspecting the Cepheid parallax of pulsation using Gaia EDR3 parallaxes. Projection factor and period-luminosity and period-radius relations
DOI: 10.1051/0004-6361/202141680 Bibcode: 2021A&A...656A.102T

Kervella, P.; Trahin, B.; Mérand, A. +5 more

Context. As primary anchors of the distance scale, Cepheid stars play a crucial role in our understanding of the distance scale of the Universe because of their period-luminosity relation. Determining precise and consistent parameters (radius, temperature, color excess, and projection factor) of Cepheid pulsating stars is therefore very important.…

2021 Astronomy and Astrophysics
Gaia 22