Search Publications

The discovery of two new benchmark brown dwarfs with precise dynamical masses at the stellar-substellar boundary
DOI: 10.1051/0004-6361/202347906 Bibcode: 2024A&A...684A..88R

Ségransan, D.; Udry, S.; Forveille, T. +7 more


Aims: Measuring dynamical masses of substellar companions is a powerful tool for testing models of mass-luminosity-age relations as well as for determining observational features that constrain the boundary between stellar and substellar companions. In order to dynamically constrain the mass of such companions, we use multiple exoplanet measu…

2024 Astronomy and Astrophysics
Gaia Hipparcos 6
Transient Corotating Clumps around Adolescent Low-mass Stars from Four Years of TESS
DOI: 10.3847/1538-3881/ad0c4c Bibcode: 2024AJ....167...38B

Jayaraman, Rahul; Winn, Joshua N.; Bakos, Gáspár Á. +5 more

Complex periodic variables (CPVs) are stars that exhibit highly structured and periodic optical light curves. Previous studies have indicated that these stars are typically disk-free pre-main-sequence M dwarfs with rotation periods ranging from 0.2 to 2 days. To advance our understanding of these enigmatic objects, we conducted a blind search usin…

2024 The Astronomical Journal
Gaia 6
Measuring White Dwarf Variability from Sparsely Sampled Gaia DR3 Multi-epoch Photometry
DOI: 10.3847/1538-4357/ad3e60 Bibcode: 2024ApJ...967..166S

Hermes, J. J.; Farihi, Jay; Heintz, Tyler M. +5 more

White dwarf stars are ubiquitous in the Galaxy, and are essential to understanding stellar evolution. While most white dwarfs are photometrically stable and reliable flux standards, some can be highly variable, which can reveal unique details about the endpoints of low-mass stellar evolution. In this study, we characterize a sample of high-confide…

2024 The Astrophysical Journal
Gaia 6
First spiral arm detection using dynamical mass measurements of the Milky Way disk
DOI: 10.1051/0004-6361/202449199 Bibcode: 2024A&A...686A..70W

Widmark, Axel; Naik, Aneesh P.

We applied the vertical Jeans equation to the Milky Way disk in order to study non-axisymmetric variations in the thin disk surface density. We divided the disk plane into area cells with a 100 pc grid spacing and used four separate subsets of the Gaia DR3 stars, defined by cuts in absolute magnitude, that reach distances up to 3 kpc. The vertical…

2024 Astronomy and Astrophysics
Gaia 6
Magnetic origin of the discrepancy between stellar limb-darkening models and observations
DOI: 10.1038/s41550-024-02252-5 Bibcode: 2024NatAs...8..929K

Solanki, Sami K.; Seager, Sara; Shapiro, Alexander I. +8 more

Stars appear darker at their limbs than at their disk centres because at the limb we are viewing the higher and cooler layers of stellar photospheres. Yet, limb darkening derived from state-of-the-art stellar atmosphere models systematically fails to reproduce recent transiting exoplanet light curves from the Kepler, TESS and JWST telescopes—stell…

2024 Nature Astronomy
JWST 6
JOYS+ study of solid-state 12C/13C isotope ratios in protostellar envelopes: Observations of CO and CO2 ice with the James Webb Space Telescope
DOI: 10.1051/0004-6361/202451794 Bibcode: 2024A&A...692A.163B

van Dishoeck, E. F.; Nazari, P.; Rocha, W. R. M. +12 more

Context. The carbon isotope ratio is a powerful tool for studying the evolution of stellar systems due to its sensitivity to the local chemical environment. Recent detections of CO isotopologs in disks and exoplanet atmospheres revealed a high variability in the isotope abundance, ponting towards significant fractionation in these systems. In orde…

2024 Astronomy and Astrophysics
ISO JWST 6
Discovery of four new EL CVn-type binaries in the Gaia eclipsing binaries
DOI: 10.1016/j.newast.2023.102153 Bibcode: 2024NewA..10702153P

Wang, Kun; Ren, Anbing; Peng, Yuhui

In this paper, we performed a search for EL CVn-type binaries based on the Gaia and TESS data. Through the combination of the Gaia DR3 eclipsing binary catalogue and the Gaia DR3 spectroscopic binary catalogue, we have identified 13 stars exhibiting EL CVn-like characteristics. Among these stars, nine have already been identified as EL CVn binarie…

2024 New Astronomy
Gaia 6
Investigating the orbital evolution of the eccentric HMXB GX 301-2 using long-term X-ray light curves
DOI: 10.1093/mnras/stad3090 Bibcode: 2024MNRAS.527..640M

Paul, Biswajit; Kumar, Manish; Rana, Vikram +1 more

We report the orbital decay rate of the high-mass X-ray binary GX 301-2 from an analysis of its long-term X-ray light curves and pulsed flux histories from CGRO/BATSE, RXTE/ASM, Swift/BAT, Fermi/GBM, and MAXI by timing the pre-periastron flares over a span of almost 30 yr. The time of arrival of the pre-periastron flares exhibits an energy depende…

2024 Monthly Notices of the Royal Astronomical Society
INTEGRAL 6
INTEGRAL/IBIS polarization detection in the hard and soft intermediate states of Swift J1727.8−1613
DOI: 10.1051/0004-6361/202450826 Bibcode: 2024A&A...688L...5B

Rodriguez, J.; Wilms, J.; Laurent, P. +5 more


Aims: Soft γ-ray emission (100 keV-10 MeV) has previously been detected in the hard state of several microquasars. In some sources, this emission was found to be highly polarized and was suggested to be emitted at the base of the jet. Until now, no γ-ray polarization had been found in any other state.
Methods: Using INTEGRAL/IBIS, we stu…

2024 Astronomy and Astrophysics
INTEGRAL 6
TESS Investigation—Demographics of Young Exoplanets (TI-DYE). II. A Second Giant Planet in the 17 Myr System HIP 67522
DOI: 10.3847/2041-8213/ad77d9 Bibcode: 2024ApJ...973L..30B

Vanderburg, Andrew; Collins, Karen A.; Seager, Sara +13 more

The youngest (<50 Myr) planets are vital to understand planet formation and early evolution. The 17 Myr system HIP 67522 is already known to host a giant (≃10R ) planet on a tight orbit. In their discovery paper, Rizzuto et al. reported a tentative single-transit detection of an additional planet in the system using TESS. Here, we r…

2024 The Astrophysical Journal
Gaia 6