Search Publications
Protostellar and Protoplanetary Disk Masses in the Serpens Region
Law, Charles J.; Williams, Jonathan P.; Ricci, Luca +4 more
We present the results from an Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm continuum and 12CO (J = 2 - 1) line survey spread over 10 deg2 in the Serpens star-forming region of 320 young stellar objects, 302 of which are likely members of Serpens (16 Class I, 35 flat-spectrum, 235 Class II, and 16 Class III). Fr…
The Diverse Shapes of Dwarf Planet and Large KBO Phase Curves Observed from New Horizons
Buratti, Bonnie J.; Singer, Kelsi N.; Stern, S. Alan +15 more
Observing dwarf planets and other large Kuiper Belt objects (KBOs) from vantage points between 8 and 47 au from the Sun, NASA's New Horizons spacecraft has found diversity in the shapes of their solar phase curves. Here we extend solar phase angle coverage of dwarf planets (136199) Eris, (136472) Makemake, and (136108) Haumea; large KBOs (28978) I…
Can we reveal the core-chemical composition of ultra-massive white dwarfs through their magnetic fields?
Córsico, Alejandro H.; Rebassa-Mansergas, Alberto; Althaus, Leandro G. +5 more
Ultra-massive white dwarfs ($1.05\, \rm M_\odot \lesssim M_{WD}$) are particularly interesting objects that allow us to study extreme astrophysical phenomena such as type Ia supernovae explosions and merger events. Traditionally, ultra-massive white dwarfs are thought to harbour oxygen-neon (ONe) cores. However, recent theoretical studies and new …
60 Candidate High-velocity Stars Originating from the Sagittarius Dwarf Spheroidal Galaxy in Gaia EDR3
Shi, Jianrong; Ma, Jun; Du, Cuihua +3 more
Using proper motions from Gaia Early Data Release 3 (Gaia EDR3) and radial velocities from several surveys, we identify 60 candidate high-velocity stars with a total velocity greater than 75% of the escape velocity that probably originated from the Sagittarius dwarf spheroidal galaxy (Sgr) by orbital analysis. Sgr's gravity has little effect on th…
Theoretical analysis of surface brightness-colour relations for late-type stars using MARCS model atmospheres
Plez, B.; Nardetto, N.; Mourard, D. +1 more
Context. Surface brightness-colour relations (SBCRs) are largely used for general studies in stellar astrophysics and for determining extragalactic distances. Based on a careful selection of stars and a homogeneous methodology, it has been recently shown that the SBCR for late-type stars depends on the spectral type and luminosity class.
Aims…
GJ 3929: High-precision Photometric and Doppler Characterization of an Exo-Venus and Its Hot, Mini-Neptune-mass Companion
Cochran, William D.; Endl, Michael; Mahadevan, Suvrath +31 more
We detail the follow-up and characterization of a transiting exo-Venus identified by TESS, GJ 3929b (TOI-2013b), and its nontransiting companion planet, GJ 3929c (TOI-2013c). GJ 3929b is an Earth-sized exoplanet in its star's Venus zone (P b = 2.616272 ± 0.000005 days; S b = ${17.3}_{-0.7}^{+0.8}$ S ⊕) orbiting …
Mapping the Pressure-dependent Day-Night Temperature Contrast of a Strongly Irradiated Atmosphere with HST Spectroscopic Phase Curve
Mayorga, L. C.; Apai, Dániel; Marley, Mark +6 more
Many brown dwarfs are on ultrashort-period and tidally locked orbits around white dwarf hosts. Because of these small orbital separations, the brown dwarfs are irradiated at levels similar to hot Jupiters. Yet, they are easier to observe than hot Jupiters because white dwarfs are fainter than main-sequence stars at near-infrared wavelengths. Irrad…
On the Variation in the Volumetric Evolution of CMEs from the Inner to Outer Corona
Pant, Vaibhav; Patel, Ritesh; Majumdar, Satabdwa
Some of the major challenges faced in understanding the early evolution of coronal mass ejections (CMEs) are due to the limited observations in the inner corona (<3 R ⊙) and the plane-of-sky measurements. In this work, we have thus extended the application of the Graduated Cylindrical Shell (GCS) model to inner coronal observations f…
The peculiar chemical abundance of the transitional millisecond pulsar PSR J1023+0038 - Li enhancement
Breton, R. P.; Kennedy, M. R.; Mata Sánchez, D. +3 more
Using high-resolution optical spectroscopy we determine the chemical abundance of the secondary star in the binary millisecond pulsar PSR J1023+0038. We measure a metallicity of [Fe/H] = 0.48 ± 0.04 which is higher than the Solar value and in general find that the element abundances are different compared to the secondary stars in X-ray binaries a…
The Fractality and Size Distributions of Astrophysical Self-Organized Criticality Systems
Aschwanden, Markus J.
The statistics of nonlinear processes in avalanching systems, based on the self-organized criticality (SOC) concept of Bak et al. (1988), predicts power-law-like size (or occurrence frequency) distribution functions. Following up on previous work, we define a standard SOC model in terms of six assumptions: (i) area fractality, (ii) volume fractali…