Search Publications
Blue Stragglers as Tracers of the Dynamical State of Two Clusters in the Small Magellanic Cloud: NGC 339 and NGC 419
Dalessandro, E.; Massari, D.; Ferraro, F. R. +5 more
The level of central segregation of Blue Straggler stars has proved to be an excellent tracer of the dynamical evolution of old star clusters (the so-called "dynamical clock"), both in the Milky Way and in the Large Magellanic Cloud. The A + parameter, used to measure the Blue Stragglers degree of segregation, has in fact been found to …
Milky Way Zero-point Calibration of the JAGB Method: Using Thermally Pulsing AGB Stars in Galactic Open Clusters
Madore, Barry F.; Freedman, Wendy L.; Lee, Abigail J. +1 more
We present a new calibration of the J-band absolute magnitude of the JAGB method based on thermally pulsing AGB stars that are members of Milky Way open clusters, having distances and reddenings, independently compiled and published by Marigo. A total 17 of these photometrically selected J-Branch AGB stars give M J = -6.40 mag with a …
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…
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…
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 …
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 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…
Unveiling the Nature of SN 2011fh: A Young and Massive Star Gives Rise to a Luminous SN 2009ip-like Event
Kochanek, Christopher S.; Prieto, Jose L.; Fox, Ori D. +6 more
In recent years, many Type IIn supernovae have been found to share striking similarities with the peculiar SN 2009ip, whose true nature is still under debate. Here, we present 10 yr of observations of SN 2011fh, an interacting transient with spectroscopic and photometric similarities to SN 2009ip. SN 2011fh had an M r ~ -16 mag bright…
The Disk-Outflow System around the Rare Young O-type Protostar W42-MME
Dewangan, L. K.; Ojha, D. K.; Mayya, Y. D. +6 more
We present line and continuum observations (resolution ~0.″3-3.″5) made with the Atacama Large Millimeter/submillimeter Array (ALMA), Submillimeter Array, and Very Large Array of a young O-type protostar W42-MME (mass: 19 ± 4 M ⊙). The ALMA 1.35 mm continuum map (resolution ~1″) shows that W42-MME is embedded in one of the cores (i.e., …
On the Origin of the Dichotomy of Stellar Activity Cycles
Corsaro, Enrico; Bonanno, Alfio
The presence of possible correlations between stellar rotation rate Ω and the frequency of the activity cycle ω cyc is still much debated. We implement a new Bayesian classification algorithm based on a simultaneous regression analysis of multiple scaling laws and we demonstrate the existence of two different scalings in the ${\mathrm{l…