253 citations · 1.4k across the 47 of their papers we have counts for
49 papers
An Orbit for a Massive Wolf-Rayet Binary in the LMC: An Example of Binary Evolution
Breelyn Cocke, Philip Massey, Nidia I. Morrell +6
Wolf-Rayet (WR) stars are helium-burning, evolved massive stars which have had most of their hydrogen-rich outer layers removed either through stellar winds and/or binary stripping…
The Stellar Content of NGC~3603 Revisited: Is the IMF Top Heavy?
Philip Massey, Nidia I. Morrell, Kathryn F. Neugent +3
Studies of the resolved stellar populations of young massive clusters have shown that the slope of the initial mass function appears to be the same everywhere, with no dependence o…
A New Determination of the Mass of NGC 3603-A1: the Most Massive Binary Known?
Philip Massey, Sarah Bodansky, Laura R. Penny +2
The star NGC 3603-A1 has long been known to be a very massive binary, consisting of a pair of O2-3If*/WN5-6 stars, which show Wolf-Rayet-like emission due to their luminosities bei…
The Nature of a Recently Discovered Wolf-Rayet Binary: Archetype of Stripping?
Philip Massey, Kathryn F. Neugent, Nidia I. Morrell +2
LMCe055-1 was recently discovered in a survey for WRs in the Large Magellanic Cloud, and classified as a WN4/O4, a lower excitation version of the WN3/O3 class discovered as part o…
Binary Yellow Supergiants in the Magellanic Clouds I: Photometric Candidate Identification
Anna J. G. O'Grady, Maria R. Drout, Kathryn F. Neugent +3
Recent works have constrained the binary fraction of evolved populations of massive stars in local galaxies such as red supergiants and Wolf-Rayet stars, but the binary fraction of…
Physical Properties of 5,000 Cool LMC Supergiants with Gaia XP Spectra: A Detailed Portrait of the Upper HR Diagram Hints at Missing Supernova Progenitors
Trevor Z. Dorn-Wallenstein, Kathryn F. Neugent, Emily M. Levesque
Characterizing the physical properties of cool supergiants allows us to probe the final stages of a massive star's evolution before it undergoes core collapse. Despite their import…
Where do stars explode in the ISM? -- The distribution of dense gas around evolved massive stars in M33
Sumit K. Sarbadhicary, Jordan Wagner, Eric W. Koch +27
The effect of supernovae (SNe) on star-formation in the interstellar medium (ISM) depends sensitively on where SNe explode with respect to ISM clouds. Observationally, SN ISM envir…
Newly Discovered Wolf-Rayet Stars in M31
Kathryn F. Neugent, Philip Massey
The evolved massive star populations of the Local Group galaxies are generally thought to be well-understood. However, recent work suggested that the Wolf-Rayet (WR) content of M31…
Constraints on the Binarity of the WN3/O3 Class of Wolf-Rayet Stars
Philip Massey, Kathryn F. Neugent, Nidia I. Morrell
The WN3/O3 Wolf-Rayet (WR) stars were discovered as part of our survey for WRs in the Magellanic Clouds. The WN3/O3s show the emission lines of a high-excitation WN star and the ab…
A Multiwavelength Study of the Massive Colliding Wind Binary WR 20a: A Possible Progenitor for Fast-Spinning LIGO Binary Black Hole Mergers
Grace M. Olivier, Laura A. Lopez, Katie Auchettl +7
WR 20a is the most massive close-in binary known in our Galaxy. It is composed of two 80 M Wolf-Rayet stars with a short period of 3.7 days in the open cl…
A Survey for C II Emission-Line Stars in the Large Magellanic Cloud. II. Final Results and the Origin of C II Emission in [WC] Spectra
Bruce Margon, Nidia Morrell, Philip Massey +2
We present the final results of an imaging and spectroscopic search for stars in the Large Magellanic Cloud (LMC) with C II 7231, 7236 emission lines. The goal is to identify and s…
The Time-Averaged Mass-Loss Rates of Red Supergiants As Revealed by their Luminosity Functions in M31 and M33
Philip Massey, Kathryn F. Neugent, Sylvia Ekstrom +2
Mass-loss in red supergiants (RSGs) is generally recognized to be episodic, but mass-loss prescriptions fail to reflect this. Evolutionary models show that the total amount of mass…
Cool, Luminous, and Highly Variable Stars in the Magellanic Clouds. II: Spectroscopic and Environmental Analysis of Thorne-Żytkow Object and Super-AGB Star Candidates
Anna J. G. O'Grady, Maria R. Drout, B. M. Gaensler +9
In previous work we identified a population of 38 cool and luminous variable stars in the Magellanic Clouds and examined 11 in detail in order to classify them as either Thorne-Żyt…
The Properties of Fast Yellow Pulsating Supergiants: FYPS Point the Way to Missing Red Supergiants
Trevor Z. Dorn-Wallenstein, Emily M. Levesque, James R. A. Davenport +3
Fast yellow pulsating supergiants (FYPS) are a recently-discovered class of evolved massive pulsator. As candidate post-red supergiant objects, and one of the few classes of pulsat…
WO-Type Wolf-Rayet Stars: the Last Hurrah of Massive Star Evolution
Erin Aadland, Philip Massey, D. John Hillier +3
Are WO-type Wolf Rayet (WR) stars in the final stage of massive star evolution before core-collapse? Although WC- and WO-type WRs have very similar spectra, WOs show a much stronge…
Locating Red Supergiants in the Galaxy NGC 6822
Tzvetelina A. Dimitrova, Kathryn F. Neugent, Philip Massey +1
Using archival near-IR photometry, we identify 51 of the K-band brightest red supergiants (RSGs) in NGC 6822 and compare their physical properties with stellar evolutionary model p…
Testing Evolutionary Models with Red Supergiant and Wolf-Rayet Populations
Philip Massey, Kathryn F. Neugent, Trevor Z. Dorn-Wallenstein +3
Despite the many successes that modern massive star evolutionary theory has enjoyed, reproducing the apparent trend in the relative number of red supergiants (RSGs) and Wolf-Rayet…
The Red Supergiant Binary Fraction as a Function of Metallicity in M31 and M33
Kathryn F. Neugent
Recent work measuring the binary fraction of evolved red supergiants (RSGs) in the Magellanic Clouds points to a value between 15-30%, with the majority of the companions being un-…
The Red Supergiant Content of M31 and M33
Philip Massey, Kathryn F. Neugent, Emily M. Levesque +2
We identify red supergiants (RSGs) in our spiral neighbors M31 and M33 using near-IR (NIR) photometry complete to a luminosity limit of log L/Lo=4.0. Our archival survey data cover…
Short Term Variability of Evolved Massive Stars with TESS II: A New Class of Cool, Pulsating Supergiants
Trevor Z. Dorn-Wallenstein, Emily M. Levesque, Kathryn F. Neugent +3
Massive stars briefly pass through the yellow supergiant (YSG) phase as they evolve redward across the HR diagram and expand into red supergiants (RSGs). Higher-mass stars pass thr…
The Red Supergiant Binary Fraction of the Large Magellanic Cloud
Kathryn F. Neugent, Emily M. Levesque, Philip Massey +2
The binary fraction of unevolved massive stars is thought to be 70-100% but there are few observational constraints on the binary fraction of the evolved version of a subset of the…
A Survey for C II Emission-Line Stars in the Large Magellanic Cloud
Bruce Margon, Philip Massey, Kathryn F. Neugent +1
We present a narrow-band imaging survey of the Large Magellanic Cloud, designed to isolate the C II 7231, 7236 emission lines in objects as faint as . Th…
The Luminosity Function of Red Supergiants in M31
Kathryn F. Neugent, Philip Massey, Cyril Georgy +5
The mass-loss rates of red supergiant stars (RSGs) are poorly constrained by direct measurements, and yet the subsequent evolution of these stars depends critically on how much mas…
The Wolf-Rayet Content of the Galaxies of the Local Group and Beyond
Kathryn F. Neugent, Philip Massey
Wolf-Rayet stars (WRs) represent the end of a massive star's life as it is about to turn into a supernova. Obtaining complete samples of such stars across a large range of metallic…