The Yellow and Red Supergiants of M33

Abstract

Yellow and red supergiants are evolved massive stars whose numbers and locations on the HR diagram can provide a stringent test for models of massive star evolution. Previous studies have found large discrepancies between the relative number of yellow supergiants observed as a function of mass and those predicted by evolutionary models, while a disagreement between the predicted and observed locations of red supergiants on the HR diagram was only recently resolved. Here we extend these studies by examining the yellow and red supergiant populations of M33. Unfortunately, identifying these stars is difficult as this portion of the color-magnitude diagram is heavily contaminated by foreground dwarfs. We identify the red supergiants through a combination of radial velocities and a two-color surface gravity discriminant and, after re-characterizing the rotation curve of M33 with our newly selected red supergiants, we identify the yellow supergiants through a combination of radial velocities and the strength of the OI $\lambda$7774 triplet. We examine ~1300 spectra in total and identify 121 yellow supergiants (a sample which is unbiased in luminosity above log(L/L\odot) ~ 4.8) and 189 red supergiants. After placing these objects on the HR diagram, we find that the latest generation of Geneva evolutionary tracks show excellent agreement with the observed locations of our red and yellow supergiants, the observed relative number of yellow supergiants with mass and the observed red supergiant upper mass limit. These models therefore represent a drastic improvement over previous generations.

Accepted for publication in the Astrophysical Journal

References in corpus (14)

• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The effect of massive binaries on stellar populations and supernova progenitors
• A Survey of Local Group Galaxies Currently Forming Stars. I. UBVRI Photometry of Stars in M31 and M33
• The Effective Temperatures and Physical Properties of Magellanic Cloud Red Supergiants: The Effects of Metallicity
• The M33 Metallicity Project: Resolving the Abundance Gradient Discrepancies in M33
• Yellow supergiants as supernova progenitors: an indication of strong mass loss for red supergiants?
• Metallicity and Alpha-Element Abundance Measurement in Red Giant Stars from Medium Resolution Spectra
• The metallicity gradient of M 33: chemical abundances of HII regions
• Yellow and Red Supergiants in the Large Magellanic Cloud
• Molecules and dust production in the Magellanic Clouds
• The WR population predicted by massive single star and by massive binary evolution
• Late-Type Red Supergiants: Too Cool for the Magellanic Clouds?
• A FUSE Survey of the Rotation Rates of Very Massive Stars in the Small and Large Magellanic Clouds
• Deep CFHT Photometric Survey of the Entire M33 Galaxy I: Catalogue of 36000 Variable Point Sources

Cited by in corpus (66)

• MESA Isochrones and Stellar Tracks (MIST). I: Solar-Scaled Models
• Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars
• Binary Population and Spectral Synthesis Version 2.1: construction, observational verification and new results
• The First Data Release (DR1) of the LAMOST general survey
• The LAMOST Stellar Parameter Pipeline at Peking University --- LSP3
• The Effects of Stellar Rotation. I. Impact on the Ionizing Spectra and Integrated Properties of Stellar Populations
• SN2023ixf in Messier 101: A Variable Red Supergiant as the Progenitor Candidate to a Type II Supernova
• On the Social Traits of Luminous Blue Variables
• Betelgeuse Just Isn't That Cool: Effective Temperature Alone Cannot Explain the Recent Dimming of Betelgeuse
• Numerical Simulations of Convective 3-Dimensional Red Supergiant Envelopes
• Luminous Type II Short-Plateau Supernovae 2006Y, 2006ai, and 2016egz: A Transitional Class from Stripped Massive Red Supergiants
• Luminous and Variable Stars in M31 and M33. I. The Warm Hypergiants and Post-Red Supergiant Evolution
• An LTE effective temperature scale for red supergiants in the Magellanic clouds
• A Spectroscopic Survey of Massive Stars in M31 and M33
• The UK Infrared Telescope M33 monitoring project. III. Feedback from dusty stellar winds in the central square kiloparsec
• Luminous and Variable Stars in M31 and M33. II. Luminous Blue Variables, Candidate LBVs, Fe II Emission Line Stars, and Other Supergiants
• Luminous and Variable Stars in M31 and M33. III. The Yellow and Red Supergiants and Post-Red Supergiant Evolution
• JWST's PEARLS: Mothra, a new kaiju star at z=2.091 extremely magnified by MACS0416, and implications for dark matter models
• The excess of cool supergiants from contemporary stellar evolution models defies the metallicity-independent Humphreys-Davidson limit
• The yellow hypergiant HR 5171 A: Resolving a massive interacting binary in the common envelope phase
• Massive Stars in the Galaxies of the Local Group
• The Red Supergiant Content of M31 and M33
• The Luminosity Function of Red Supergiants in M31
• Shedding Light on the Isolation of Luminous Blue Variables
• The Time-Averaged Mass-Loss Rates of Red Supergiants As Revealed by their Luminosity Functions in M31 and M33
• The Dusty and Extremely Red Progenitor of the Type II Supernova 2023ixf in Messier 101
• Red Supergiants in M31 and M33 I. The Complete Sample
• Effects of stellar rotation on star formation rates and comparison to core-collapse supernova rates
• Spectral type, temperature and evolutionary stage in cool supergiants
• The Period-Luminosity Relations of Red Supergiants in M33 and M31
• The Sample of Red Supergiants in Twelve Low-Mass Galaxies of the Local Group
• The isolation of Luminous Blue Variables: On subdividing the sample
• Accurate luminosities from the oxygen 7771-4 A triplet and the fundamental parameters of F-G supergiants
• The Red Supergiant Binary Fraction as a Function of Metallicity in M31 and M33
• The UK Infrared Telescope M33 monitoring project. IV. Variable red giant stars across the galactic disc
• Identification of red supergiants in nearby galaxies with mid-IR photometry
• Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies
• Binary Red Supergiants: A New Method for Detecting B-type Companions
• Effective temperatures of red supergiants estimated from line-depth ratios of iron lines in the YJ bands, 0.97--1.32 micron
• A machine-learning photometric classifier for massive stars in nearby galaxies I. The method
• A spectroscopic study of blue supergiant stars in Local Group spiral galaxies: Andromeda and Triangulum
• On the evolutionary state of massive stars in transition phases in M33
• Red Supergiant Candidates for Multimessenger Monitoring of the Next Galactic Supernova
• Red supergiants and stellar evolution
• Identification of dusty massive stars in star-forming dwarf irregular galaxies in the Local Group with mid-IR photometry
• An atlas of cool supergiants from the Magellanic Clouds and typical interlopers. A guide for the classification of luminous red stars
• Red Supergiants, Yellow Hypergiants, and Post-RSG Evolution
• A Runaway Red Supergiant in M31
• Revisiting the evolved hypergiants in the Magellanic Clouds
• The Evolution of Massive Stars: Bridging the Gap in the Local Group
• Monitoring luminous yellow massive stars in M33: new yellow hypergiant candidates
• Searching for the Next Galactic Luminous Red Nova
• Red Supergiants in the JWST Era. I: Near-IR Photometric Diagnostics
• The Discovery of QSOs Behind M31 and M33
• Red supergiant stars in IC 1613 and metallicity-dependent mixing length in the evolutionary model
• Massive young stellar objects in the Local Group spiral galaxy M33 identified using machine learning
• Betelgeuse and the red supergiants
• Red Supergiants in the Local Group
• The Complex Upper HR Diagram
• Hertzsprung gap stars in nearby galaxies and the Quest for Luminous Red Novae Progenitors
• The Red Supergiant Content of the Local Group
• Red Supergiants in the Milky Way and Nearby Galaxies
• Revisiting the Proper Motions of M31 and M33 Using Massive Supergiant Stars with Gaia DR3
• The Identification of Extreme Asymptotic Giant Branch Stars and Red Supergiants in M33 by 24 μm Variability
• A machine-learning photometric classifier for massive stars in nearby galaxies II. The catalog
• Testing Evolutionary Models with Red Supergiant and Wolf-Rayet Populations