221 citations · 397 across the 8 of their papers we have counts for
8 papers
Luminous and Variable Stars in NGC 2403 and M81
Roberta M. Humphreys, Sarah Stangl, Michael S. Gordon +2
We present the results of spectroscopy and multi-wavelength photometry of luminous and variable star candidates in the nearby spiral galaxies NGC 2403 and M81. We discuss specific…
The Massive Star Population in M101. III. Spectra and Photometry of the Luminous and Variable Stars
Skyler H. Grammer, Roberta M. Humphreys, Jill Gerke
We discuss moderate resolution spectra, multicolor photometry, and light curves of thirty-one of the most luminous stars and variables in the giant spiral M101. The majority are in…
The Massive Star Population in M101. II. Spatial Variations in the Recent Star Formation History
Skyler Grammer, Roberta M. Humphreys
We investigate the star formation history (SFH) as a function of radius in M101 using archival HST/ACS photometry. We derive the SFH from the resolved stellar populations in five 2…
The Massive Star Population in M101. I. The Identification and Spatial Distribution of the Visually Luminous Stars
Skyler Grammer, Roberta M. Humphreys
An increasing number of non-terminal giant eruptions are being observed by modern supernova and transient surveys. But very little is known about the origin of these giant eruption…
Luminous and Variable Stars in M31 and M33. I. The Warm Hypergiants and Post-Red Supergiant Evolution
Roberta M. Humphreys, Kris Davidson, Skyler Grammer +4
The progenitors of Type IIP supernovae have an apparent upper limit to their initial masses of about 20 solar masses, suggesting that the most massive red supergiants evolve to war…
The Unusual Temporal and Spectral Evolution of SN2011ht. II. Peculiar Type IIn or Impostor?
Roberta M. Humphreys, Kris Davidson, Terry J. Jones +5
SN2011ht has been described both as a true supernova and as an impostor. In this paper, we conclude that it does not match some basic expectations for a core-collapse event. We dis…
Mapping the Asymmetric Thick Disk: III. The Kinematics and Interaction with the Galactic Bar
Roberta M. Humphreys, Timothy C. Beers, Juan E. Cabanela +4
In the first two papers of this series, Larsen et al (2010a,b) describe our faint CCD survey in the inner Galaxy and map the over-density of Thick Disk stars in Quadrant I (Q1) to…
Light Curve Templates and Galactic Distribution of RR Lyrae Stars from Sloan Digital Sky Survey Stripe 82
Branimir Sesar, Zeljko Ivezic, Skyler H. Grammer +14
We present an improved analysis of halo substructure traced by RR Lyrae stars in the SDSS stripe 82 region. With the addition of SDSS-II data, a revised selection method based on n…