Publications (10)
DA white dwarfs observed in LAMOST pilot survey
Yue-Yang Zhang, Li-Cai Deng, Chao Liu +14
A total of objects from LAMOST pilot survey have been publicly released. In this work, we present a catalog of DA white dwarfs from the entire pilot survey. We outlin…
New Findings for the Blue Plume Stars in the Canis Major Over-Density
W. Lee Powell, Ronald Wilhelm, Kenneth Carrell +1
We obtained new UBV photometry and spectroscopy of Blue Plume (BP) stars in fields near the center of the Canis Major Over-Density (CMa). We combined analysis of the color-color di…
Numerical Simulation of a possible origin of the positive radial metallicity gradient of the thick disk
Awat Rahimi, Kenneth Carrell, Daisuke Kawata
We analyze the radial and vertical metallicity and [alpha/Fe] gradients of the disk stars of a disk galaxy simulated in a fully cosmological setting with the chemodynamical galaxy…
The Changing Lightcurve of the Double-Mode RR Lyrae Variable Star V338 Boo
Kenneth Carrell, Ronald Wilhelm, Faith Olsen +3
We present an analysis of the lightcurve extracted from Transiting Exoplanet Survey Satellite Full Frame Images of the double-mode RR Lyrae V338 Boo. We find that the fundamental m…
Red Clump Stars in the Sagittarius Tidal Streams
Kenneth Carrell, Ronald Wilhelm, Yuqin Chen
We have probed a section (l ~ 150, b ~ -60) of the trailing tidal arm of the Sagittarius dwarf spheroidal galaxy by identifying a sample of Red Clump stream stars. Red Clump stars…
Caught in the Act: Observations of the Double-mode RR Lyrae V338 Boo During the Disappearance of a Pulsation Mode
Kenneth Carrell, Ronald Wilhelm, Andrew Tom +13
New results on the behavior of the double-mode RR Lyrae V338 Boo are presented. The Transiting Exoplanet Survey Satellite (TESS) observed this star again in 2022, and an observing…
rrlfe: Software for Generating and Applying Metallicity Calibrations for RR Lyrae Variable Stars Across a Wide Range of Phases and Temperatures
Eckhart Spalding, Ronald Wilhelm, Nathan De Lee +7
RR Lyrae stars play a central role in tracing phase-space structures within the Milky Way because they are easy to identify, are relatively luminous, and are found in large numbers…
A resonant feature near the Perseus arm revealed by red clump stars
Chao Liu, Xiangxiang Xue, Min Fang +4
We investigate the extinction together with the radial velocity dispersion and distribution of red clump stars in the anti-center direction using spectra obtained with Hectospec on…
Modulation of the Blazhko Cycle in LS Her
Ronald Wilhelm, Kenneth Carrell, Hannah H. Means +8
We present analysis of the RR Lyrae star, LS Her and confirm the previously reported modulation to its Blazhko cycles. We performed Fourier analysis on two sectors (Sector 24 & 25)…
Metallicity Gradients of Thick Disk Dwarf Stars
Kenneth Carrell, Yuqin Chen, Gang Zhao
We examine the metallicity distribution of the Galactic thick disk using F, G, and K dwarf stars selected from the Sloan Digital Sky Survey, Data Release 8. Using the large sample…