Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

PDF

Physics & Astronomy

Stars: low-mass

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

The Muscles Treasure Survey. I. Motivation And Overview, Kevin France, R. O. Parke Loyd, Allison Youngblood, Alexander Brown, P. Christian Schneider, Suzanne L. Hawley, Cynthia S. Froning, Jeffrey L. Linsky, Aki Roberge, Andrea P. Buccino, James R. A. Davenport, Juan M. Fontenla, Lisa Kaltenegger, Adam F. Kowalski, Pablo J. D. Mauas, Yamila Miguel, Seth Redfield, Sarah Rugheimer, Feng Tian, Mariela C. Vieytes, Lucianne M. Walkowicz, Kolby L. Weisenburger Apr 2016

The Muscles Treasure Survey. I. Motivation And Overview, Kevin France, R. O. Parke Loyd, Allison Youngblood, Alexander Brown, P. Christian Schneider, Suzanne L. Hawley, Cynthia S. Froning, Jeffrey L. Linsky, Aki Roberge, Andrea P. Buccino, James R. A. Davenport, Juan M. Fontenla, Lisa Kaltenegger, Adam F. Kowalski, Pablo J. D. Mauas, Yamila Miguel, Seth Redfield, Sarah Rugheimer, Feng Tian, Mariela C. Vieytes, Lucianne M. Walkowicz, Kolby L. Weisenburger

Physics & Astronomy

Ground- and space-based planet searches employing radial velocity techniques and transit photometry have detected thousands of planet-hosting stars in the Milky Way. With so many planets discovered, the next step toward identifying potentially habitable planets is atmospheric characterization. While the Sun–Earth system provides a good framework for understanding the atmospheric chemistry of Earth-like planets around solar-type stars, the observational and theoretical constraints on the atmospheres of rocky planets in the habitable zones (HZs) around low-mass stars (K and M dwarfs) are relatively few. The chemistry of these atmospheres is controlled by the shape and absolute flux of the stellar spectral …


Detecting Differential Rotation And Starspot Evolution On The M Dwarf Gj 1243 With Kepler, James R. A. Davenport, Leslie Hebb, Suzanne L. Hawley Jun 2015

Detecting Differential Rotation And Starspot Evolution On The M Dwarf Gj 1243 With Kepler, James R. A. Davenport, Leslie Hebb, Suzanne L. Hawley

Physics & Astronomy

We present an analysis of the starspots on the active M4 dwarf GJ 1243, using 4 years of time series photometry from Kepler. A rapid P = 0.592596 ± 0.00021 days rotation period is measured due to the ~2.2% starspot-induced flux modulations in the light curve. We first use a light curve modeling approach, using a Monte Carlo Markov Chain sampler to solve for the longitudes and radii of the two spots within 5 day windows of data. Within each window of time the starspots are assumed to be unchanging. Only a weak constraint on the starspot latitudes can …


Boss Ultracool Dwarfs I: Colors And Magnetic Activity Of M And L Dwarfs, Sarah J. Schmidt, Suzanne L. Hawley, Andrew A. West, John J. Bochanski, James R. A. Davenport, Jian Ge, Doanld P. Schneider Apr 2015

Boss Ultracool Dwarfs I: Colors And Magnetic Activity Of M And L Dwarfs, Sarah J. Schmidt, Suzanne L. Hawley, Andrew A. West, John J. Bochanski, James R. A. Davenport, Jian Ge, Doanld P. Schneider

Physics & Astronomy

We present the colors and activity of ultracool (M7–L8) dwarfs from the Tenth Data Release of the Sloan Digital Sky Survey (SDSS). We combine previous samples of SDSS M and L dwarfs with new data obtained from the Baryon Oscillation Sky Survey (BOSS) to produce the BOSS Ultracool Dwarf (BUD) sample of 11820 M7–L8 dwarfs. By combining SDSS data with photometry from 2MASS and the Wide-field Infrared Sky Explorer (WISE) mission, we present ultracool dwarf colors from to as a function of spectral type, and extend the SDSS–2MASS–WISE color locus to include ultracool dwarfs. The , , …


Kepler Flares Ii: The Temporal Morphology Of White-Light Flares On Gj 1243, James R. A. Davenport, Suzanne L. Hawley, Leslie Hebb, John P. Wisniewski, Adam F. Kowalski, Emily C. Johnson, Michael Malatesta, Jesus Paraza, Marcus Keil, Steven M. Silverberg, Tiffany C. Jansen, Matthew S. Scheffler, Jodi R. Berdis, Daniel M. Larsen, Eric J. Hilton Dec 2014

Kepler Flares Ii: The Temporal Morphology Of White-Light Flares On Gj 1243, James R. A. Davenport, Suzanne L. Hawley, Leslie Hebb, John P. Wisniewski, Adam F. Kowalski, Emily C. Johnson, Michael Malatesta, Jesus Paraza, Marcus Keil, Steven M. Silverberg, Tiffany C. Jansen, Matthew S. Scheffler, Jodi R. Berdis, Daniel M. Larsen, Eric J. Hilton

Physics & Astronomy

We present the largest sample of flares ever compiled for a single M dwarf, the active M4 star GJ 1243. Over 6100 individual flare events, with energies ranging from 1029 to 1033 erg, are found in 11 months of 1 minute cadence data from Kepler. This sample is unique for its completeness and dynamic range. We have developed automated tools for finding flares in short-cadence Kepler light curves, and performed extensive validation and classification of the sample by eye. From this pristine sample of flares we generate a median flare template. This template shows that two exponential …


Multi-Wavelength Characterization Of Stellar Flares On Low-Mass Stars Using Sdss And 2mass Time Domain Surveys, James R. A. Davenport, Andrew C. Becker, Adam F. Kowalski, Suzanne L. Hawley, Sarah J. Schmidt, Eric J. Hilton, Branimir Sesar, Roc Cutri Mar 2012

Multi-Wavelength Characterization Of Stellar Flares On Low-Mass Stars Using Sdss And 2mass Time Domain Surveys, James R. A. Davenport, Andrew C. Becker, Adam F. Kowalski, Suzanne L. Hawley, Sarah J. Schmidt, Eric J. Hilton, Branimir Sesar, Roc Cutri

Physics & Astronomy

We present the first rates of flares from M dwarf stars in both red optical and near-infrared (NIR) filters. We have studied ~50,000 M dwarfs from the Sloan Digital Sky Survey (SDSS) Stripe 82 area and 1321 M dwarfs from the Two Micron All Sky Survey (2MASS) Calibration Scan Point Source Working Database that overlap SDSS imaging fields. We assign photometric spectral types from M0 to M6 using (ri) and (iz) colors for every star in our sample. Stripe 82 stars each have 50-100 epochs of data, while 2MASS Calibration stars have …


Improved Photometric Calibrations For Red Stars Observed With The Sdss Photometric Telescope, James R. A. Davenport, John J. Bochanski, Kevin R. Covey, Suzanne L. Hawley, Andrew A. West, Doanld P. Schneider Nov 2007

Improved Photometric Calibrations For Red Stars Observed With The Sdss Photometric Telescope, James R. A. Davenport, John J. Bochanski, Kevin R. Covey, Suzanne L. Hawley, Andrew A. West, Doanld P. Schneider

Physics & Astronomy

We present a new set of photometric transformations for red stars observed with the Sloan Digital Sky Survey (SDSS) 0.5 m Photometric Telescope (PT) and the SDSS 2.5 m telescope at the Apache Point Observatory in New Mexico. Nightly PT observations of US Naval Observatory standards are used to determine extinction corrections and calibration terms for SDSS 2.5 m photometry. Systematic differences between the PT and native SDSS 2.5 m ugriz photometry require conversions between the two systems which have previously been undefined for the reddest stars. By matching ~43,000 stars observed with both the PT and SDSS 2.5 m, …