ARCSAT ID NUMBER: AS04

DESCRIPTIVE TITLE: Stellar Environments of the Nearest Red Dwarfs

PI: Michele Silverstein (GSU)

OBSERVER(S): Michele Silverstein (GSU), Todd Henry (GSU) and Tiffany
Pewett (GSU)

UNCERTIFIED/UNTRAINED OBSERVERS:

COLLABORATORS: Wei-Chun Jao (GSU) and Jen Winters (GSU)

CONTACT INFORMATION: (PI/OBSERVER email/phone)
silverstein@astro.gsu.edu (404-413-6024), thenry@astro.gsu.edu
(404-413-6054)

TIME REQUESTED:

1. NOVEMBER 10 - NOVEMBER 16
2. JANUARY 26 - FEBRUARY 1
3. NOVEMBER 3 - NOVEMBER 9


One week is requested to observe ~100 stars, some of which will be
observed more than once to measure consistency between nights, and
eventually, observing runs.  Photometric standard stars will be
interspersed between science stars.  Any Moon phase is ok.

INSTRUMENT: SurveyCam

FILTERS: VRI

COMMENTS: In Q3, we attempted to use a total of 17 nights on ARCSAT
with SurveyCam under proposal AS09.  Our first run in July
lasted 10 nights, during which we had 1 photometric night useful for
our primary science.  We got some test data for a backup program on 4
additional pieces of non-photometric nights.  We then lost an entire
7-night run in September to bad weather (we opened long enough for ONE
image!), leaving for our Q3 scorecard: 1 good night, 4 partial nights,
and 12 wipeouts in 17 nights.

BRIEF SCIENCE JUSTIFICATION:  (restrict yourself to 1-2 paragraphs)

As part of the PI's thesis, we wish to gather high-quality VRI
photometry of red dwarf stars within 25 pc.  These data will be part
of a comprehensive search for substellar companions and circumstellar
disks around roughly 3000 red dwarfs within 25 pc.  The optical data
from this program are needed to evaluate the spectral energy
distributions (SEDs) of the stars, and will be used in tandem with
2MASS and WISE photometry to extend the SEDs to mid-infrared
wavelengths.  Many red dwarf members of the nearby star sample in the
northern hemisphere lack accurate parallaxes --- the proposed
observations will provide the photometry required to make distance
estimates good to 15% using the techniques in Henry et al. (2004).

In a 7-night run, we will target ~100 stars with magnitudes 8-16 to
map the parameter space of objects that can be effectively observed
with ARCSAT+SurveyCam and continue our survey of red dwarfs in the
solar neighborhood.  Stars will be observed twice each to test
repeatability.  Non-photometric conditions will be used to measure
magnitude differences in VRI, gather differential photometry, and to
check separations and position angles of binaries, astrometry that is
useful for the RECONS 25 Parsec Database currently being built as part
of our survey of the solar neighborhood (www.recons.org).