J/PASP/131/G5001 New variable stars and eclipsing binaries (Ratzloff+, 2019)
Building the Evryscope: hardware design and performance.
Ratzloff J.K., Law N.M., Fors O., Corbett H.T., Howard W.S., del Ser D.,
Haislip J.
<Publ. Astron. Soc. Pac. 131, g5001 (2019)>
=2019PASP..131g5001R 2019PASP..131g5001R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Binaries, eclipsing
Abstract:
The Evryscope is a telescope array designed to open a new parameter
space in optical astronomy, detecting short-timescale events across
extremely large sky areas simultaneously. The system consists of a 780
MPix 22-camera array with an 8150 sq. deg. field of view, 13'' per
pixel sampling, and the ability to detect objects down to
mg'~=16 in each 2-minute dark-sky exposure. The
Evryscope, covering 18400 sq. deg. with hours of high-cadence
exposure time each night, is designed to find the rare events that
require all-sky monitoring, including transiting exoplanets around
exotic stars like white dwarfs and hot subdwarfs, stellar activity of
all types within our galaxy, nearby supernovae, and other transient
events such as gamma-ray bursts and gravitational-wave electromagnetic
counterparts. The system averages 5000 images per night with ∼300000
sources per image, and to date has taken over 3.0M images, totaling
250 TB of raw data. The resulting light curve database has light
curves for 9.3M targets, averaging 32600 epochs per target through
2018. This paper summarizes the hardware and performance of the
Evryscope, including the lessons learned during telescope design,
electronics design, a procedure for the precision polar alignment of
mounts for Evryscope-like systems, robotic control and operations, and
safety and performance-optimization systems. We measure the on-sky
performance of the Evryscope, discuss its data analysis pipelines, and
present some example variable star and eclipsing binary discoveries
from the telescope. We also discuss new discoveries of very rare
objects including two hot subdwarf eclipsing binaries with late
M-dwarf secondaries (HW Vir systems), two white dwarf/hot subdwarf
short-period binaries, and four hot subdwarf reflection binaries. We
conclude with the status of our transit surveys, M-dwarf flare survey,
and transient detection.
Description:
We present some example Variables and Eclipsing Binary discoveries
from the Evryscope instrument paper. The search was confined in
declinations of +5 to +10, magnitude V between 11.0 and 15.0, and
using the first 6 months of data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 111 45 Variable star discoveries
table6.dat 111 14 Eclipsing binary discoveries
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/336 : AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)
Byte-by-byte Description of file: table4.dat table6.dat
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Bytes Format Units Label Explanations
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1- 22 A22 --- ESID ES ID (EVRJHHMMSS.ss+DDMMSS.s)
25- 31 A7 --- --- [GaiaDR2]
32- 50 I19 --- GaiaDR2 GaiaDR2 source number (source_id)
52- 59 F8.4 deg RAdeg Right ascension (J2000)
61- 66 F6.4 deg DEdeg Declination (J2000)
68- 72 F5.2 mag Vmag V magnitude
74- 78 F5.2 --- RPM ? Reduced proper motion
80- 83 F4.2 mag B-V ? B-V colour index
85- 89 A5 --- Size Star size (ms or giant)
91- 95 A5 --- SpType Spectral type
97-105 F9.4 h Period Period
107-111 F5.3 mag Amp Amplitude of the variability
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Acknowledgements:
Jeff Ratzloff, jeff215(at)live.unc.edu
(End) Jeff Ratzloff [UNC Chapel Hill], Patricia Vannier [CDS] 31-May-2019