J/AJ/155/39 Variability properties of TIC sources with KELT (Oelkers+, 2018)
Variability properties of four million sources in the TESS Input Catalog
observed with the Kilodegree Extremely Little Telescope survey.
Oelkers R.J., Rodriguez J.E., Stassun K.G., Pepper J., Somers G., Kafka S.,
Stevens D.J., Beatty T.G., Siverd R.J., Lund M.B., Kuhn R.B., James D.,
Gaudi B.S.
<Astron. J., 155, 39-39 (2018)>
=2018AJ....155...39O 2018AJ....155...39O (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Proper motions ; Parallaxes, trigonometric ;
Photometry, UBV ; Photometry, ugriz ; Photometry, infrared ;
Effective temperatures ; Surveys
Keywords: stars: rotation - stars: variables: general - surveys
Abstract:
The Kilodegree Extremely Little Telescope (KELT) has been surveying
more than 70% of the celestial sphere for nearly a decade. While the
primary science goal of the survey is the discovery of transiting,
large-radii planets around bright host stars, the survey has collected
more than 106 images, with a typical cadence between 10-30 minutes,
for more than four million sources with apparent visual magnitudes in
the approximate range 7<V<13. Here, we provide a catalog of 52741 objects
showing significant large-amplitude fluctuations likely caused by
stellar variability, as well as 62229 objects identified with likely
stellar rotation periods. The detected variability ranges in rms-amplitude
from ∼3 mmag to ∼2.3 mag, and the detected periods range from ∼0.1 to
≳2000 days. We provide variability upper limits for all other
∼4000000 sources. These upper limits are principally a function of
stellar brightness, but we achieve typical 1σ sensitivity on 30 min
timescales down to ∼5 mmag at V∼8, and down to ∼43 mmag at V∼13. We have
matched our catalog to the TESS Input catalog and the AAVSO Variable
Star Index to precipitate the follow-up and classification of each
source. The catalog is maintained as a living database on the Filtergraph
visualization portal at the URL https://filtergraph.com/kelt_vars.
Description:
The KELT-N telescope has been observing from Winer Observatory in Sonoita
Arizona (31°39'56.08" N, Longitude 110°36'06.42" W, elevation
1515.7 m) since 2007. Winer Observatory hosts weather with 60% observable
nights, half of which are determined to be photometric.
The KELT-S telescope has been observing from South African Astronomical
Observatory near Sutherland South Africa (32°22'46" S, 20°38'48" E,
altitude 1768 m) since 2012. The Sutherland site typically experiences
70% observable nights, with 60% of this time considered photometric.
Typical seeing at the site reaches ∼0.92".
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 89 52741 Astrometric Information for KELT Variables
table3.dat 125 52741 Magnitude Information for KELT Variables
table4.dat 111 52741 Variability Information for KELT Variables
table5.dat 76 3873790 Variability Upper Limits for Non-Variable
Sources in the TESS Input Catalog
table6.dat 76 62229 Rotation Information for TIC Dwarf Candidates
--------------------------------------------------------------------------------
See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJ/809/77 : Transiting Exoplanet Survey Satellite (TESS) (Sullivan+, 2015)
http://filtergraph.com/kelt_vars : Filtergraph portal
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
19- 27 I9 --- TIC [358/470926220]? TESS Input Catalog (TIC)
identification
29- 30 I2 h RAh Hour of Right Ascension Primary (J2000)
32- 33 I2 min RAm Minute of Right Ascension Primary (J2000)
35- 36 I2 s RAs Second of Right Ascension Primary (J2000)
38 A1 --- DE- Sign of the Declination of the Primary (J2000)
39- 40 I2 deg DEd Degree of Declination Primary (J2000)
42- 43 I2 arcmin DEm Arcminute of Declination Primary (J2000)
45- 46 I2 arcsec DEs Arcsecond of Declination Primary (J2000)
48- 54 F7.2 mas/yr pmRA [-293.67/273]? Proper motion in Right Ascension
in TIC (pmRA*cosDE) (1)
56- 60 F5.2 mas/yr e_pmRA [0.02/25.5]? Error in pmRA
62- 68 F7.2 mas/yr pmDE [-314.92/222.8]? Proper motion in Declination
in TIC (1)
70- 74 F5.2 mas/yr e_pmDE [0.02/25.5]? Error in pmDE
76- 82 F7.4 mas Plx [0.0023/48.95]? Parallax reported in TIC (1)
84- 89 F6.4 mas e_Plx [0.2086/6.69]? Error in Plx
--------------------------------------------------------------------------------
Note (1): TIC v11/07/17.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
19- 27 I9 --- TIC [358/470926220]? TESS Input Catalog (TIC)
identification
29- 34 F6.3 mag VKmag [5.782/16.365] Zeropointed KELT-V magnitude
36- 41 F6.3 mag Tmag [4.399/20.556]? TESS magnitude from TIC v11/07/17
43- 48 F6.3 mag Bmag [6.39/19.14]? APASS B magnitude
50- 55 F6.3 mag Vmag [6.319/18.056]? APASS V magnitude
57- 62 F6.3 mag gmag [6.935/18.277]? APASS g magnitude
64- 69 F6.3 mag rmag [6.23/17.485]? APASS r magnitude
71- 76 F6.3 mag imag [5.529/16.91]? APASS i magnitude
78- 83 F6.3 mag Jmag [1.001/16]? 2MASS J magnitude
85- 90 F6.3 mag Hmag [-0.105/18.099]? 2MASS H magnitude
92- 97 F6.3 mag Ksmag [-0.598/17.406]? 2MASS Ks magnitude
99-104 F6.3 mag W1mag [-2.201/15.764]? WISE W1 magnitude
106-111 F6.3 mag W2mag [-2.249/17.019]? WISE W2 magnitude
113-118 F6.3 mag W3mag [-3.902/13.622]? WISE W3 magnitude
120-125 F6.3 mag W4mag [-3.964/10.196]? WISE W4 magnitude
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
19- 27 I9 --- TIC [358/470926220]? TESS Input Catalog (TIC)
identification
29- 34 F6.3 mag VKmag [5.782/16.365] Zeropointed KELT-V magnitude
36- 40 F5.3 mag rms [0.003/2.39] rms metric
42- 46 F5.3 mag D90 [0.011/8.03] Δ90 metric (a proxy for
the amplitude of variability)
48- 55 F8.3 --- Js [-114.241/2763.734]? Welch-Stetson J metric
56- 57 A2 --- n_Js [I -I] Note on Js (I for +∞, -I for
-∞)
59- 66 F8.3 --- Ls [-56.923/1390.26]? Welch-Stetson L metric
67- 68 A2 --- n_Ls [I -I] Note on Js (I for +∞, -I for
-∞)
70- 80 F11.6 d Per-LS [0.100064/2488.454102]? Lomb-Scargle period
82- 86 F5.3 --- Pwr [0.1/0.984]? Lomb-Scargle power
88- 93 F6.3 --- Ap [1/99.99]? Lomb-Scargle period significance
95 I1 --- Var [0/1] Variability flag (0=False, 1=True)
97 I1 --- Per [0/1] Periodicity flag (0=False, 1=True)
99 I1 --- MP [0/1] Multi-Periodic flag (0=False, 1=True)
101 I1 --- Alias [0/1]? Alias flag (1)
103 I1 --- Bld [0/1]? Blend flag (1)
105 I1 --- Prx [0/1]? Proximity flag (1)
107 I1 --- Pts [0/1]? Points flag (1)
109 I1 --- Edg [0/1]? Edge flag (1)
111 I1 --- Sgl [0/1]? Single flag (1)
--------------------------------------------------------------------------------
Note (1): While we take care to select objects most likely to be bona fide
variables, the catalog is not free from spurious members. We have created a
set of six catalogs flags designed to educate the reader that a given variable
could be contaminated by common KELT systematics. These catalog flags are
described as:
ALIAS = If at least three of the top five peaks in the Lomb-Scargle power
spectrum are aliases of the sidereal day, lunar month or calendar
year the ALIAS flag is set to 1;
BLEND = If the centroid of a stars was within 5 pix (1.9') of the centroid
of another star brighter by more than 1.5 magnitudes, the BLEND
flag is set to 1;
PROXIMITY = If a candidate variable is within 5 pix (1.9') of another
candidate variable, which is brighter by more than 1.5 magnitudes,
the PROXIMITY flag is set to 1;
POINTS = If the total number of data points for any light curve is less
than N<µN-1σN, where N is the number of data points
in the light curve, µN is the mean number of data points of
all light curves in the E/W orientation, and σN is the
standard deviation of the mean number of data points per field,
the POINTS flag is set to 1;
EDGE = If a star was closer than 200 pixels to the edge of the CCD, the
EDGE flag is set to 1;
SINGLE = If a star has only one light curve (either E or W but not both)
and passed either all variability metrics or all periodicity
requirements, the SINGLE flag is set to 1.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
18 A1 --- m_2MASS [AB] Component designation
20- 28 I9 --- TIC [5/471012756] TESS Input Catalog (TIC)
identification
30- 31 I2 h RAh Hour of Right Ascension Primary (J2000)
33- 34 I2 min RAm Minute of Right Ascension Primary (J2000)
36- 39 F4.1 s RAs Second of Right Ascension Primary (J2000)
41 A1 --- DE- Sign of the Declination of the Primary (J2000)
42- 43 I2 deg DEd Degree of Declination Primary (J2000)
45- 46 I2 arcmin DEm Arcminute of Declination Primary (J2000)
48- 49 I2 arcsec DEs Arcsecond of Declination Primary (J2000)
51- 58 F8.5 mag Tmag [2.905/20.926] TESS magnitude from TIC v11/07/17
60- 64 F5.3 mag rms30m [0/1.638] rms metric in 30 minute exposure
66- 70 F5.3 mag rms2h [0/1.597] rms metric in 2 hour exposure
72- 76 F5.3 mag rms1d [0/1.586] rms metric in 1 day exposure
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS identification (JHHMMSSss+DDMMSSs)
19- 27 I9 --- TIC [34920/471000657] TESS Input Catalog (TIC)
identification
29- 34 F6.3 mag Vmag ? V magnitude from TIC v11/07/17
36- 41 I6 K Teff [2872/31796]? Effective temperature from TIC
v11/07/17
43- 48 F6.3 [cm/s2] log(g) [-6.976/7.501]? Log surface gravity from TIC
v11/07/17
50- 59 F10.6 d Prot [0.505252/50] Rotation period
61- 65 F5.3 --- FAP [0/0.001] False alarm probability
67- 74 F8.3 --- Pwr [15.582/3307.08] Lomb-Scargle power
76 I1 --- Var [0/1] Variability catalog flag (1)
--------------------------------------------------------------------------------
Note (1): The variability flag denotes if the stellar rotation period was also
recovered as part of the variability search.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 21-Sep-2018