ExoClock

The Star
Simbad GAIA 2MASS	KELT-1 DR2 2881784280929695360 J00012691+3923017
RA	00:01:26.9169		DEC	+39:23:01.782
Parallax 3.697 mas		P.M. RA -9.771 mas/y		P.M. DEC -7.679 mas/y
Mag_V 10.63	Mag_R^* 10.391	Mag_I^* 10.028	Mag_J 9.682	Mag_H 9.534	Mag_K 9.437
Mag_G 10.59		Mag_{G_BP} 10.873		Mag_{G_RP} 10.175
^*Calculated from GAIA magnitudes.

Ephemeris - Verified
Kokori et al. 2021
Mid-time 2456981.90516 ± 0.00014 BJD_TDB
Period 1.21749399 ± 1.6e-07 days
Transit Parameters
Beatty et al. 2019
R_p/R_s 0.0771 ± 0.0003	a/R_s 3.69 +0.04 -0.04		i 86.8 +0.8 -0.8 deg
R_p/R_s 0.0771 ± 0.0003	e 0.0013 +0.0005 -0.0005		ω 358.0 +51.0 -51.0 deg
Depth_R^* 7.71 mmag		Duration^* 2.71 hours
^Calculated from the other parameters, using PyLightcurve. ^*Adjusted to produce a duration that matches the observations.
Limb Darkening Parameters
Siverd et al. 2012
T_eff 6518.0 +50.0 -50.0 K	Log(g) 4.23 +0.03 -0.03 cm/s²		Fe/H 0.05 +0.08 -0.08 dex

ExoClock Status
Observing Priority ExoClock Observations (Recent) Space Observations Literature Mid-times ETD Observations O-C minutes		LOW 20 (7) 20 1.1±0.3

ExoClock Observations

Observation Date	Observer Observatory	Telescope Camera / Filter / Exp [s]	O-C minutes
2021-12-21	Manfred Raetz privat observatory Herges-Hallenberg	SCT 280 /1790 (Celestron C11 with reducer) Moravian Instruments G2-1600 / R / 120.0	2.3 ± 0.9
2021-12-21	Mark Salisbury POST	Orion Optics ODK SBIG ST-10 XME / R / 90.0	1.8 ± 1.2
2021-10-28	Paolo Arcangelo Matassa P.M.P.H.R. Deep Sky (K81)	Ritchey Chretien ICX453AQ / R / 90.0	-4.5 ± 5.8
2021-10-25	Taewoo Kim Deokheung Optical Astronomy Observatory	NYSC 1m Telescope FLI PL-16803 or PI SOPHIA-2048B / R / 50.0	2.2 ± 0.7
2021-10-21	Martin Crow Burnham Observatory	Celestron C9.25 SX694 mono / R / 30.0	0.6 ± 2.6
2021-09-12	Yves Jongen Rasteau Observatory	Plane Wave CDK 17" SBIG STXL 11002 / R / 40.0	4.9 ± 1.9
2021-07-28	Taewoo Kim Deokheung Optical Astronomy Observatory	NYSC 1m Telescope FLI PL-16803 or PI SOPHIA-2048B / R / 60.0	0.4 ± 0.7
2020-11-08	Alessandro Nastasi Galhassin Robotic Telescope 1 (GRT1)	Officina Stellare RiLa 400 FLI ProLine 16803 / z' / 90.0	-2.2 ± 3.0	- Data available
2020-11-02	Simon Dawes William James II Observatory	Skywatcher MN190 2 ZWO ASI 1600MM-PRO USB 3.0 Mono Camera / R / 45.0	-1.0 ± 2.6	- Data available
2020-09-13	David Wright Yorick (private observatory)	Ritchey-Chretien QSI 683WSG-8 / R / 85.0	-3.3 ± 2.4	- Data available
2020-08-12	Carmelo Falco GALHassin Robotic Telescope 2 (GRT2)	Giacometti-Fogale RC16 Andor Apogee Aspen CG16M / B / 30.0	-0.2 ± 1.2	- Data available
2020-08-12	Yves Jongen Rasteau Observatory	Plane Wave CDK 17" SBIG STXL 11002 / R / 120.0	-0.3 ± 1.9	- Data available
2020-08-05	Adam Popowicz Observatory Pyskowice	RC12" GSO ASI ZWO 1600 MM / ATIK 11000M / R / 60.0	1.6 ± 3.2	- Data available
2020-07-26	Fabio Mortari Hypatia Observatory	Newton 250mm f/4.9 Sbig ST8-XE / R / 120.0	3.7 ± 1.6	- Data available
2020-07-19	Antonio Marino UAN c/o INAF-Osservatorio Astronomico di Capodimonte, Naples ITALY	MEADE CCD Atik 383L / Clear / 60.0	-3.5 ± 4.3
2020-07-15	Francois Regembal HRTobs	Astrosib RC360 SBIG STX 16803 / Lum / 60.0	0.6 ± 1.6	- Data available
2020-01-10	Dimitrios Deligeorgopoulos Artemis Observatory	GSO RC Atik 16 HR / R / 60.0	4.5 ± 4.3	- Data available
2019-12-30	Martin Crow Burnham Observatory	Celestron C9.25 SX694 mono / R / 60.0	-2.5 ± 1.6	- Data available
2019-08-07	Anaël Wünsche Observatoire des Baronnies Provençales	Astelco FLIPL230 / V / 60.0	-0.4 ± 1.6	- Data available
2015-09-26	Anaël Wünsche Observatoire des Baronnies Provençales	CDK Planewave SBIG STL11K / V / 120.0	2.0 ± 1.6	- Data available

Literature Mid-times

Observation Date	Mid-time	Time format	Reference	O-C minutes
2018-11-05	2458428.2875 ± 0.0011	BJD_TDB	Maciejewski et al. 2018	-0.7 ± 1.6
2018-09-05	2458367.4129 ± 0.0014	BJD_TDB	Maciejewski et al. 2018	-0.6 ± 2.0
2018-01-07	2458126.349 ± 0.00084	BJD_TDB	Maciejewski et al. 2018	-0.7 ± 1.2
2017-11-23	2458081.3019 ± 0.00085	BJD_TDB	Maciejewski et al. 2018	-0.5 ± 1.2
2017-09-30	2458026.5167 ± 0.00073	BJD_TDB	Maciejewski et al. 2018	2.4 ± 1.1
2017-09-23	2458020.42711 ± 0.00054	BJD_TDB	Maciejewski et al. 2018	-0.6 ± 0.8
2017-09-19	2458015.5573 ± 0.00046	BJD_TDB	Maciejewski et al. 2018	-0.4 ± 0.7
2017-08-15	2457981.4677 ± 0.00077	BJD_TDB	Maciejewski et al. 2018	-0.0 ± 1.1
2017-07-25	2457959.5526 ± 0.00054	BJD_TDB	Maciejewski et al. 2018	-0.3 ± 0.8
2015-10-11	2457306.97624 ± 0.00028	BJD_TDB	Beatty et al. 2020	0.3 ± 0.4
2013-10-18	2456583.7843 ± 0.0006	BJD_UTC	Beatty et al. 2017	0.7 ± 0.9
2012-09-11	2456182.0142 ± 0.0023	BJD_TDB	Beatty et al. 2014	3.7 ± 3.3
2012-09-10	2456180.7969 ± 0.0022	BJD_TDB	Beatty et al. 2014	4.0 ± 3.2
2012-01-07	2455933.6432 ± 0.0004	BJD_TDB	Siverd et al. 2012	0.5 ± 0.6
2012-01-01	2455927.55574 ± 0.00041	BJD_TDB	Siverd et al. 2012	0.5 ± 0.6
2011-12-16	2455911.72553 ± 0.00044	BJD_TDB	Siverd et al. 2012	-3.5 ± 0.6
2011-12-13	2455909.29289 ± 0.00028	BJD_TDB	Maciejewski et al. 2018	-0.1 ± 0.4
2011-12-10	2455905.63858 ± 0.00083	BJD_TDB	Siverd et al. 2012	-2.7 ± 1.2
2011-12-04	2455899.55496 ± 0.001	BJD_TDB	Siverd et al. 2012	2.9 ± 1.4
2011-12-04	2455899.55407 ± 0.00043	BJD_TDB	Siverd et al. 2012	1.5 ± 0.6

KELT-1b

Discovered by: Siverd et al. 2012

ExoClock Observations

Literature Mid-times