TEPCat: KELT-21

This page summarises the information held within TEPCat for the transiting planetary system KELT-21. Please see here for descriptions of the quantities given below.

Discovery and basic observable quantities:
Quantity	Value	Unit
Reference of discovery paper	2018AJ....155..100J
Date of discovery paper	2017 / 12 / 12	y / m / d
Data/telescope used for discovery	KELT
Right ascension	20 19 12.00	h m s
Declination	+32 34 51.8	d m s
Right ascension (decimal)	304.80000	degrees
Declination (decimal)	32.58106	degrees
V-band apparent magnitude	10.48	mag
K-band apparent magnitude	10.09	mag
Transit duration	0.17106 ( 4.1054 )	day hour
Transit depth	1.1	%
Time of mid-transit	2459055.352380 ± 0.000086	HJD or BJD
Orbital period	3.6127640 ± 0.0000031	days
Reference for orbital ephemeris	2022MNRAS.513.2822G

Physical properties from the most recent detailed study:
Quantity	Value	Unit
Stellar effective temperature	7598 +81 −84	K
Stellar metal abundance ([Fe/H] or [M/H])	−0.405 +0.032 −0.033	dex
Stellar mass	1.458 +0.029 −0.028	Msun
Stellar radius	1.638 ± 0.034	Rsun
Stellar logarithmic surface gravity	4.173 +0.015 −0.014	c.g.s.
Stellar mean density	0.332 +0.018 −0.017 ( 0.468 +0.025 −0.024 )	ρsun g cm^-3
Orbital eccentricity	0.0
Orbital semimajor axis	0.05224 +0.00035 −0.00034	AU
Planetary mass	0.0 +3.9 −0.0 ( 0 +1239 −0 )	Mjup Mearth
Planetary radius	1.610 ± 0.034 ( 18.05 ± 0.38 )	Rjup Rearth
Planetary surface gravity	0.0 +38.9 −0.0 0000000000000000000000000000000000000000000000000 +0000000000000000000000000000000000000000000000000 −**0000000000000000000000000000000000000000000000000	m/s2 log(cgs)
Planetary mean density	0.0 +0.93 −0.0 ( 0.0 +1.2 −0.0 )	ρjup g cm^-3
Planetary equilibrium temperature	2051 +29 −30	K
Reference of detailed study	2022MNRAS.513.2822G

Entries in the catalogue of orbital obliquity measurements:
Reference	λ (degrees)
Johnson et al. (2018)	−5.6 + 1.7 - 1.9

Page generated on 2026/01/29 John Southworth (Keele University, UK)