Definition and units of the quantities given in TEPCat

Units and quantities

Physical constants

How many transiting planets are known?

Physical properties of all systems

Symbol	Name	Unit	Notes
Porb	Orbital period	days
e	Orbital eccentricity	-	These numbers are inhomogeneous: see 2011MNRAS.414.1278P. If an upper limit is available then the eccentricity will be given as 0.0 with the upper limit as the upper errorbar.
a	Orbital semimajor axis	AU
Teff	Effective temperature of the star	Kelvin
[Fe/H]	Metal abundance of the star	Logarithmic relative to the Sun	I adopt [M/H] where a specific [Fe/H] is not available
M*	Mass of the star	Msun
R*	Radius of the star	Rsun
logg	Surface gravity of the star	logarithmic in c.g.s. units
ρ*	Density of the star	ρsun
Mp	Mass of the planet	Mjup	Set to 0.0 if only an upper limit is known. The upper limit is then given as the upper errorbar.
Rp	Radius of the planet	Rjup
gp	Surface gravity of the planet	m/s2
ρp	Density of the planet	ρjup	Set to 0.0 if only an upper limit to the mass of the planet is known. The upper limit is then given as the upper errorbar.
Teq	Equilibrium temperature of the planet	Kelvin	These numbers are inhomogeneous as different albedo and heat redistribution parameters are used by different people

Homogeneous Studies quantities

Symbol	Name	Unit	Notes
Teff	Effective temperature of the star	Kelvin
[M/H]	Metal abundance of the star	Logarithmic relative to the Sun	I adopt [M/H] where a specific [Fe/H] is not available
K	Orbital velocity amplitude of the star	m/s
i	Orbital inclination	degrees	i = 90 degrees indicates a system where the orbit is edge-on as seen from Earth
r*	Fractional radius of the star (R*/a)	-
rp	Fractional radius of the planet (Rp/a)	-
M*	Mass of the star	Msun
R*	Radius of the star	Rsun
logg	Surface gravity of the star	logarithmic in c.g.s. units
ρ*	Density of the star	ρsun
a	Orbital semimajor axis	AU
Mp	Mass of the planet	Mjup
Rp	Radius of the planet	Rjup
gp	Surface gravity of the planet	m/s2
ρp	Density of the planet	ρjup
Teq	Equilibrium temperature of the planet	Kelvin	In the case of no albedo (A=0) and no heat redistribution (f=0)
Θ	Safronov number	-	Ratio of the escape velocity to the orbital velocity of the planet

Basic observable quantities

Symbol	Name	Unit	Notes
Type	"TEP" for a transiting planet and "BD" for a transiting brown dwarf
RA	Right ascension of the target	hours minutes seconds	J2000 epoch
Dec	Declination of the target	±degrees minutes seconds	J2000 epoch
V	V-band apparent magnitude	mag
K	K-band apparent magnitude	mag	Usually 2MASS Ks magnitude when available
τ(4-1)	Full duration of a transit	days
ΔF/F	Depth of a transit	percent	This quantity varies slightly with wavelength due to limb darkening and light emitted from the planet
T0	Reference time of mid-transit	HJD or BJD	Time at which the midpoint of one particular transit occurred
Porb	Orbital period	days

Rossiter-McLaughlin effect

Symbol	Name	Unit	Notes
Teff	Effective temperature of the star	Kelvin
λ	Sky-projected angle between the axes of the planet's orbit and the star's spin	degrees	Some studies measure the angle β instead. The two quantities are simply related by: λ = −β
ψ	True angle between the axes of the planet's orbit and the star's spin	degrees	ψ ≥ \|λ\|

Last modified: 2016/03/10 John Southworth (Keele University, UK)