exoclock

HD209458b (MEDIUM)

Discovered by: Henry et al. 2000

The Star
Simbad
GAIA
2MASS		 HD 209458
DR2 1779546757669063552
J22031077+1853036
RA 22:03:10.7729 DEC +18:53:03.548
Parallax
20.675 mas		 P.M. RA
29.579 mas/y		 P.M. DEC
-17.89 mas/y
MagV
7.63		 MagR*
7.305		 MagI*
7.006		 MagJ
6.591		 MagH
6.366		 MagK
6.308
MagG
7.509		 MagGBP
7.813		 MagGRP
7.09
*Calculated from GAIA magnitudes.

Ephemeris - Verified True
Kokori et al. 2025
Mid-time
2459407.335822 ± 4.9e-05 BJDTDB
Period
3.52474918 ± 1.2e-07 days
Transit Parameters
Torres et al. 2008
Rp/Rs
0.12086 ± 0.0001		 a/Rs
8.76 +0.04 -0.04
 i
86.71 +0.05 -0.05 deg
e
-		 ω
- deg
DepthR*
18.11 mmag		 Duration*
3.09 hours
*Calculated from the other parameters, using PyLightcurve.
**Adjusted based on the space observations.

Limb Darkening Parameters
Torres et al. 2008
Teff
6065.0 +50.0 -50.0 K
 Log(g)
4.36 +0.01 -0.01 cm/s2
 Fe/H
0.0 +0.05 -0.05 dex
ExoClock Status
Observing Priority MEDIUM
Minimum aperture 5.0"
Total Observations (Recent) 52 (2)
O-C 0.94 ± 0.49 minutes
ExoClock Observations (Recent) 19 (2)
Space Observations (Recent) 8 (0)
ETD Observations (Recent) 9 (0)
Literature Mid-times (Recent) 16 (0)
Kepler Rp/Rs -
TESS Rp/Rs 0.120779 ± 9e-05

HD209458b


ExoClock Observations
Planet
Observation Date		 Observer
Observatory		 Telescope
Camera / Filter / Exp [s]		 O-C
minutes
HD209458b (MEDIUM)
2025-07-10		Miguel Ángel Álava Amat
Sarriguren		Meade SC 8"
Asi 1600 MM / rpr / 120.0		1.03 ± 1.12
HD209458b (MEDIUM)
2025-07-03		Simon Dawes
William James II		Celestron Edge11 HD
Risingcam Monochrome SONY imx571 / Lum / 15.0		3.16 ± 1.18
HD209458b (MEDIUM)
2024-11-01		Paolo Arcangelo Matassa
P:M.P.H.R. Deep Sky (K81)		Ritchey Chretien 40cm-F5.3
CCD ICX453AQ / R / 15.0		-2.23 ± 1.38
HD209458b (MEDIUM)
2024-09-09		Enrique Arce
Vallbona Observatory		Ritchey Chretien
ZWO ASI 294 MM PRO / V / 4.0		0.5 ± 1.58
HD209458b (MEDIUM)
2024-07-12		David Quiles
David Quiles Observatory		Celestron EDGEHD 800
Omegon veTEC 571M / I / 45.0		1.55 ± 0.84
HD209458b (MEDIUM)
2024-07-12		Ian Sharp
PixelSkies		Celestron C11 Edge HD
Starlight Xpress Trius Pro SX694 / R / 10.0		-1.46 ± 1.87
HD209458b (MEDIUM)
2023-11-18		Rafa Barbera
Rafa Barberá		TS OPTICS PHOTON
ASI 533 MM PRO / gpr / 60.0		0.05 ± 0.91
HD209458b (MEDIUM)
2023-07-14		Yves Jongen
Rasteau Observatory		Plane Wave CDK 17"
SBIG STXL 11002 / R / 5.0		-3.67 ± 1.87
HD209458b (MEDIUM)
2022-09-21		Lionel Rousselot
Private observatory Vierzon		Newton 250/1000
ZWO 1600 monochrome / R / 60.0		0.71 ± 1.11
HD209458b (MEDIUM)
2022-07-23		Eric Miny
BLOIS SOLOGNE ASTRONOMIE OBSERVATORY		Newton T305
QSI 683WS / H / 60.0		-0.41 ± 1.58
HD209458b (MEDIUM)
2022-07-23		Matthieu Bachschmidt
Gonachon		Celestron C11
SBIG ST8XME / AstrodonExoPlanet-BB / 10.0		-1.42 ± 1.01
HD209458b (MEDIUM)
2020-10-09		Martin Smith
Heathwood Road		Skywatcher 120mm ED Apochromatic
Atik 414 ex / R / 1.2		-0.56 ± 4.32
HD209458b (MEDIUM)
2020-08-10		Carmelo Falco
GALHassin Robotic Telescope 2 (GRT2)		Giacometti-Fogale RC16
Andor Apogee Aspen CG16M / Lum / 45.0		3.53 ± 0.86
HD209458b (MEDIUM)
2020-08-03		Carmelo Falco
GALHassin Robotic Telescope 2 (GRT2)		Giacometti-Fogale RC16
Andor Apogee Aspen CG16M / Lum / 60.0		-1.08 ± 1.44
HD209458b (MEDIUM)
2018-08-29		Anaël Wünsche
Observatoire des Baronnies Provençales		Astelco
FLIPL230 / AstrodonExoPlanet-BB / 30.0		3.15 ± 1.01
HD209458b (MEDIUM)
2018-08-29		Yves Jongen
Rasteau Observatory		Plane Wave CDK 17"
SBIG STXL 11002 / V / 120.0		0.84 ± 1.58
HD209458b (MEDIUM)
2012-08-18		Ramon Naves
Montcabrer		Meade LX200 12" ACF
Sbig ST8xme / R / 120.0		2.85 ± 0.43
HD209458b (MEDIUM)
2009-10-30		Filip Walter
Stefanik Observatory		Meade SCT
SBIG ST-10XME / Clear / 60.0		-2.76 ± 1.58
HD209458b (MEDIUM)
2008-11-22		Alessandro Marchini
Astronomical Observatory University of Siena		Mak-Cas 0.3m f/5.6
Sbig STL-6303 / R / 120.0		-2.66 ± 2.16

Space Observations
Planet
Observation Date		 Mission O-C
minutes
HD209458b (MEDIUM)
2022-09-28		TESS-0.18 ± 0.13
HD209458b (MEDIUM)
2022-09-25		TESS0.04 ± 0.11
HD209458b (MEDIUM)
2022-09-21		TESS0.13 ± 0.14
HD209458b (MEDIUM)
2022-09-18		TESS-0.24 ± 0.12
HD209458b (MEDIUM)
2022-09-14		TESS0.03 ± 0.16
HD209458b (MEDIUM)
2022-09-11		TESS0.06 ± 0.12
HD209458b (MEDIUM)
2022-09-07		TESS0.2 ± 0.14
HD209458b (MEDIUM)
2022-09-04		TESS-0.02 ± 0.13

ETD Observations
Planet
Observation Date		 Observer(s) ETD link O-C
minutes
HD209458b (MEDIUM)
2018-08-22		Gabriel Murawski1535045428-1.32 ± 0.58
HD209458b (MEDIUM)
2017-10-30		Didier Walliang1514914047-1.42 ± 1.15
HD209458b (MEDIUM)
2013-08-01		Jaroslav Trnka13754711372.96 ± 1.3
HD209458b (MEDIUM)
2013-08-01		Bernd Koch1375789889-0.36 ± 0.72
HD209458b (MEDIUM)
2012-08-18		Ramon Naves13452691222.62 ± 0.58
HD209458b (MEDIUM)
2012-08-18		Fabio Salvaggio13456503230.46 ± 0.72
HD209458b (MEDIUM)
2010-09-06		Ramon Naves1283797732-2.37 ± 0.72
HD209458b (MEDIUM)
2004-07-13		Osamu OHSHIMA1238767553-2.47 ± 1.73
HD209458b (MEDIUM)
2001-10-23		 Devyatkin A.V., Gorshanov D. L.13068416473.82 ± 2.3

Literature Mid-times
Planet
Observation Date		 Reference O-C
minutes
2012-09-25 Deming et al. 2013 0.03 ± 0.26
2005-09-13 Miller-Ricci et al. 2008 -0.36 ± 1.14
2005-09-09 Miller-Ricci et al. 2008 0.28 ± 1.08
2005-09-06 Miller-Ricci et al. 2008 -0.34 ± 0.94
2005-09-02 Miller-Ricci et al. 2008 -0.73 ± 0.89
2005-08-30 Miller-Ricci et al. 2008 -0.73 ± 0.81
2005-08-26 Miller-Ricci et al. 2008 -0.78 ± 0.81
2005-08-23 Miller-Ricci et al. 2008 0.21 ± 0.79
2005-08-19 Miller-Ricci et al. 2008 -0.9 ± 0.89
2005-08-16 Miller-Ricci et al. 2008 1.29 ± 0.76
2005-08-12 Miller-Ricci et al. 2008 -0.03 ± 0.86
2005-08-08 Miller-Ricci et al. 2008 0.99 ± 0.73
2005-08-05 Miller-Ricci et al. 2008 0.94 ± 1.07
2004-08-28 Miller-Ricci et al. 2008 0.27 ± 0.88
2004-08-25 Miller-Ricci et al. 2008 -0.93 ± 0.71
2004-08-17 Miller-Ricci et al. 2008 -1.02 ± 0.98
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