| The Star | |||||
|---|---|---|---|---|---|
| Simbad GAIA 2MASS |
XO-4 DR2 990291507088739072 J07213317+5816051 |
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| RA | 07:21:33.1602 | DEC | +58:16:05.111 | ||
| Parallax 3.639 mas |
P.M. RA -16.989 mas/y |
P.M. DEC 5.31 mas/y |
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| MagV 10.81 |
MagR* 10.322 |
MagI* 10.239 |
MagJ 9.667 |
MagH 9.476 |
MagK 9.406 |
| MagG 10.513 |
MagGBP 10.778 |
MagGRP 10.117 |
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| *Calculated from GAIA magnitudes. | |||||
Ephemeris
- Verified 
|
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|---|---|---|---|---|---|
| Kokori et al. 2025 | |||||
| Mid-time 2458153.11815 ± 0.00018 BJDTDB |
|||||
| Period 4.12506593 ± 3.8e-07 days |
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| Transit Parameters | |||||
| Narita et al. 2010 | |||||
| Rp/Rs 0.0881 ± 0.0007 |
a/Rs 7.68 +0.11 -0.11 |
i 88.8 +0.6 -0.6 deg |
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| e - |
ω - deg |
||||
| DepthR* 10.15 mmag |
Duration* 4.43 hours |
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|
*Calculated from the other parameters, using PyLightcurve.
**Adjusted based on the space observations. |
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| Limb Darkening Parameters | |||||
| McCullough et al. 2008 | |||||
| Teff 6397.0 +70.0 -70.0 K |
Log(g) 4.18 +0.07 -0.07 cm/s2 |
Fe/H -0.04 +0.03 -0.03 dex |
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| ExoClock Status | |||||
|---|---|---|---|---|---|
| Observing Priority | LOW | ||||
| Minimum aperture | 5.0" | ||||
| Total Observations (Recent) | 63 (6) | ||||
| O-C | -1.56 ± 0.54 minutes | ||||
| ExoClock Observations (Recent) | 31 (6) | ||||
| Space Observations (Recent) | 15 (0) | ||||
| ETD Observations (Recent) | 1 (0) | ||||
| Literature Mid-times (Recent) | 16 (0) | ||||
| Kepler Rp/Rs | - | ||||
| TESS Rp/Rs | 0.08627 ± 0.00024 | ||||
ExoClock Observations |
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| Planet Observation Date |
Observer Observatory |
Telescope Camera / Filter / Exp [s] |
O-C minutes |
|
|---|---|---|---|---|
| XO-4b (LOW) 2026-01-24 | Üllar Kivila Looga Observatory | TS Optics (GSO) 8" RC Omegon veTEC 585 C / Clear / 90.0 | -3.16 ± 1.73 | |
| XO-4b (LOW) 2025-12-27 | Vojtěch Školník Hvězdárna v Úpici | SW N200/800 MI C2-7000A / Clear / 60.0 | 1.1 ± 1.73 | |
| XO-4b (LOW) 2025-12-27 | Tommaso Dittadi TD-TRO | Ritchey-Chretien Moravian G2-1600 / R / 90.0 | -1.49 ± 1.58 | |
| XO-4b (LOW) 2025-04-02 | Üllar Kivila Looga Observatory | TS Optics (GSO) 8" RC Omegon veTEC 585 C / Clear / 120.0 | 0.36 ± 1.73 | |
| XO-4b (LOW) 2025-03-05 | Simon Dawes William James II | Celestron Edge11 HD Risingcam Monochrome SONY imx571 / Lum / 85.0 | 2.61 ± 2.45 | |
| XO-4b (LOW) 2025-03-05 | Yves Jongen Rasteau Observatory | Plane Wave CDK 17" SBIG STXL 11002 / R / 60.0 | -8.91 ± 2.16 | |
| XO-4b (LOW) 2025-01-02 | Leon Bewersdorff Starfront Observatories | Corrected Ritchey-Chrétien QHY268M / AstrodonExoPlanet-BB / 60.0 | -2.3 ± 2.3 | |
| XO-4b (LOW) 2024-12-24 | Claudio Lopresti Claudio Lopresti | Mak-Newton CCD Sbig ST10xme / I / 240.0 | 1.34 ± 2.45 | |
| XO-4b (LOW) 2024-11-30 | Deborah Smith Complejo Astronomico Los Coloraos, Gorafe | C9.25 QHY9 / R / 50.0 | -3.56 ± 1.73 | |
| XO-4b (LOW) 2024-10-24 | Martin Crow Burnham Observatory | Celestron C9.25 SX694 mono / R / 45.0 | -0.11 ± 2.74 | |
| XO-4b (LOW) 2024-10-24 | Michael Nezel Celle Observatory | CDK 14 QHY 268M / R / 90.0 | -1.55 ± 1.35 | |
| XO-4b (LOW) 2024-04-04 | Giovanni Calapai Home Astronomical Observatory | Celestron 11 Schmidt-Cassegrain Atik 314L+ / Clear / 90.0 | -1.65 ± 2.16 | |
| XO-4b (LOW) 2023-03-05 | Paolo Arcangelo Matassa P:M.P.H.R. Deep Sky (K81) | Ritchey Chretien 40cm-F5.3 CCD ICX453AQ / Lum / 30.0 | -0.46 ± 1.87 | |
| XO-4b (LOW) 2023-03-05 | Eric Miny BLOIS SOLOGNE ASTRONOMIE OBSERVATORY | Newton T305 QSI 683WS / Lum / 60.0 | -4.2 ± 2.45 | |
| XO-4b (LOW) 2023-01-31 | Marco Stefanini Osservatorio Aldebaran | Ritchey-Chretien Altair Astro Atik 4000 LE / Lum / 250.0 | -1.43 ± 4.03 | |
| XO-4b (LOW) 2023-01-03 | Pieter Vuylsteke TheGardenToTheSkyFacility | TS ONTC 25cm f4.7 QHY 268M / rpr / 60.0 | -1.91 ± 1.73 | |
| XO-4b (LOW) 2022-03-07 | Mark Salisbury POST | Orion Optics ODK SBIG ST-10 XME / R / 100.0 | 0.7 ± 1.15 | |
| XO-4b (LOW) 2022-02-11 | Kevin Johnson Holbrook Observatory | Meade LX10 EMC Atik 383L+ / R / 50.0 | 1.84 ± 2.3 | |
| XO-4b (LOW) 2022-02-02 | Paolo Arcangelo Matassa P:M.P.H.R. Deep Sky (K81) | Ritchey Chretien 40cm-F5.3 CCD ICX453AQ / Lum / 90.0 | 3.04 ± 2.16 | |
| XO-4b (LOW) 2021-12-31 | Fran Campos Puig d'Agulles Observtory | RC14" on EQ8 German mount SBIG ST-8XME / R / 60.0 | 6.68 ± 1.3 | |
| XO-4b (LOW) 2021-01-11 | Yves Jongen Rasteau Observatory | Plane Wave CDK 17" SBIG STXL 11002 / R / 120.0 | -0.28 ± 1.58 | |
| XO-4b (LOW) 2020-11-06 | Adrian Jones Private Observatory (I64) | Meade ACF 30cm QSI 583 / R / 30.0 | -1.78 ± 4.32 | |
| XO-4b (LOW) 2020-11-02 | Alberto Tomatis Alto-Observatory | RC STL 6303 / Lum / 60.0 | 4.22 ± 3.17 | |
| XO-4b (LOW) 2020-10-28 | Martin Crow Burnham Observatory | Celestron C9.25 SX694 mono / R / 15.0 | 1.29 ± 4.32 | |
| XO-4b (LOW) 2020-03-11 | Nikolaos Paschalis Nunki Observatory | Officina Stellare RILA 400 SBIG STXL 11002 / R / 60.0 | 3.29 ± 2.02 | |
| XO-4b (LOW) 2020-03-11 | Alessandro Nastasi Galhassin Robotic Telescope 1 (GRT1) | Officina Stellare RiLa 400 FLI ProLine 16803 / R / 45.0 | 2.57 ± 2.16 | |
| XO-4b (LOW) 2020-03-11 | Danilo Sedita Osservatorio Sedita Castrofilippo | RC GSO 14" Moravian G2-1600 / R / 30.0 | 1.28 ± 1.44 | |
| XO-4b (LOW) 2020-02-07 | Mauro Caló Cavallino | RC SBIG ST10 / R / 60.0 | -1.28 ± 4.32 | |
| XO-4b (LOW) 2020-02-03 | Tõnis Eenmäe Tartu Observatory | Planewave CDK 12.5 Apogee Alta U42 / R / 30.0 | 2.85 ± 0.86 | |
| XO-4b (LOW) 2020-01-05 | Pere Guerra Observatori Astronòmic Albanyà | 16" Meade ACF F8 Moravian G4-9000 / I / 120.0 | 1.36 ± 1.87 | |
| XO-4b (LOW) 2020-01-05 | Yves Jongen Rasteau Observatory | Plane Wave CDK 17" SBIG STXL 11002 / V / 120.0 | -0.52 ± 1.73 | |
Space Observations |
||||
| Planet Observation Date |
Mission | O-C minutes |
||
| XO-4b (LOW) 2023-01-15 | TESS | 1.31 ± 0.82 | ||
| XO-4b (LOW) 2023-01-11 | TESS | -1.07 ± 0.76 | ||
| XO-4b (LOW) 2023-01-03 | TESS | 0.22 ± 0.79 | ||
| XO-4b (LOW) 2022-12-29 | TESS | -2.89 ± 0.95 | ||
| XO-4b (LOW) 2022-01-25 | TESS | 0.1 ± 0.85 | ||
| XO-4b (LOW) 2022-01-21 | TESS | -0.12 ± 0.84 | ||
| XO-4b (LOW) 2022-01-17 | TESS | -0.14 ± 0.79 | ||
| XO-4b (LOW) 2022-01-13 | TESS | -2.84 ± 0.81 | ||
| XO-4b (LOW) 2022-01-09 | TESS | -1.43 ± 0.68 | ||
| XO-4b (LOW) 2022-01-05 | TESS | -1.29 ± 0.71 | ||
| XO-4b (LOW) 2020-01-18 | TESS | -0.11 ± 0.86 | ||
| XO-4b (LOW) 2020-01-14 | TESS | 0.16 ± 0.85 | ||
| XO-4b (LOW) 2020-01-09 | TESS | 0.61 ± 0.82 | ||
| XO-4b (LOW) 2020-01-05 | TESS | 0.31 ± 0.81 | ||
| XO-4b (LOW) 2020-01-01 | TESS | 1.41 ± 0.71 | ||
ETD Observations |
||||
| Planet Observation Date |
Observer(s) | ETD link | O-C minutes |
|
| XO-4b (LOW) 2020-03-16 | Anaël Wünsche | 1584328042 | 1.61 ± 1.87 | |
Literature Mid-times |
||||
| Planet Observation Date |
Reference | O-C minutes |
||
| 2012-01-07 | Villanueva et al. 2016 | 3.05 ± 1.3 | ||
| 2010-03-18 | Villanueva et al. 2016 | 4.71 ± 1.73 | ||
| 2010-02-09 | Narita et al. 2010 | 1.43 ± 0.94 | ||
| 2010-02-09 | Villanueva et al. 2016 | -1.44 ± 1.05 | ||
| 2009-12-05 | Villanueva et al. 2016 | -4.29 ± 2.16 | ||
| 2009-11-10 | Villanueva et al. 2016 | 1.31 ± 1.44 | ||
| 2009-09-05 | Narita et al. 2010 | 3.84 ± 1.58 | ||
| 2009-02-11 | Villanueva et al. 2016 | -2.93 ± 2.74 | ||
| 2009-01-17 | Villanueva et al. 2016 | -2.94 ± 4.03 | ||
| 2009-01-13 | Todorov et al. 2012 | 1.62 ± 0.86 | ||
| 2009-01-09 | Todorov et al. 2012 | -0.59 ± 1.15 | ||
| 2008-12-11 | Todorov et al. 2012 | -3.38 ± 1.01 | ||
| 2008-11-12 | Villanueva et al. 2016 | 3.91 ± 1.73 | ||
| 2008-10-10 | Narita et al. 2010 | 1.34 ± 1.64 | ||
| 2008-10-06 | Narita et al. 2010 | 1.8 ± 1.51 | ||
| 2008-01-20 | McCullough et al. 2008 | -2.22 ± 0.58 | ||