Definition
OGLE-TR-113 is a faint, late‑type main‑sequence star located in the direction of the Galactic bulge that was identified as a candidate host of a transiting exoplanet by the Optical Gravitational Lensing Experiment (OGLE) survey.
Overview
The star was revealed in the OGLE‑III planetary transit search, which monitored millions of stars for periodic dimming indicative of planetary companions. Follow‑up spectroscopy confirmed the presence of a hot‑Jupiter‑type exoplanet, designated OGLE‑TR‑113b, making the system one of the earliest confirmed transiting exoplanets discovered via ground‑based photometry. The discovery was published in 2003 (Konacki et al., Nature 2003).
Etymology / Origin
The designation “OGLE‑TR‑113” derives from the survey that discovered it:
- OGLE – Optical Gravitational Lensing Experiment, a long‑term microlensing and variability survey conducted at the Las Campanas Observatory.
- TR – “Transit,” indicating that the object was identified through periodic transit‑like light‑curve features.
- 113 – the sequential identifier assigned to the 113th transit candidate reported by the OGLE team.
Characteristics
- Coordinates (J2000): Right Ascension ≈ 10 h 52 m 27.9 s, Declination ≈ –61° 40′ 59″.
- Apparent magnitude: V ≈ 14.4 mag; the star is not visible to the naked eye.
- Spectral type: Late‑type dwarf, classified as K V (cooler than the Sun).
- Stellar mass and radius: Approximately 0.78 ± 0.03 M☉ and 0.77 ± 0.02 R☉, respectively, as inferred from spectroscopic analysis and stellar evolution models.
- Metallicity: Near‑solar ([Fe/H] ≈ 0.0 dex), a property typical of many planet‑hosting stars.
- Distance: Roughly 1.5 kpc from the Sun, though exact parallax measurements are uncertain due to the star’s faintness.
Planetary companion (OGLE‑TR‑113b)
- Orbit: Circular orbit with a period of 1.432 days, placing it extremely close to its host star.
- Mass: ≈ 1.08 ± 0.07 M_Jup (Jupiter masses).
- Radius: ≈ 1.08 ± 0.07 R_Jup.
- Classification: Hot Jupiter, characterized by a high equilibrium temperature and inflated radius relative to isolated gas giants.
Related Topics
- Optical Gravitational Lensing Experiment (OGLE) – the survey responsible for the discovery of many microlensing events and transiting exoplanet candidates.
- Transit photometry – the observational technique used to detect periodic dips in stellar brightness caused by planets crossing the stellar disk.
- Hot Jupiters – a class of gas giant exoplanets with very short orbital periods (typically < 10 days).
- OGLE‑TR‑113b – the confirmed exoplanet orbiting OGLE‑TR‑113, frequently cited in studies of planetary formation and atmospheric characterization.
- Exoplanet detection methods – broader context including radial‑velocity, direct imaging, and microlensing techniques.
All data presented are drawn from peer‑reviewed astronomical literature and catalogues up to 2024.