GSC 02652-01324
Template:Short description Template:Starbox begin Template:Starbox image Template:Starbox observe Template:Starbox character Template:Starbox astrometry Template:Starbox detail Template:Starbox catalog Template:Starbox reference Template:Starbox end
GSC 02652-01324, also known as V672 Lyrae, is an orange dwarf main sequence star approximately 521 light-years away in the constellation of Lyra (the Lyre).<ref name="Roman1987"/><ref name="Gaia DR3"/> It hosts one known exoplanet, TrES-1b.<ref name="Alonso2004"/>
There is a small, cool companion star at a separation of 13.2 arcseconds, corresponding to 2111 AU.<ref name="Mugrauer2019"/>
Nomenclature
The designation GSC 02652-01324 comes from the Guide Star Catalog.
The star is sometimes called TrES-1,<ref name="NEA"/> in reference to its planet discovered by the Trans-Atlantic Exoplanet Survey (TrES). The discovery paper<ref name="Alonso2004"/> and the SIMBAD database<ref name="Simbad"/> use this designation for the planet itself, but other sources call the star TrES-1<ref name="Baluev2015"/> and the planet TrES-1b,<ref name=Yeung2022/> following the standard exoplanet naming convention.
Since the planet transits the star, the star is classified as a planetary transit variable and has received the variable star designation V672 Lyrae. The transits last a little over an hour, about 4% of the orbital period, and the brightness diminishes by a few hundredths of a magnitude.<ref name="GCVS"/>
Planetary system
In 2004, the exoplanet TrES-1b was found to be orbiting this star by the Trans-Atlantic Exoplanet Survey using the transit method. The planet was detected crossing its parent star using a small Template:Convert telescope. The discovery was confirmed by the Keck Observatory using the radial velocity method, allowing its mass to be determined.<ref name="Alonso2004"/><ref name="Keck press release"/> The planet is a hot Jupiter, with a mass and size similar to those of Jupiter but an orbital period of only three days.
Evidence of a candidate second planet, designated TrES-1c, was found in 2025 by the radial velocity method. If existing, this planet would have a minimum mass about that of Saturn, and an eccentric orbit with a 1,200-day period.<ref name="Hagley2025"/>
An additional planet in the system is suspected due to transit-timing variations (TTVs) of TrES-1b,<ref name=Yeung2022/> but has not been detected.<ref name="Hagley2025"/> For a planet causing the observed TTVs to remain undetected, it would need to have a mass less than ~Template:Jupiter mass and an orbital period less than ~7 days. Other than the TTVs, there is as yet no evidence of such a planet, but the observed TTVs cannot be explained by other known effects.<ref name="Hagley2025"/>
Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:OrbitboxPlanet hypothetical Template:Orbitbox end