XO-4 explained

XO-4 is a star located approximately 863 light-years away from Earth in the Lynx constellation. It has a magnitude of about 11 and cannot be seen with the naked eye but is visible through a small telescope. A search for a binary companion star using adaptive optics at MMT Observatory was negative.

The star XO-4 is named Koit. The name was selected in the NameExoWorlds campaign by Estonia, during the 100th anniversary of the IAU. Koit is Estonian for dawn, and was named for a character in a folk tale written by Friedrich Robert Faehlmann.^{[1] [2] [3]}

Planetary system

One known exoplanet, XO-4b, which is classified as a hot jupiter, orbits XO-4. This exoplanet was discovered in 2008 by the XO Telescope project using the transit method. It has been named Hämarik, meaning dusk, and referring to a character from the same Faehlmann story featuring Koit.^[4]

External links

• Web site: XO-4. Exoplanets. 2009-04-28. 2016-03-03. https://web.archive.org/web/20160303233148/http://media4.obspm.fr/exoplanets/base/etoile.php?nom=XO-4. dead.

Notes and References

1. Web site: Approved names. NameExoworlds. en. 2020-01-02.
2. Web site: International Astronomical Union IAU. www.iau.org. 2020-01-02.
3. Web site: Estonia has been assigned its own star and planet. Estonian World. 20 January 2020. en. 2020-01-20.
4. Web site: Estonia has been assigned its own star and planet. Estonian World. 20 January 2020. en. 2020-01-20.