Thuban

Thuban (Bayer designation: Alpha Draconis or α Dra) is a star in the constellation of Draco. It is located at about 303 light-years away from Earth. It is well

Thuban
Alpha Draconis (Thuban) in the night sky.

Thuban (Bayer designation: Alpha Draconis or α Dra) is a star in the constellation of Draco. It is located at about 303 light-years away from Earth. It is well known because it was the pole star about 3,900 years ago, when the Earth's north pole pointed close to it.[1][2]

It is a white to blue-white giant star with about 3.2 times the Sun's mass and 4.9 times its radius.[3] It shines about 240 times brighter and has a surface temperature of about 10,225 Kelvin. Thuban is also a binary star. It has a smaller companion star that orbits every 51 days.[4] The companion star has a radius of 2.326 times and a mass of about 2.431 times.[3]

References

  1. ↑ Lawrence, Pete (3 April 2024). "Thuban, the star that was once Earth's North Star". BBC Sky at Night Magazine. Our Media Ltd. Retrieved 2026-06-29.
  2. ↑ Kaler, James B. "THUBAN (Alpha Draconis)". Stars. University of Illinois. Retrieved 2026-06-29.
  3. ↑ 3.0 3.1 Pavlovski, K.; Hummel, C. A.; Tkachenko, A. (2022). "Dynamical parallax, physical parameters, and evolutionary status of the components of the bright eclipsing binary α Draconis". Astronomy & Astrophysics. 658: A92. arXiv:2111.03887. Bibcode:2022A&A...658A..92P. doi:10.1051/0004-6361/202142292.
  4. ↑ "SIMBAD Astronomical Database – Alpha Draconis". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2026-06-29.

Content Disclaimer

Informasi ini disarikan dari Wikipedia dan disajikan kembali untuk tujuan edukasi. Konten tersedia di bawah lisensi CC BY-SA 3.0. Kami tidak bertanggung jawab atas ketidakakuratan data yang bersumber dari kontribusi publik tersebut.

  1. The information displayed on this website is sourced in part or in whole from Wikipedia and has been adapted for the purpose of restating it. We strive to provide accurate and relevant information, however:
  2. There is no guarantee of absolute accuracy. Wikipedia is an open, collaborative project that can be edited by anyone, so information is subject to change.
  3. It is not intended to constitute professional advice. The content displayed is for informational and educational purposes only. For important decisions (e.g., medical, legal, or financial), please consult a professional.
  4. Content copyright. Wikipedia is licensed under the Creative Commons Attribution-ShareAlike License (CC BY-SA). This means that content may be reused with appropriate attribution and shared under a similar license.
  5. Responsible use. Any risk arising from the use of information from this website is entirely the responsibility of the user.