Glossary term: Sirius

Description: Sirius, also called the Dog Star or Alpha Canis Majoris, is the star that appears brightest in the night sky to our eyes. It is located at a distance of 8.6 light years from us in the constellation Canis Major near Orion. The bright star that is visible to us is Sirius A, a star of spectral type A. Sirius A has a gravitationally bound companion, Sirius B, which is a white dwarf star that is very faint in visible light but very bright in X-rays. Sirius B is too faint and too close to Sirius A to be seen with the naked eye.

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Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".

Related Media

The bow tie shaped Orion over dry, rocky outcrops. Sirius appears as a bright star between two pillars of rock

Winter Constellations

Caption: Second place in the 2022 IAU OAE Astrophotography Contest, category Time lapses of celestial patterns. Sirius, the brightest star in the night sky, is shown rising, setting and passing by. Sometimes constellations and asterisms are also visible, including Orion, Taurus and the Pleiades. In the first scene, the aforementioned constellations are covered by a semi-transparent golden veil. The next scenes show it rising in a dark blue night sky. In one of the scenes, a planet brightly decorates the faint constellation Pisces. The videos were taken above various landscapes and places of cultural heritage on Earth. Some of them simply show monuments in the desert, while others show palm trees with waving leaves.
Credit: Amirreza Kamkar/IAU OAE

License: CC-BY-4.0 Creative Commons Attribution 4.0 International (CC BY 4.0) icons

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