Beta Canis Minoris facts for kids
 Position of Beta Canis Minoris |
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| Observation data Epoch J2000 Equinox J2000 |
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|---|---|
| Constellation | Canis Minor |
| Right ascension | 07h 27m 09.04174s |
| Declination | +08° 17′ 21.5368″ |
| Apparent magnitude (V) | 2.84–2.92 |
| Characteristics | |
| Spectral type | B8 Ve |
| U−B color index | −0.28 |
| B−V color index | −0.09 |
| Variable type | γ Cas + SPBe |
| Astrometry | |
| Radial velocity (Rv) | +22 km/s |
| Proper motion (μ) | RA: −59.375 ± 1.708 mas/yr Dec.: −35.010 ± 1.368 mas/yr |
| Parallax (π) | 20.3535 ± 1.2220 mas |
| Distance | 160 ± 10 ly (49 ± 3 pc) |
| Absolute magnitude (MV) | −0.59 |
| Details | |
| Mass | 3.5 M☉ |
| Radius | 3.5 R☉ |
| Luminosity | 195 L☉ |
| Surface gravity (log g) | 3.51 cgs |
| Temperature | 11,772 K |
| Rotational velocity (v sin i) | 210 km/s |
| Age | 160+20 −60 Myr |
| Other designations | |
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Gomeisa, Algomeyla, Gomelza, 3 Canis Minoris, BD+08°1774, FK5 285, HD 58715, HIP 36188, HR 2845, IRAS 07244+0823, SAO 115456
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| Database references | |
| SIMBAD | data |
Beta Canis Minoris (also called Gomeisa) is a bright star in the constellation of Canis Minor. It is easy to spot in the night sky because it is close to the even brighter star Procyon.
Contents
What is Gomeisa?
Gomeisa is a star that is about 160 light-years away from Earth. It is much bigger and hotter than our Sun. You can see it without a telescope because it is quite bright.
How Gomeisa Got Its Name
The name Gomeisa comes from an old Arabic phrase. It means "the bleary-eyed woman." This name was given because of how it looked in the sky.
In 2016, a group called the International Astronomical Union (IAU) officially approved the name Gomeisa for this star. They work to give proper names to stars.
In Chinese, Gomeisa is part of an asterism called Nán Hé, or "South River." This group of stars includes Gomeisa, Procyon, and Epsilon Canis Minoris. Gomeisa itself is known as Nán Hé èr, meaning "the Second Star of South River."
Gomeisa's Star Type and Features
Gomeisa is a type of star known as a B8 Ve star. This means it is a B-type star, which are very hot and shine with a blue-white light. Its surface temperature is around 11,772 degrees Celsius (21,222 degrees Fahrenheit).
The "Ve" part of its classification means it is a Be star. Be stars are special because they have a thin, flat disk of gas around them. This gas is ejected from the star itself. This hot, gassy disk around Gomeisa is about three times wider than the star.
Gomeisa is also a main sequence star. This means it is still in the main part of its life, creating energy by turning hydrogen into helium in its core. It has about 3.5 times the Sun's mass.
How Fast Does Gomeisa Spin?
Gomeisa spins very quickly! It rotates at least 210 kilometers (130 miles) per second at its equator. This fast spin might cause the star to flatten a bit at its poles. It completes one full spin in about a day.
Does Gomeisa Change?
Yes, Gomeisa's brightness changes a little bit over time. It is known as a Gamma Cassiopeiae variable star. This means its brightness can vary, though not by a huge amount.
It also belongs to a group called slowly pulsating B-type (SPB) stars. This means its brightness changes in a regular pattern due to waves moving through the star. These changes are very small, but they can be measured by special telescopes.
Could Gomeisa Have a Companion?
Scientists think that Gomeisa might have another star orbiting it very closely. This possible companion star would be much smaller, about 42% the mass of our Sun. If this is true, it would be a rare type of star system. The companion star might be a subdwarf O star, which is a very hot and small star.
See also
In Spanish: Gomeisa para niños
