Virgo’s Brightest Star
Virgo’s brightest star Spica is, in fact, 2 stars
Spica is not an individual star: it is a binary star system, that consists of two stars known as Spica A and Spica B. These stars orbit each other so close that they can’t even be resolved as two stars through a telescope. Also, their mutual gravity distorts them into an oval shape.
Spica A
Spica A is the larger and more massive star of the pair. It is a blue-white giant star that shines with a luminosity over 2,000 times that of our Sun: 80% of the light in the star system comes from Spica A. With a diameter approximately 10 times larger than the Sun, Spica A is an impressive celestial body.
Spica B
Spica B is a smaller and less massive component of the star system. It is a blue-white main-sequence star, meaning it is still in the process of burning hydrogen in its core. Although smaller than Spica A, Spica B is still seven times larger than our Sun.
More facts about Spica
Bright star in the night sky
Spica is the brightest star in the constellation Virgo. Also, it is ranked as the 15th brightest star overall (or 16th, if you count the Sun).
Bright stars in the Orion constellation
With many prominent stars brighter than magnitude 4, Orion is easy to see with the naked eye.
Rigel
- Other names: β Ori, Beta Orionis, HR 1713, HIP 24436
- Type: blue supergiant
- Magnitude: from 0.05 to 0.18
- Name’s origin: “left foot or leg” (Arabic)
- Description: Rigel is the brightest star in Orion and the 7th brightest star in the night sky. It is located at a distance of about 860 light-years from the Solar System.
Betelgeuse
- Other names: α Ori, Alpha Orionis, HR 2061, HIP 27989
- Type: red supergiant
- Magnitude: from 0.0 to 1.6
- Name’s origin: “armpit of the giant” (Arabic)
- Description: Betelgeuse is the second brightest star in Orion and the 10th brightest star in the night sky. It is the nearest red supergiant star to the Earth, located at about 724 light-years from our planet.
Betelgeuse is nearing the end of its life cycle and is expected to explode as a supernova, which could make it one of the brightest objects in the night sky for a time. Read the article to learn more about when we’ll see Betelgeuse going supernova.
Bellatrix
- Other names: γ Ori, Gamma Orionis, HR 1790, HIP 25336
- Type: blue giant
- Magnitude: from 1.59 to 1.64
- Name’s origin: “female warrior” (Latin)
- Description: Bellatrix is the third-brightest star in Orion. Bellatrix is one of the hottest stars you can see with the naked eye: it has a temperature of 21,477°C (for comparison, the Sun is 5,500°C).
Ursa Major stars
Ursa Major brightest stars
The most known Ursa Major stars are the ones that form the Big Dipper: Benetnash (Alkaid), Mizar-Alcor, Alioth, Megrez, Dubhe, Merak, and Phad (Phecda). Mizar-Alcor is a system that contains at least three pairs of stars, but it looks like a single star to the naked eye. The brightest stars in the asterism are Alioth, Dubhe, and Merak.
Alioth — Epsilon Ursae Majoris
Alioth (ε UMa, HIP 62956, HR 4905) is the brightest star in the Great Bear and the 31st brightest in the night sky, shining at a magnitude of 1.8. It is located in the Big Dipper’s handle, closest to the bowl. The star is almost 3 times more massive than our Sun, located more than 82 light-years away from it. It’s also one of the 58 primary stars historically used in celestial navigation. “Alioth” originates from the Arabic “alyat al-hamal,” which means “the sheep’s fat tail.”
Dubhe — Alpha Ursae Majoris
Dubhe (α UMa, HIP 54061, HR 4301) is the second brightest star in Ursa Major, the upper right point of the Big Dipper’s bowl. Its apparent magnitude is 1.8. Dubhe is the spectroscopic binary system where the primary star Dubhe A is an orange giant of around 4.25 solar masses. Along with Alioth, Dubhe is included in the list of the primary navigational stars. The star’s name originates from the Arabic phrase meaning “the back of the Greater Bear.” Dubhe is one of the two Big Dipper’s stars that help to find Polaris.
Merak — Beta Ursae Majoris
Merak (β UMa, HIP 53910, HR 4295) is the fifth brightest star in Ursa Major, the bottom right point of the Big Dipper’s bowl. Along with Dubhe, it serves as “a pointer” to find Polaris. Merak is a bluish-white subgiant star with an apparent magnitude of 2.3. It contains 2.7 solar masses and is located at around 80 light-years from our Sun. The name “Merak” comes from the Arabic “al-maraqq,” meaning “the loins.”
Pollux: the brightest star in Gemini
Named after a Greek myth hero
In Greek mythology, Pollux, also known as Polydeuces, and his twin brother Castor were sons of the Spartan queen Leda. Castor was the mortal son of King Tyndarus, while Pollux was the immortal son of Zeus. The twins were inseparable, and when Castor died, Pollux asked Zeus that the two should share immortality, so Zeus placed them both in the sky as the constellation Gemini. Because of the myth, Castor and Pollux are often referred to as the “twin stars”, although the stars are not related.
Brightest star in Gemini, yet not an Alpha
While studying the stars, you probably noticed that the brightest star in a constellation is usually designated by the Greek letter Alpha. However, in Gemini, the Alpha star is Castor, while Pollux is Beta. This naming system was created by the German astronomer Johann Bayer in 1603. In this system, the stars within a constellation appear to be listed from brightest to dimmest. But back then, astronomers couldn’t accurately measure the brightness of stars, so Bayer sorted them based on their magnitude class (first-magnitude, second-magnitude, etc.). Within each class, the stars were not necessarily arranged by brightness. Also, sometimes Bayer assigned letters to stars based on their position within a constellation, their order of rising, or for historical or mythological reasons.
Hosts a planet
Pollux is known to host a planet in its orbit called Pollux b, or Thestias. This gas giant exoplanet was discovered in 2006. It orbits its parent star at a distance similar to that of Jupiter from our Sun.
Bright star Pollux
Pollux is the brightest star in the constellation Gemini. It can be easily observed in the night sky from December through March. You can locate Pollux by using the Big Dipper, the bright stars in Orion, or stargazing apps like Star Walk 2 and Sky Tonight.
Regulus (Alpha Leonis) – Brightest star of LEO
- Official name: Regulus, Alpha Leonis, Alpha Leo, α Leo
- Alternative names: Cor Leonis, Lion’s Heart, Basiliskos, Qalb al-Asad, Kabeleced, Rex
- Catalog designations: 32 Leonis, HIP 49669, HR 3982, HD 87901, TYC 833-1381-1
- Constellation: Leo
- Star type: class B7 V main-sequence star
- Right ascension: 10 h 08 m 21.2 s
- Declination: +11° 58′ 06.3″
- Apparent magnitude: 1.4
- Mass: 3.8 solar masses
- Luminosity: 316.2 L
- Radius: 4.35 solar radius
- Surface temperature: 12,460 K
- Distance from the Earth: 79.3 light-years
- Rotation period: 16 hours
Regulus star system
Although Regulus appears to be a single star, it’s actually a system of four stars that are organized into two pairs. The first pair, known as Regulus A, consists of the blue main sequence star of the spectral type B8 and a presumed main sequence white dwarf. The blue star is visible to the naked eye, and its partner has never been directly observed. Astronomers predicted its existence using spectroscopic analysis.
If you have a small telescope with at least 50x magnification, you can spot the third star in the Regulus system, called Regulus B. It’s a cool orange dwarf star that belongs to the spectral type K2 V. Regulus B has its own companion, Regulus C, which is a red dwarf of the spectral type M4V. You’ll need a powerful telescope to catch a glimpse of Regulus C.
Where is Regulus in the sky?
Regulus is the 21st brightest star in the sky. It resides within the constellation Leo and is one of the three bright stars making up the Spring Triangle, a recognizable asterism. The star has an apparent magnitude of 1.4, which means it’s easily visible to the naked eye without any telescopes or binoculars.
So, if you’re looking for a new celestial object to explore and show off to your friends, Regulus is a great choice. Now let’s discover how to locate this stunning star in the sky above you.
How to find Leo’s brightest star – the Sickle of Leo
A classic way to find Regulus in the night sky is to look at it in relation to other celestial objects. Regulus is part of the asterism called the Sickle of Leo, which resembles a backward question mark. To locate Regulus, start by searching for the Sickle in the band of the sky where you see the Moon and the planets (near the ecliptic).
If you live in the Northern Hemisphere, you can also use the famous Big Dipper, the asterism of Ursa Major, to locate the star. Draw an imaginary line between the two stars, called Megrez and Phad, on the inner (closest to the handle) edge of the Big Dipper’s bowl. Then extend this line about eight times downwards, and you’ll arrive at Regulus, the brightest star in that direction. Keep in mind that planets also move nearby, so if you don’t want to mix up Regulus with Venus, read our article on how planets and stars differ.