Match the Star Trivia Quiz

Answer: Aldebaran

Aldebaran is a red giant star, the brightest in the constellation of Taurus and the fourteenth brightest in the night sky. Aldebaran is regarded as one of the easiest stars to locate, as it is located in the opposite direction to Sirius, the brightest star in the night sky, from Orion's Belt.

The star is classed as K5+III on the stellar classification spectrum, with a radius approximately 44 times that of the Sun. In 1993, evidence was found indicating the possible existence of an exoplanet orbiting Aldebaran.

This planet, which was confirmed in 2015, is estimated to be around five times the size of Jupiter, with an orbit of around 45% greater than that of Earth around the Sun.

Answer: Alpha Centauri

The two stars of the Alpha Centauri system are among the closest to the Sun, being located less than 4.5 light years away. The system's primary, Rigel Kentaurus (also known as Alpha Centauri A), is a yellow main sequence star classed as G2V on the stellar classification scale.

As such, it has similar properties to the Sun, which is also a G2V yellow star. Rigel Kentaurus is approximately 10% more massive, with a 22% larger radius than the Sun. The second member of the system, Toliman (aka Alpha Centauri B), is a smaller orange main sequence star classed as K1V.

It has 90% of the Sun's mass and is 14% smaller in diameter. The pair orbit a common centre of mass at a variable distance of between 11.2 and 35.6 AUs, with one orbit taking approximately 80 years.

A third member of the system, named Proxima Centauri, orbits the centre of mass at a distance of approximately 13,000 AUs.

Answer: Barnard's Star

Barnard's Star is a small red dwarf star that is one of the closest to the Sun, being located just under 6 light years away. As a red dwarf, it is too dim to be able to see with the naked eye, with its small size leading to it only being properly noticed just over a century ago, when astronomer EE Barnard calculated its proper motion based on photographs taken in 1888, 1890 and 1916; to commemorate this work, the star was named for Barnard. Barnard's Star is classed as M4 on the stellar classification scale, and is estimated to be anywhere between 7 and 12 billion years old, making it one of the oldest stars yet studied within the Milky Way.

In 2018, it was announced that an exoplanet had been detected orbiting Barnard's Star.

Answer: Betelgeuse

Betelgeuse is a red supergiant, and is one of the largest visible stars in the night sky. The tenth most-visible star from Earth, Betelgeuse forms the right shoulder of Orion, and is easily distinguishable by its bright red colour. Classified as M1-2Ia-ab on the stellar classification scale, Betelgeuse is identified as a so-called 'runaway star', meaning that it is moving through the interstellar medium at a high velocity having been ejected from the area of its creation.

The star's mass, estimated to be between ten and twenty times that of the Sun, allows its age to be estimated as around 10 million years, and indicates that Betelgeuse will end its life cycle as a supernova at some point within 100,000 years. Betelgeuse forms one of the points of the so called 'Winter Triangle', a grouping of three stars visible during the northern winter, alongside Sirius and Procyon.

Answer: Canopus

Canopus is the second brightest star in the night sky. A so-called 'bright giant' classed as A9 on the stellar classification scale, it is eight times as massive as, and has 71 times the radius of, the Sun. Further, its luminosity is 10,000 times that of the Sun; no closer star is more luminous than Canopus, which has meant that three times during the past four million years, Canopus has been the brightest star in the night sky, and has only been eclipsed from this position when other stars pass closer to the Solar System.

Answer: Deneb

Deneb is a blue-white supergiant star that is amongst the most luminous in the night sky. The nineteenth brightest visiblestar from Earth, Deneb is located in the constellation Cygnus at a distance estimated to be more than 2600 light years. Classed as A2Ia on the stellar classification spectrum, Deneb's diameter is more than 200 times that of the Sun. Deneb is believed to be going through a phase of expansion and contraction, combined with heating and cooling, having evolved past the main sequence. Depending on its mass, the star will either evolve into a red supergiant, or will heat up before cooling once again and expand into an even more massive type, such as a yellow hypergiant or Wolf-Rayet star.

In either eventuality, Deneb is expected to ultimately explode in a supernova.

Answer: Pollux

Pollux is the closest giant star to the Sun, at a distance of just 34 light years. The eighteenth brightest star in the night sky, Pollux was originally an A-type main sequence star. It has since has evolved past the main sequence to become an orange giant classified as K0III.

It is approximately twice the mass and nine times the diameter of the Sun, and is the brightest star in Gemini. In 2006, an exoplanet was confirmed as being in orbit of Pollux. This planet, which was given the name Thestias, is estimated to be just over twice the mass of Jupiter, and orbits Pollux at a distance of approximately 1.5 AUs.

Answer: Proxima Centauri

Proxima Centauri is a red dwarf star that is just 4.2 light years from the Sun, making it the closest star to the Solar System. Technically part of the Alpha Centauri system, it orbits Rigel Kentaurus and Toliman at a distance of roughly 13000 AUs (0.21 light years), taking 550,000 years to complete one orbit. Unlike the two main stars in Alpha Centauri, Proxima is too faint to be seen with the naked eye. Classified as M5.5 on the stellar classification scale, Proxima was first discovered in 1915 by Robert Innes, who noted it had the same proper motion as Alpha Centauri, and suggested its name. Proxima has two confirmed exoplanets in orbit around it, with one, Proxima Centauri b, believed to exist within the star's estimated habitable zone.

Answer: Sirius

Sirius is well-known as the brightest star in the night sky. The system is a binary; Sirius A is a white main sequence star classed as A0mA1Va, approximately twice as massive as the Sun, while Sirius B is a white dwarf classed as DA2. Sirius B was a main sequence star similar to its companion, although with much greater mass, which led it to expend its hydrogen core more quickly than Sirius A.

This led to it swelling into a red giant some 120 million years ago, before shrinking into its current form, which, although it retains a mass of around 1.2 solar masses, is in a body approximately the volume of Earth. Sirius A will go through a similar evolution as it uses up its hydrogen core. Sirius A forms one of the points of the so called 'Winter Triangle', a grouping of three stars visible during the northern winter, alongside Betelgeuse and Procyon.

Answer: Wolf 359

Wolf 359 is a red dwarf star, one of the faintest and lowest mass stars known. Located less than eight light years away, it is also one of the closest stars to the Sun, with only the three elements of the Alpha Centauri system and Barnard's Star being closer. Classed as M6.5 on the stellar classification scale, Wolf 359 cannot be seen with the naked eye.

It was discovered when its proper motion was measured by the astronomer Max Wolf in 1917. Two years later, he published a catalogue of over one thousand stars whose motions he had measured, with this numbered as number 359 on the list, which is how it received its name. Wolf 359 has less than 10% of the Sun's mass, and is only just above the threshold in which a star can initiate nuclear fusion.

Its slow rate of consumption of its hydrogen core means that Wolf 359 will be able to sustain itself as a main sequence star for an estimated eight trillion years. In 2019, evidence was found that there may be at least two exoplanets orbiting Wolf 359.