The Telescopium constellation does not have any stars with confirmed planets or any formally named stars. It is a relatively faint constellation, with no stars brighter than fourth magnitude. The brightest star in the constellation is Alpha Telescopii, with an apparent magnitude of 3.49. It is not home to any Messier objects nor are there any meteor showers associated with the constellation. However, it is home to some notable deep sky objects, including the Telescopium Group.
History and Mythology Of The Telescopium Constellation
Telescopium was created by the French astronomer Nicolas Louis de Lacaille in the 18th century. It was originally given the French name le Telescope and depicted an aerial telescope. In 1763, Lacaille latinized the name to Telescopium.
Johann Bode called the constellation the Astronomische Fernrohr in his 1805 Gestirne and kept its size, but later astronomers Francis Baily and Benjamin Gould subsequently shrank its boundaries. The much-reduced constellation lost several brighter stars to neighbouring constellations: Beta Telescopii became Eta Sagittarii, which it had been before Lacaille placed it in Telescopium, Gamma was placed in Scorpius and renamed G Scorpii by Gould, Theta Telescopii reverted to its old appellation of d Ophiuchi, and Sigma Telescopii was placed in Corona Australis.
Telescopium is not associated with any myths.
Location Of The Telescopium Constellation
Telescopium constellation is the 57th largest constellation and occupies an area of 252 square degrees. It is located in the fourth quadrant of the southern hemisphere (SQ4) and can be seen at latitudes between +40° and -90°.
Its right ascension is 19h and its declination is −50°. It is best seen at 9pm during the month of August. The whole constellation is visible to observers south of latitude 33°N.
Telescopium’s neighboring constellations are Ara, Corona Australis, Indus, Microscopium, Pavo and Sagittarius and it belongs to the Lacaille family of constellations, along with Antlia, Caelum, Circinus, Fornax, Horologium, Mensa, Microscopium, Norma, Octans, Pictor, Reticulum and Sculptor.
Notable Stars
Alpha Telescopii
Alpha Telescopii is the brightest star in the constellation. It is a blue-white subgiant star with the stellar classification of B3 IV and an apparent magnitude of 3.51. It is located around 278 light years away from Earth.
Alpha Telescopii is also classified as a slowly pulsating B star (SPB), which is a type of variable star. It is around 800 times more luminous than the Sun, has five times the mass and three times the radius.
Alpha Telescopii used to belong to Corona Australis, where Ptolemy placed it in the 2nd century, before Lacaille created the constellation.
Zeta Telescopii
Zeta Telescopii is the second brightest star in the constellation and is a yellow giant star belonging to the spectral class G. It has a visual magnitude of 4.10 and is about 127 light years away from Earth.
Epsilon Telescopii
Epsilon Telescopii is the third brightest star in the constellation and has an apparent magnitude of 4.52. It is a binary star system with the stellar classification of K0III, located around 420 light years away from the Sun. The primary component is an orange giant, while the companion is a 13th magnitude star, separated from the primary by 21 arc seconds.
Lambda Telescopii
Lambda Telescopii is the fourth brightest star in the constellation and has an apparent magnitude of 4.85. It is a white main sequence dwarf with the stellar classification of A0V and is around 531 light years away from the Solar System.
Delta Telescopii
Delta Telescopii is a Bayer designation used for two stars, Delta-1 Telescopii and Delta-2 Telescopii. They are separated by 0.16 degrees in the sky.
Delta-1 Telescopii is a blue-white subgiant star of the spectral type B6IV, with an apparent magnitude of 4.92. It is located around 800 light years away from Earth.
Delta-2 Telescopii is a blue-white giant with the stellar classification of B3III and a visual magnitude of 5.07. It is about 1,100 light years away from us.
Eta Telescopii
Eta Telescopii is a white main sequence star with the stellar classification of A0 Vn and an apparent magnitude of 5.03. It is located around 155 light years away from us. It is a member of the Beta Pictoris Moving Group of stars, which all share a common motion through space.
Xi Telescopii
Xi Telescopii is a bright red giant star with the stellar classification of M1IIab and an apparent magnitude of 4.93. It is also classified as an irregular variable star and its luminosity varies from magnitude 4.89 to 4.94. It is located around 1,250 light years away from the Solar System.
Rho Telescopii
Rho Telescopii is a class F dwarf with the stellar classification of F6 V and an apparent magnitude of 5.17. It has a mass that is 2.6 times that of the Sun and is located about 185 light years away from the Solar System.
Iota Telescopii
Iota Telescopii is an orange giant with the stellar classification of K0III and an apparent magnitude of 4.88. It is about 398 light years away from Earth.
Kappa Telescopii
Kappa Telescopii is a yellow giant star with a visual magnitude of 5.18 and is located approximately 293 light years away from Earth. It is thought to be around 1.9 billion years old and has almost 11 times the Sun’s radius and 1.6 times the mass.
Mu Telescopii
Mu Telescopii is a class F main sequence dwarf belonging to the stellar class F5V. It has an apparent magnitude of 6.29 and is located about 120 light years away from the Sun.
Nu Telescopii
Nu Telescopii is a white giant star with the stellar classification of A7II-IV and an apparent magnitude of 5.33. It is located around 170 light years away from the Solar System. It is about 250 million years old.
HIP 92367
HIP 92367 is a yellow giant star with the stellar classification of G8 III and a visual magnitude of 5.802. It can be seen without binoculars in good viewing conditions.
HIP 92367 is located around 360 light years away from the Solar System. It has the same mass as the Sun and three times the Sun’s radius.
Deep Sky Objects
Telescopium Group
The Telescopium Group, also known as AS0851, is a galaxy group consisting of 12 member galaxies and spanning three degrees in the northeastern part of the constellation. The Group is located around 120 million light years away from the Milky Way. Its brightest members are NGC 6868 and NGC 6861.
NGC 6868
NGC 6868 is a giant elliptical galaxy and the brightest object in the Telescopium Group. It was discovered by John Herschel in July 1834 and has an apparent magnitude of 10.6. It contains large, young stars and clouds of dust in its central region, which are not typically found in large elliptical galaxies. This galaxy has also recently collided with another galaxy, most likely a spiral.
NGC 6861
NGC 6861 is a lenticular galaxy with an apparent magnitude of 11. It is the second brightest object in the Telescopium Group and was first discovered by the Scottish astronomer James Dunlop in 1826. The galaxy occupies an area of 3 by 2 arc minutes of apparent sky and is interacting with the brighter NGC 6868. It is thought they will merge into a single galaxy eventually.
NGC 6850
NGC 6850 is a spiral galaxy with an apparent magnitude of 12.6. It was discovered by the English astronomer John Herschel in June 1836.
NGC 6584
NGC 6584 is a globular cluster with an apparent magnitude of 7.9 that is located around 44,000 light years away from Earth.
IC 4699
IC 4699 is a planetary nebula with an apparent magnitude of 13. It can be seen in a 200 mm telescope and is located near Alpha Telescopii and the border with the constellation Corona Australis.
Extra Facts
- The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is “Tel”.
- The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a quadrilateral.
Images:
- Some Images created with the NightVision app – https://www.nvastro.com/nvj.html
- Some Images created with the Stelvision Sky Map https://www.stelvision.com/en/sky-map/
- Telescopium 1 – https://starregistration.net/constellations/telescopium-constellation.html
- Telescopium 3 – https://in-the-sky.org/data/constellation.php?id=81
- NGC 6868 – https://theskylive.com/sky/deepsky/ngc6868-object
- Telescopium 2 – https://en.wikipedia.org/wiki/Telescopium
- NGC 6861 – https://en.wikipedia.org/wiki/NGC_6861
- NGC 6850 – https://www.constellation-guide.com/constellation-list/telescopium-constellation/
- IC 4699 – https://theskylive.com/sky/deepsky/ic4699-object