Telescopium is a minor constellation in the southern celestial hemisphere, one of twelve named in the 18th century by French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments.

Eta and PZ Telescopii are two young star systems with debris disks and brown dwarf companions.

[5] Johann Bode called it the Astronomische Fernrohr in his 1805 Gestirne and kept its size, but later astronomers Francis Baily and Benjamin Gould subsequently shrank its boundaries.

[7] The original object Lacaille had named Eta Telescopii—the open cluster Messier 7—was in what is now Scorpius, and Gould used the Bayer designation for a magnitude 5 star, which he felt warranted a letter.

[7] A small constellation, Telescopium is bordered by Sagittarius and Corona Australis to the north, Ara to the west, Pavo to the south, and Indus to the east, cornering on Microscopium to the northeast.

[8] The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a quadrilateral.

[17] The faint (magnitude 12.23) Gliese 754, a red dwarf of spectral type M4.5V, is one of the nearest 100 stars to Earth at 19.3 light-years distant.

[26] Another irregular variable, RX Telescopii is a red supergiant that varies between magnitudes 6.45 and 7.47,[33] just visible to the unaided eye under good viewing conditions.

[35] Dipping from its baseline magnitude of 9.6 to 16.5,[36] RS Telescopii is a rare R Coronae Borealis variable—an extremely hydrogen-deficient supergiant thought to have arisen as the result of the merger of two white dwarfs; fewer than 100 have been discovered as of 2012.

[40] QS Telescopii is a binary system composed of a white dwarf and main sequence donor star, in this case the two are close enough to be tidally locked, facing one another.

Known as polars, material from the donor star does not form an accretion disk around the white dwarf, but rather streams directly onto it.

[43] The system is complex, as it has a common proper motion with (and is gravitationally bound to) the star HD 181327, which has its own debris disk.

[46] PZ Telescopii is another young star with a debris disk and substellar brown dwarf companion, though at 24 million years of age appears too old to be part of the Beta Pictoris moving group.

Using the High Accuracy Radial Velocity Planet Searcher (HARPS) instrument on the ESO 3.6 m Telescope, it was found to have a brown dwarf around 38 times as massive as Jupiter orbiting at an average distance of 1.35 AU with a period of 505 days.

[51] Occupying an area of around 4' × 2', NGC 6845 is an interacting system of four galaxies—two spiral and two lenticular galaxies—that is estimated to be around 88 megaparsecs (287 million light-years) distant.

[53] SN 1998bw was a luminous supernova observed in the spiral arm of the galaxy ESO184-G82 in April 1998, and is notable in that it is highly likely to be the source of the gamma-ray burst GRB 980425.