Antlia is a constellation in the Southern Celestial Hemisphere. Its name means "pump" in Latin and Greek; it represents an air pump. Originally Antlia Pneumatica, the constellation was established by Nicolas-Louis de Lacaille in the 18th century. Its non-specific (single-word) name, already in limited use, was preferred by John Herschel then welcomed by the astronomic community which officially accepted this. North of stars forming some of the sails of the ship Argo Navis, Antlia is completely visible from latitudes south of 49 degrees north.
The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning, the formation of the first galaxies, the way galaxies change over time, and the processes that have generated the variety of structures observed in nearby galaxies. Galaxy formation is hypothesized to occur from structure formation theories, as a result of tiny quantum fluctuations in the aftermath of the Big Bang. The simplest model in general agreement with observed phenomena is the Lambda-CDM model—that is, clustering and merging allows galaxies to accumulate mass, determining both their shape and structure. Hydrodynamics simulation, which simulates both baryons and dark matter, is widely used to study galaxy formation and evolution.
A globular cluster is a spheroidal conglomeration of stars that is bound together by gravity, with a higher concentration of stars towards its center. It can contain anywhere from tens of thousands to many millions of member stars, all orbiting in a stable, compact formation. Globular clusters are similar in form to dwarf spheroidal galaxies, and though globular clusters were long held to be the more luminous of the two, discoveries of outliers had made the distinction between the two less clear by the early 21st century. Their name is derived from Latin globulus. Globular clusters are occasionally known simply as "globulars".
The rotation curve of a disc galaxy is a plot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's centre. It is typically rendered graphically as a plot, and the data observed from each side of a spiral galaxy are generally asymmetric, so that data from each side are averaged to create the curve. A significant discrepancy exists between the experimental curves observed, and a curve derived by applying gravity theory to the matter observed in a galaxy. Theories involving dark matter are the main postulated solutions to account for the variance.
Red supergiants (RSGs) are stars with a supergiant luminosity class and a stellar classification K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous. Betelgeuse and Antares A are the brightest and best known red supergiants (RSGs), indeed the only first magnitude red supergiant stars.
DX Cancri is a variable star in the northern zodiac constellation of Cancer. With an apparent visual magnitude of 14.81, it is much too faint to be seen with the naked eye. Visually viewing this star requires a telescope with a minimum aperture of 16 in (41 cm). Based upon parallax measurements, DX Cancri is located at a distance of 11.8 light-years from Earth. This makes it the 18th closest star to the Sun.
Chi Aquilae is the Bayer designation for a binary star in the equatorial constellation of Aquila, the eagle. This system is bright enough to be seen with the naked eye at a combined visual magnitude of +5.29. Based upon parallax measurements made during the Hipparcos mission, Chi Aquilae is at a distance of approximately 900 light-years from Earth.
In astronomy, the initial mass function (IMF) is an empirical function that describes the initial distribution of masses for a population of stars during star formation. IMF not only describes the formation and evolution of individual stars, it also serves as an important link that describes the formation and evolution of galaxies.
In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space.
Gliese 433 is a dim red dwarf star with multiple exoplanetary companions, located in the equatorial constellation of Hydra. The system is located at a distance of 29.6 light-years from the Sun based on parallax measurements, and it is receding with a radial velocity of +18 km/s. Based on its motion through space, this is an old disk star. It is too faint to be viewed with the naked eye, having an apparent visual magnitude of 9.81 and an absolute magnitude of 10.07.
Eta2 Coronae Australis, Latinized from η2 Coronae Australis, is a solitary star located in the southern constellation of Corona Australis. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.59. Gaia DR3 parallax measurements imply a distance of 770 light years from the Solar System, but it is drifting closer with a radial velocity of −23 km/s. At its current distance Eta2 CrA's brightness is diminished by 0.27 magnitudes due to stellar extinction from interstellar dust and it has an absolute magnitude of −0.24.
θ Pavonis, Latinized as Theta Pavonis, is a single star in the southern constellation of Pavo. It is just visible to the naked eye as a dim, white-hued star, having an apparent visual magnitude of 5.71. This star is located 213 light years from the Sun based on parallax.
HD 126053 is the Henry Draper Catalogue designation for a star in the equatorial constellation of Virgo. It has an apparent magnitude of 6.25, which means it is faintly visible to the naked eye. According to the Bortle scale, it requires dark suburban or rural skies to view. Parallax measurements made by the Hipparcos spacecraft provide an estimated distance of 57 light years to this star. It is drifting closer with a heliocentric radial velocity of −19.2 km/s.
NGC 720 is an elliptical galaxy located in the constellation Cetus. It is located at a distance of circa 80 million light years from Earth, which, given its apparent dimensions, means that NGC 720 is about 110,000 light years across. It was discovered by William Herschel on October 3, 1785. The galaxy is included in the Herschel 400 Catalogue. It lies about three and a half degrees south and slightly east from zeta Ceti.
PHL 293B, also known as Kinman's dwarf, is a low-metallicity blue compact dwarf galaxy about 22.6 Mpc from the Earth in the constellation Aquarius.
BG Indi, also known as κ1 Indi is a multiple star system in the southern constellation of Indus. Its average apparent magnitude is 6.141, meaning it can only be seen by the naked eye under exceptionally good viewing conditions. Stellar parallax measurements by Gaia put the system at about 166 light-years away.
HD 75171, also known as HR 3495, is a solitary, white hued star located in the southern constellation of Volans. It has an apparent magnitude of 6.02, making it faintly visible to the naked eye under ideal conditions. The object is relatively close at a distance of 191 light years but is receding with a heliocentric radial velocity of 10.7 km/s. Eggen (1995) lists it as a probable member of the Hyades Supercluster.
