Constellations: Fornax 'the Furnace'
Created | Updated Nov 18, 2017
Camelopardalis | Cancer | Canes Venatici | Canis Major | Canis Minor | Capricornus | Carina | Cassiopeia | Centaurus
Cepheus | Cetus | Chamæleon | Circinus | Columba | Coma Berenices | Corona Australis | Corona Borealis | Corvus
Crater | Crux | Cygnus | Delphinus | Dorado | Draco | Equuleus | Eridanus | Fornax | Gemini | Grus | Hercules | Horologium
Hydra | Hydrus | Indus | Lacerta | Leo | Leo Minor | Lepus | Libra | Lupus | Lynx | Lyra | Mensa | Microscopium | Monoceros
Musca | Norma | Octans | Ophiuchus | Orion | Pavo | Pegasus | Perseus | Phoenix | Pictor | Pisces | Piscis Austrinus
Puppis | Pyxis | Reticulum | Sagitta | Sagittarius | Scorpius | Sculptor | Scutum | Serpens | Sextans | Taurus
Telescopium | Triangulum | Triangulum Australe | Tucana | Ursa Major | Ursa Minor | Vela | Virgo | Volans | Vulpecula
Name: | Fornax (Latin: 'Furnace') |
Genitive: | Fornacis |
Short form: | For |
Originally: | Fornax Chemica ('chemical furnace') |
Area: | 398 sq deg |
Co-ordinates1: | Right Ascension 03h, Declination −30° |
Origin: | Modern |
Fornax, 41st in size of the 88 internationally recognised constellations, is nestled into a bend of the constellation Eridanus, the river. It also shares borders with Cetus, Sculptor and Phoenix. Fornax is a modern constellation, created after 1754 by French astronomer Nicolas Louis de Lacaille (1713 - 62). In the mid-18th Century, Lacaille studied the stars of the southern hemisphere from the Cape of Good Hope, mapping over 10,000 stars and 42 nebulous objects, and formed 14 new constellations.
Fornax was originally named Fornax Chemica (Chemical Furnace). The last part has dropped out of use. It was named in honour of the French chemist Antoine Laurent Lavoisier who established that burning is a process that involves the combination of a substance with oxygen. He also demonstrated that water is formed from oxygen and hydrogen.
There are no Messier objects, no meteor showers and no bright stars in Fornax. But that doesn't mean there's nothing to interest the reader. This constellation has a planetary nebula, NGC 1360. Fornax also boasts a number of spectacular galaxies, including a really rich cluster of 58 galaxies called the Fornax Cluster.
Stars
The scientific star names are simple to understand (if you know your Greek alphabet). For example: 'alpha Fornacis' means it's the brightest star in the constellation Fornax. The next brightest is designated 'beta', and so on. Combined with the genitive name, this is known as the 'Bayer designation'. Alpha Fornacis is a binary star system that's just 46 light years2 away. UDF 2457 is a red dwarf some 59,000 light years distant. Identified on the Hubble Ultra Deep Field (UDF), it is one of the furthest-known stars which reside in the Milky Way.
Star Table
Star | Designation | Magnitude | Distance
(light years) | Spectral classification and/or comments |
α For | alpha Fornacis | +3.8 var | 46 | Binary star system |
β For | beta Fornacis | +4.45 | 170 | Double star system |
γ For | gamma Fornacis | +4.68 var | 360 | Blue-white main sequence |
δ For | delta Fornacis | +5.0 | 700 | Blue-white giant |
λ2 For | lambda2 Fornacis | +5.78 var | 81 | Yellow dwarf/has a planet |
UZ For(AB) | UZ Fornacis(AB) | +18 var | - | Eclipsing binary cataclysmic variable with planetary system |
UDF 2457 | UDF 2457 | +25 | 59,000 | Red dwarf |
New General Catalogue (NGC)
The NGC was compiled by John Louis Emil Dreyer (the director of the Armagh Observatory from 1882 - 1916).
NGC 1097 is a Seyfert galaxy. This type of galaxy, identified in 1943 and named after their discoverer Carl Keenan Seyfert, have an intensely bright, compact and highly active nucleus, caused by a supermassive black hole at their core. NGC 1097 has a companion galaxy 42,000 light years from its centre, and one of the larger galaxy's spiral arms seems to be embracing it. The galaxies will eventually merge, over millions of years.
NGC Galaxy Table
Catalogue number | Galaxy type | Brightness (m) | Distance
(light years) |
NGC 1097 (Arp 77) | Barred Seyfert CW spiral | +10.2 | 45m |
NGC 1316
(Fornax A) | Post-merger elliptical | +9.4 | 59m |
NGC 1350 | CW spiral | +11.2 | 85m |
NGC 1365 | Barred CW spiral | +10.3 | 60m |
NGC 1380 | Lenticular | +10.9 | 61m |
NGC 1381 | Lenticular | +12.3 | 61m |
NGC 1398 | ACW barred spiral | +10.6 | 55m |
NGC 1399 | Elliptical | +10.5 | 60m |
NGC 1404 | Elliptical | +10.9 | 60m |
NGC 1427 | Elliptical | +11.8 | 70m |
NGC 1427A | Barred irregular | +13.4 | 62m |
Other Galaxies
Fornax Dwarf
Fornax Dwarf is a spheroidal galaxy which orbits the Milky Way. There are several globular clusters (tightly packed balls of stars) orbiting it.
Luminous Blue Compact Galaxy
J033728.8-352708 is a Luminous Blue Compact type galaxy (LBCG) that’s so distant it registers a redshift of 0.08. If an object is travelling away from us quickly enough, the light waves from it are stretched out, making visible light appear redder than it actually is, hence 'redshift'. The expansion of the Universe means that more distant objects are travelling away from us quicker. A redshift of 0.08 gives us a rough distance of a billion light years. We are seeing the light from its cosmic history - that is, the object was there a billion years ago, it may no longer be there, but we have no way of knowing. Now that's a galaxy that's far, far away!
Extrasolar Planets in Fornax
There has been several extrasolar planetary systems found in the constellation Fornax. HIP 13044 b is interesting because it is the first detected extrasolar planet which originated from another galaxy, now absorbed into the Milky Way.
HD 20781 and HD 20782 are a binary pair separated by over 9,000 AU (astronomical units - 1 AU is equivalent to Earth/Sun distance). Both stars host planetary systems. HD 20782 is similar in temperature and mass to our own Sun. Its solo planet is a gas giant in a highly eccentric orbit. The companion HD 20781 has two Neptune-mass planets which orbit so close to their parent star (both within Mercury's orbit in our Solar System) that they are classified 'hot'.
UZ Fornacis(AB) is a cataclysmic variable binary system made up of a white dwarf and a red dwarf which orbit each other in just over two hours. The white dwarf is constantly stripping the donor red dwarf of stellar material, which may end up causing a supernova. This complex and volatile system is host to two circumbinary superjovian worlds.
Figures given in the table below are the length of the planet's orbital period around its parent star, which we know of as a year. The mass of the extrasolar planet is compared with that of Jupiter, our solar system's largest planet. This is known by astronomers as the 'Jovian scale'.
Extrasolar Planets Table
Star name or
catalogue number | Planet
catalogue number | Planet mass
(Jovian scale) | Orbital period
(Earth days) | Year of discovery | Comments |
HD 20781 | HD 20781 b | 0.04 | 29 | 2011 | 'Hot Neptune' |
HD 20781 | HD 20781 c | 0.05 | 85 | 2011 | 'Hot Neptune' |
HD 20782 | HD 20782 b | 2.03 | 586 | 2006 | Gas giant; high eccentric orbit |
HD 20868 | HD 20868 b | 1.99 | 380.85 | 2008 | Superjovian; habitable zone |
lambda2 | lambda2 b | 0.07 | 17.2 | 2009 | 'Hot Neptune' |
WASP-72 | WASP-72 b | 1.55 | 2.22 | 2013 | Hot gas giant |
UZ For(AB) | UZ For(AB) c | 6.3 | 5,800 | 2010 | Superjovian |
UZ For(AB) | UZ For(AB) d | 7.7 | 1,900 | 2011 | Superjovian |
Hubble Ultra Deep Field
The famous Hubble Ultra Deep Field is the deepest view of the universe ever seen. It contains images of galaxies which formed 13 billion years ago, roughly 95% of the current age of the universe. It took over ten weeks of gazing at the same area in Fornax to capture the complete vista of galaxies. The Hubble Ultra Deep Field will be studied by many researchers eager to learn about the early universe.