h2g2 - Constellations: Fornax 'the Furnace'

Name:	Fornax (Latin: 'Furnace')
Genitive:	Fornacis
Short form:	For
Originally:	Fornax Chemica ('chemical furnace')
Area:	398 sq deg
Co-ordinates¹:	Right Ascension 03^h, 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.

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



	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 three extrasolar planetary systems found in the constellation Fornax up to 2010. HIP 13044 b is interesting because it is the first extrasolar planet which originated from another galaxy, now absorbed into the Milky Way.

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 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
HD 16417	HD 16417 b	0.07	17.2	2009	'Hot Neptune'
HIP 13044	HIP 13044 b	1.25	16.2	2010	'Hot Jupiter'



	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.