Many planets are known to the civilized peoples of the Haliburn Galaxy; these are the main ones.
Iriond is the birthplace of humanity, and is the most highly-developed world. Although there are indications of advanced societies in Rancent's world that are much older, Iriond boasts the oldest civilized race (i.e. humans) with a continuously-recorded history.
Asherah (5114 Mezravi IV)
Asherah is one of the first few planets to be explored by humans (after Iriond, of course), having been colonized by the Confederacy. Home to a few humanoid races such as Eblians and Shaugmar.
Chertan V: A stormy planet colonized by people affiliated with the Allied Free Nations (mostly from Inyad and Hellonde).
6072 Reshep II
6072 Reshep II is home to a powerful psychic race, the Reshepans. It was colonized by the Confederacy, which has brought Reshepans into their fold, although relations are uneasy.
4658 Austolus III (New Eugeron)
4658 Austolus III (a.k.a. New Eugeron): Colonized by Muranian humans, this planet became an extension of the Pan-Muranian Union. It is tidally locked; the upper portion of the map points toward the sun, and the lower half is plunged in an eternal night.
2514 Bhadrapada VI (Rancent's World, New Earth)
2514 Bhadrapada VI (a.k.a. Rancent's World, New Earth) is a planet only recently settled by humans (about 800 years), but which is home to a variety of civilized and not-so-civilized species, and archaeology points to a rich civilized past hundreds of milennia old.
9911 Maenali IV
9911 Maenali IV is a scarcely settled world (by humans, at least; it has a considerable variety of native life), much of which is rather inhospitable.