Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site noao.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!sdcsvax!sdcrdcf!hplabs!hao!noao!sharp From: sharp@noao.UUCP (Nigel Sharp) Newsgroups: net.astro Subject: re:planet discovered around another star Message-ID: <451@aquila.noao.UUCP> Date: Fri, 21-Dec-84 10:19:17 EST Article-I.D.: aquila.451 Posted: Fri Dec 21 10:19:17 1984 Date-Received: Sat, 5-Jan-85 04:07:47 EST References: <1352GMS@PSUVM> Organization: Natl. Optical Astronomy Observatories, Tucson, AZ USA Lines: 43 > I believe that there is some controversy surrounding the apparant > discovery of a 'planet' orbiting another star in Ophiuchus. The controversy > is not concerning the object itself, for it is most certainly there, but > rather what to call it. > > To be rather picky about names, this object should be termed a 'brown > dwarf' rather than a planet. Current theories of solar system formation > include the probable existance of such objects. ... ... Hear hear ! I hesitated to say anything about this, for reasons below. > With an upper-atmosphere temperature of about 2000 degrees (Farenheit, > Celsius or Kelvin???) this object is certainly undergoing fusion at its > center. ... ... Not certainly. A very interesting debate is in progress about the exact behaviour of low-mass stars, and precisely when nuclear burning sets in. I favour the existence of nuclear burning in such an object, making it clearly not a planet. It is worth noting that there ARE definitions of planets (by quite reputable people) which would exclude the Earth (no internal power generation is one criterion which would exclude us, unless you insist on some sort of "significant" qualifier). However, the VB8B results is very interesting: it's just not what most people would term a planet (recent comment "if I flew a layman past it, he'd call it a star"). > At any rate, I am mentioning this nitpicky argument primarily in response > to some people who have said that the nitpicky argument is really being > generated by astronomers who are jealous at not having found the first > planet themselves. ... ... Precisely why I have been silent. > Although I applaud the achievements of the astronomers who discovered > the first 'brown dwarf', lets recognize it for what it is. The brown dwarf > is no more a planet than were the rings of dust discovered by IRAS > around Vega and Fomulhaut. > Gerry Santoro > Microcomputer Information and Support Center GMS @ PSUVM (bitnet) |||||| No axe to grind ! -- Nigel Sharp [noao!sharp National Optical Astronomy Observatories]