wdr@faron.UUCP (William D. Ricker) (03/12/85)
In article <1075@utastro.UUCP> dipper@utastro.UUCP (Debbie Byrd and Harlan Smith), StarDate March 9 Planets for Distant Stars, is >It was announced that VB-8 has a "planet" -- an object not >massive enough to have its own internal nuclear fusion reactions -- the >internal power source that enables stars like our sun to shine. . : >Planets are fundamentally "cold" objects. Their >brightness comes from reflected starlight. VB-8B shines by virtue of >its glowing hot surface. It's an interesting object -- only about half >as massive as the next-smallest star so far known -- but still dozens >of times more massive than the largest planet known, Jupiter. >Nature probably doesn't distinguish sharply between stars and planets, >though WE have separate words for them. Question: I thought Jupiter radiated more energy than it absorbed from Sol? I.e., Jupiter isn't "fundamentally 'cold'" but rather star-like. If this VB-8 companion is a Brown Dwarf not a planet, how is Jupiter a Planet? (Beyond the historical significance of being an visible night-sky wanderer.) It seems to me that we know of no system which is certainly without a stellar companion, present location included. But then, I'm not a professional astro-whatever, and not really a serious amateur anything but diletante. Would the Pro-Astro folks please respond with their guidelines for classifying astronomic objects (taxonomy), preferably using well-known examples as illustrations? e.g., VB-8-companion, Jupiter, Sirius Companion, and other much discussed arguable cases. I would appreciate with each "judgement call" on the marginal cases a statement of what experimental (plausibly observable) evidence would be required to change the categorization. -- William Ricker wdr@MITRE-Bedford.ARPA (MIL) wdr@faron.UUCP (UUCP) decvax!genrad!linus!faron!wdr (UUCP) {allegra,ihnp4,utzoo,philabs,uw-beaver}!linus!faron!wdr (UUCP) Opinions are my own and not necessarily anyone elses. Likewise the "facts".