Re: [Utah-astronomy] Utah-Astronomy Digest, Vol 118, Issue 1 re: super massive black hole
It's important to realize that black holes don't just "suck" everything around them in. If the Sun were to suddenly be replaced by a black hole, the Earth would simply continue to orbit as it does now (granted, things wouldn't be very nice here). It's only when there's enough friction to slow things down that they spiral in. Or, tidal processes can be strong enough on a closely approaching satellite star to pull matter of, just as happens in a binary system where one is a white dwarf, neutron star, or black hole. There are some stars that come incredibly close the the 3-4 MILLION solar mass (!) black hole at the center of the Milky Way. These stars have been monitored using space-based microwave observatories and ground-based radio observatories for over 15 years (only longer wavelengths can penetrate through the dust and gas between us and Sag A* (That should have shown up as an asterisk after the capital A, and is read: "Sagittarius A-star" -- did the quotation marks show up?? you never know what's going to be translated in email text), and in the last few years adaptive optics on the World's great ground based 'scopes have added to the data. A good summary of this long project, including some great time laps animations can be found here: http://www.eso.org/public/news/eso0846/ The reason it's pretty clear that our supermassive black hole is not gobbling lots of stuff up the way it no doubt did earlier in the life of the galaxy is that we don't see much evidence of it the way we do in what are called "active galaxies" that often have these incredible jets of matter and radiation streaming out of them. A great example is M-87, the great Virgo galaxy. Once again, it wasn't until the advent of more advanced space-based as well as ground-based telescopes that the evidence began to pile up. John R. Peterson -----Original Message-----
Message: 1 Date: Sat, 1 Dec 2012 00:06:17 -0700 From: RON VANDERHULE <deepsky100@msn.com> To: utah-astronomy <utah-astronomy@mailman.xmission.com> Subject: [Utah-astronomy] super massive black hole Message-ID: <BAY164-W24069E1C041CE7E12F4BE281420@phx.gbl> Content-Type: text/plain; charset="iso-8859-1"
I am not sure what I am missing about the unusual nature of NGC 1277 and its' massive black hole. Isn't the purpose of a black hole to feed on its' host galaxy until the meal is finished? So the more a black hole consumes the bigger it gets and the smaller the host galaxy gets. We see this in NGC 1277 and it will be our fate also in the future. Yes? As long as I have your attention what percentage of time does the Universe spend reshuffling and merging of galaxies as compared to existing in a somewhat finished state???
Ron
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John R. Peterson