Yes, I think that is mostly correct, although the mechanism doesn't necessarily have to be explosive. Also, what is "seen" should be better defined. Actual astrospheres (except for planetary nebulae and perhaps some other relatively rare types of stars, such as Vega, which has an apparent dusty disk) are not observed so much in visual light as they are in other areas of the electromagnetic spectrum, due to the much higher energies from mostly electron and proton particles emitted by the star. I don't pretend to know astrophysics as well as others, so someone else may correct me, but I think I'm right. Kim -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of M Wilson Sent: Monday, December 27, 2010 1:02 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] So Long, Solar System Inotherwords, it has to have some sort of expolsion where a lot more gas is ejected into space for it show up. Is that what you're saying? --- On Mon, 12/27/10, Kim <kimharch@cut.net> wrote: From: Kim <kimharch@cut.net> Subject: Re: [Utah-astronomy] So Long, Solar System To: "'Utah Astronomy'" <utah-astronomy@mailman.xmission.com> Date: Monday, December 27, 2010, 11:28 AM Oops, let me rephrase that last statement a bit: I think the heliosphere (i.e. OUR sun's astrosphere) might be too tenuous to show anything, but the astrospheres or stellar wind bubbles of other stars are observable from earth. Planetary nebulae, I believe, are a special case of an old star's astrosphere that allows it to be seen in visible light. Kim -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of M Wilson Sent: Monday, December 27, 2010 11:15 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] So Long, Solar System Okay Joe (or anybody), I have a question. If someone on a distant planet took an astro-photo type picture of our little star, would the heliosphere show up as something similar to the Bubble Nebula? Or is the gas and partricles just to tenuous for it to be detected. --- On Sun, 12/26/10, Joe Bauman <josephmbauman@yahoo.com> wrote: From: Joe Bauman <josephmbauman@yahoo.com> Subject: [Utah-astronomy] So Long, Solar System To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, December 26, 2010, 1:21 AM Voyager 1 has reached a region where the solar wind is no longer flowing outward, nearly to interstellar space. If anyone would care to read and comment on my blog I'd be grateful: http://www.deseretnews.com/blog/47/10011134/Nightly-news-astronomy-Onward-to -Interstellar-Space.html Thanks, Joe _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1191 / Virus Database: 1435/3342 - Release Date: 12/27/10 _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1191 / Virus Database: 1435/3342 - Release Date: 12/27/10