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How visible is Sirius B from Sirius A?
On 03/05/14 00:15, Mike Dworetsky wrote:
Brad Guth wrote: Sirius(b) is mostly emitting photons in the UV spectrum, so don't expect any human visual capability of even telescope aided views of that one. Which of course does not explain why Sirius B was discovered visually in the 1860s during testing of a new Alvan Clark refractor, and I myself saw it through the Mt Wilson 60-in telescope in the 1970s. It's faint, but the main viewing difficulty is its proximity to bright Sirius, not its low luminosity. I also saw Sirius B through through the 60-inch, but I did it about a year ago -- and through thin clouds to boot. Piece of cake. You could drive a metaphorical truck between A and B. -- Bill Owen |
#12
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How visible is Sirius B from Sirius A?
Many thanks indeed for the responses to my question - it's all been very helpful!
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#13
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How visible is Sirius B from Sirius A?
On Wednesday, March 5, 2014 12:15:54 AM UTC-8, Mike Dworetsky wrote:
Brad Guth wrote: Sirius(b) is mostly emitting photons in the UV spectrum, so don't expect any human visual capability of even telescope aided views of that one. Which of course does not explain why Sirius B was discovered visually in the 1860s during testing of a new Alvan Clark refractor, and I myself saw it through the Mt Wilson 60-in telescope in the 1970s. It's faint, but the main viewing difficulty is its proximity to bright Sirius, not its low luminosity. -- Mike Dworetsky (Remove pants sp*mbl*ck to reply) I stand corrected, as only a good 90% of its illumination energy is in the UV. The 10% in the visual spectrum should be visible, though barely. What's the photosphere/atmosphere of Sirius(b) made of? So, where's all of those terrific photosphere images of Sirius A? |
#14
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How visible is Sirius B from Sirius A?
In article ,
John writes: ... a massive effort to probe Europa with absolutely guaranteed sterile robots should be made as soon as practicable. Or sooner. [And "absolutely sterile" *must* be guaranteed before we even consider how to do it. Terran life is hardy stuff.] "Absolutely sterile" is impossible. When the time comes to design a Europa lander or penetrator, I'd expect debate over how nearly sterile is good enough. There's an IAU group cognizant of such issues, but it won't surprise me if the debate is escalated to political authorities. -- Help keep our newsgroup healthy; please don't feed the trolls. Steve Willner Phone 617-495-7123 Cambridge, MA 02138 USA |
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