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RE: [Utah-astronomy] Out of the Blue
by Kim Hyatt 18 Dec '03

18 Dec '03

Chuck - Thanks for that cheerful note to start my day! ;) -----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Thursday, December 18, 2003 7:45 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Out of the Blue Burnham was a talented, self-taught astronomer who was lucky enough to land his job in the days before a formal education was a requirement. As time progressed, though, he was eventually displaced by an attitude that only recognized certifications rather than ability. He finally lost his observing job, and a marketing change by his publisher pretty much dried-up his royalties (it went to the BOM club), leaving him destitute. He died insane, in abject poverty, doing paintings on the boardwalk for pennies. C. --- Jim Gibson <xajax99(a)yahoo.com> wrote: > Burnham's has a copyright of 1958-1979 and the NGC > 2000.0 has a copyright of 1988. Without deeper > research, in other words, taking a guess and > applying your descriptions of how magnitudes are > derived, I would guess that Burnham took his > magnitudes out of the blue (pun intended) and > Sinnott's may align more closely with the visual. __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/ _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com

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Fwd: [Utah-astronomy] In the blue (Modified by James Cobb)
by James Cobb 17 Dec '03

17 Dec '03

My apologies if this comes through twice. My mailer sometimes sends from the wrong account and the message is bounced by the utah-astronomy mailing list. Jim ---- Jim Cobb james(a)cobb.name Begin forwarded message: > Resent-From: James Cobb <james(a)cobb.name> > From: utah-astronomy-owner(a)mailman.xmission.com > Date: December 17, 2003 6:39:11 PM MST > Resent-To: Utah Astronomy <utah-astronomy(a)mailman.xmission.com> > To: jamescobb(a)mac.com > Subject: Re: [Utah-astronomy] In the blue (Modified by James Cobb) > > The following is from "Realm of the Universe," by George Abell, (c) > 1976, p. 219, my old college text... > >> Magnitudes, whether apparent or absolute, that are based on stellar >> brightness as they are observed with the human eye are called visual >> magnitudes or absolute visual magnitudes. Today photographic plates >> or photomultipliers can be used in conjunction with many kinds of >> color filters to produce a great variety of different magnitude >> systems–for example, red magnitudes, ultraviolet magnitudes, infrared >> magnitudes, and so on. A certain few spectral bands have become more >> or less standard, however, and are now widely used to define >> magnitudes. >> >> Since about 1960 the most commonly used magnitudes have been U >> (ultraviolet), B (blue), and V (visual). The U and B magnitudes are >> obtained from measures of the flux from stars through certain >> standardized ultraviolet and blue filters with a common type of >> photomultiplier. The visual magnitude (V) is measured with the same >> photocell through a filter that approximates the response of he human >> eye. The difference between any two of these magnitudes, say between >> blue and visual magnitudes (B-V), is called a color index. Since the >> inverse square law of light applies equally to all wavelengths, the >> color index of a star would not change if the star's distance were >> changed. > > So, Chuck wins the memory prize on the subject. > > ---- > Jim Cobb > james(a)cobb.name > > >

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Re: [Utah-astronomy] In the blue (Modified by James Cobb)
by utah-astronomy-owner＠mailman.xmission.com 17 Dec '03

17 Dec '03

The following is from "Realm of the Universe," by George Abell, (c) 1976, p. 219, my old college text... > Magnitudes, whether apparent or absolute, that are based on stellar > brightness as they are observed with the human eye are called visual > magnitudes or absolute visual magnitudes. Today photographic plates > or photomultipliers can be used in conjunction with many kinds of > color filters to produce a great variety of different magnitude > systems–for example, red magnitudes, ultraviolet magnitudes, infrared > magnitudes, and so on. A certain few spectral bands have become more > or less standard, however, and are now widely used to define > magnitudes. > > Since about 1960 the most commonly used magnitudes have been U > (ultraviolet), B (blue), and V (visual). The U and B magnitudes are > obtained from measures of the flux from stars through certain > standardized ultraviolet and blue filters with a common type of > photomultiplier. The visual magnitude (V) is measured with the same > photocell through a filter that approximates the response of he human > eye. The difference between any two of these magnitudes, say between > blue and visual magnitudes (B-V), is called a color index. Since the > inverse square law of light applies equally to all wavelengths, the > color index of a star would not change if the star's distance were > changed. So, Chuck wins the memory prize on the subject. ---- Jim Cobb james(a)cobb.name

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RE: [Utah-astronomy] In the blue
by Kim Hyatt 17 Dec '03

17 Dec '03

Thanks Chuck. -----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Wednesday, December 17, 2003 6:10 PM To: Utah Astronomy Subject: RE: [Utah-astronomy] In the blue Ok, here it is from memory. Early plates were taken twice, once with a blue-sensitive emulsion, once with a yellow (or red, not sure after all these years) emulsion. Subtracting one value from the other yields a "color index" for the star, helping place it on the H-R diagram. When the visual values were written-down, typically only one exposure was consulted, the blue one. Some objects are MUCH brighter to the eye than they appear on a blue-sensitive plate. I may not have recalled it 100% accurately, but I think that's the gist of it. C. __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/ _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com

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RE: [Utah-astronomy] In the blue
by Kim Hyatt 17 Dec '03

17 Dec '03

Many magnitude estimates may have been made from plates taken specifically in blue light, such as those of the earlier Polomar survey. (Just a guess...) -----Original Message----- From: James Cobb [mailto:james@cobb.name] Sent: Wednesday, December 17, 2003 5:37 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] In the blue I believe he is referring to magnitudes obtained from black and white photography; it is biased toward blue light. Jim ---- Jim Cobb james(a)cobb.name On Dec 17, 2003, at 5:12 PM, Gibson, Jim wrote: I was just reading an article about the Herschel 400. The author Jay Reynolds Freeman made this statement: I have informally known for a long time that many older cataloged magnitudes of deep-sky objects systematically underestimate their brightness to the visual observer--the fact that many magnitudes were obtained in blue wavelengths guarantees that result... What does it mean "obtained in blue wavelengths "? How are magnitudes obtained in the blue wavelengths? Jim _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.utahastronomy.com

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In the blue
by Gibson, Jim 17 Dec '03

17 Dec '03

I was just reading an article about the Herschel 400. The author Jay Reynolds Freeman made this statement: I have informally known for a long time that many older cataloged magnitudes of deep-sky objects systematically underestimate their brightness to the visual observer--the fact that many magnitudes were obtained in blue wavelengths guarantees that result... What does it mean "obtained in blue wavelengths "? How are magnitudes obtained in the blue wavelengths? Jim

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RE: [Utah-astronomy] Disregard - Jim Test
by Gibson, Jim 17 Dec '03

17 Dec '03

Thanks Joe -----Original Message----- From: Joe Bauman [mailto:bau@desnews.com] Sent: Wednesday, December 17, 2003 2:24 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Disregard - Jim Test Yes! -- Joe

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Disregard - Jim Test
by Gibson, Jim 17 Dec '03

17 Dec '03

Did it work?

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Binocular C brackets
by Chuck Hards 17 Dec '03

17 Dec '03

Just before my accident, our own Jim Gibson located a generous length of 6" aluminum channel so I could make C brackets for list members. As soon as I can, I'll get them made, hopefully in January. Thanks to Jim, and thanks to all who have emailed to wish me well. The cast comes off this Friday and hopefully will stay off so I can start therapy. 2 fingers on my right hand are pretty attrophied and it's going to take some time & pain to bring them back, but the doc is optimistic, as am I. C. PS: Venus was stunning last night, did anyone else see it? __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/

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RE: [Utah-astronomy] PoleAlignMax
by Dale Hooper 16 Dec '03

16 Dec '03

Hi Don, Its my understanding that when you do the update to Maxim 3.21 you need to do it as a full install rather than as a minor upgrade. Otherwise, it won't install Pinpoint/LE and you'll get the message you received. Its also my understanding that if you download the Maxpoint demo that it will also install Pinpoint/LE on your system - which would still work after the demo expires. I had purchased the full Pinpoint, so I already had it. One other caveat that I seem to recall is that it may not include the Hubble Guide Star Catalog (GSC) (which for some reason NASA pulled off the web in October). If so, let me know and I'll see if its been posted somewhere else. If I can't find it then just send me a private email with your snail mail address and I'll burn you a CD with the GSC catalog. The USNO A2.0 catalog is still available for download - but it's 6 GB! I've already downloaded it so if there is interest I could make one copy of the USNO A2.0 that people could pass around (don't worry - it's legal <g>). Clear skies, Dale. > -----Original Message----- > From: Don J. Colton [mailto:djcolton@piol.com] > Sent: Tuesday, December 16, 2003 2:33 PM > To: Utah Astronomy > Subject: RE: [Utah-astronomy] PoleAlignMax > > > Dale > I have MaximDL/CCD's latest update but when I run PoleAlignMax I get a > message pinpoint is not installed and then the program comes > up. Will it > work or do I need some kind of plugin. > Clear Skies > Don Colton >

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