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LPR Filters
by Chuck Hards 31 Jan '02

31 Jan '02

Expanding our discussion of color filters yesterday, It might be instructive to get the group's impressions of the various LPR (light-pollution reduction) filters we all use. I use an Orion 1.25" broadband, which I have found to be very useful on just about any emission nebula. Even galaxies and clusters benefit from it's contrast-enhancing ability, but to a lesser extent than emission nebula. I think I mentioned the other day that this filter does a good job of increasing contrast on Jovian features. Also in my arsenal is a Celestron narrowband filter, again 1.25". This filter is amazing on emission nebula and apertures larger than 4". At first I was annoyed when most of the dimmer stars in the field "dropped out", but the effect on the nebulae themselves more than outweighs this minor aesthetic effect. I have a Lumicon 2" broadband filter, bought as a "second" from Bill Vorce, due to a small coating flaw. Thus, I can't use it for photography, but it excells when used visually with low-power, 2" eyepieces. Interestingly, it provided excellent city views of comet Hyakutake and Hale-Bopp, when I couldn't get to a dark site. I have yet to find the LPR filter that works well enough on reflection nebula to justify the cost. Any leads would be appreciated. I also have a hard time justifying the cost of O-III & hydrogen-beta filters, due to the relatively few objects that they enhance. Were I to actually break down and buy one, I'd probably go with the O-III, since it can be used on planetaries. Many times I've used a broadband filter to help identify those "tiny blue dot" planetary nebulae, using the "flicker" method advocated by the late Walter Scott Houston. Saved time because with the filter, it isn't neccesary to examine every single star in the field at high power. They jump right out at you with the filter. I also have a pair of 7 x 50 binoculars that I have fitted with internally-mounted nebula filters. Several years ago, Orion had .965" filters on-sale for only $20 each. They threaded perfectly onto the internal ends of the eyepieces in this particular binocular. This instrument gives the binocular sky a whole new look! M42 & the entire "sword" is an amazing sight in this bino, as well as the area above the teapot of Sagittarius. I may have to try this with the 15 x 70's one day, although I'll have to use 1.25" filters for that bino, to avoid vignetting. Brent, I'm curious as to your feelings on these specialized filters. And everyone, please tell us what LPR filters you use, and how you like them. Thanks! Chuck __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

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More on Jupiter
by Patrick Wiggins 31 Jan '02

31 Jan '02

Here's an item that will be included in today's edition of News but since it was discussed here recently I thought I'd pass it on here first. Clear Skies! Patrick :-) All Eyes on Jupiter as Two Huge 'Hurricanes' Collide http://www.space.com/scienceastronomy/solarsystem/jupiter_storms_020131.html

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Jupiter activity
by Chuck Hards 30 Jan '02

30 Jan '02

For those who haven't heard about the white oval colliding with the GRS: http://www.skyandtelescope.com/news/news.shtml#Jupiterband Make sure the entire link is all on one line, or it may not work with some browsers. If it still isn't active, re-type it by hand. C. __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

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RE: [Utah-astronomy] The sky last evening
by David Dunn 30 Jan '02

30 Jan '02

I use #80A Medium Blue and #82A Light Blue for Jupiter and Saturn. The bring out the cloud bands and GRS on Jupiter and some bands on Saturn. #80A is usually the best because the planets are so bright. I use #25 Red and #21 Orange for Mars. I like the orange the best. They bring out surface detail. #80A brings out the polar caps on Mars. I use a moon filter for the Moon and Venus. It dims Venus enough that I can see the phase better. I haven't ever seen any detail on Venus. One Orions web page and in their catalog they give some suggested uses for each of the filters. I use this for a reference when I am observing. Dave -----Original Message----- From: Richard Tenney [mailto:retenney@yahoo.com] Sent: Wednesday, January 30, 2002 9:29 AM To: utah-astronomy(a)mailman.xmission.com Subject: Re: [Utah-astronomy] The sky last evening I would be interested (as a person not owning any filters yet) in knowing what the experienced planetary observers on the list recommend as far as color filters go for planetary viewing; what color(s) seem to work best for Jupiter? How about the other planets? -Rich --- Chuck Hards <chuckhards(a)yahoo.com> wrote: > Great report, Brent. Thanks! > > I'd like to emphasize that Brent used only 8" of > aperture for these spectacular views. I've had > similar views with my 6". You don't need a huge > aperture for great planetary viewing. > > Chuck > > > > __________________________________________________ > Do You Yahoo!? > Great stuff seeking new owners in Yahoo! Auctions! > http://auctions.yahoo.com > > _______________________________________________ > Utah-astronomy mailing list > Utah-astronomy(a)mailman.xmission.com > http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com _______________________________________________ Utah-astronomy mailing list Utah-astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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Fogbows
by Chuck Hards 30 Jan '02

30 Jan '02

I saw my first "fogbow" on the way to work this morning. The sun had just peeked over the mountain, and opposite it was a ghostly, white arch. It stayed opposite the sun as I drove north on I-215, so I knew it was a solar-related effect. I could detect no color at all. It was much too cold for fog droplets to be liquid, so perhaps it was not a true "fogbow", but an ice-crystal artifact. Chuck __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

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NASA Public Survey
by David Moulton 28 Jan '02

28 Jan '02

My apologies if this is a repeat on the list. I don't remember seeing it before. dave At the request of NASA, the National Research Council is conducting a planetary science community assessment of the priorities for the U.S. planetary research programs for the next 10 years. The Planetary Society has been asked to assist this "decadal survey" by seeking input from the general public about planetary exploration. Data must be input by January 31, 2002 to be counted on the survey. https://planetary.org/survey/ __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

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Jupiter
by Chuck Hards 25 Jan '02

25 Jan '02

Has anyone been watching Jupiter lately? Has the white oval collided with the GRS yet? Chuck __________________________________________________ Do You Yahoo!? Great stuff seeking new owners in Yahoo! Auctions! http://auctions.yahoo.com

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duplicate messages again
by Chuck Hards 22 Jan '02

22 Jan '02

Is anyone else getting duplicate messages, or is it just my email server? C. __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/

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Galileo, time
by Chuck Hards 22 Jan '02

22 Jan '02

I thought for sure that more people would have an opinion on where to scuttle the Galileo probe! Galileo is yesterday's news anymore, I suppose. On another matter, watching PBS recently, I noted that the designer of Mt. Rushmore allowed 3" extra material on the sculptures, to allow for 300,000 years of erosion. In other words, the sculpture will not acutually be finished for that lenght of time (assuming the erosion will be uniform, which I doubt). Even so, that is but the blink of an eye in terms of geologic (or cosmic) time....The show reinforced in my mind the notion that one day, the only remaining relics of mankind will be deep-space probes such as the Pioneers and Voyagers....everything here on earth is doomed to the slow but sure process of subduction, and eventual absorbtion & incineration by the elderly, red-giant stage sun. What we discard in the cold depths of interstellar space will be our only lasting legacy, enduring long after we have died out as a species. What's that, you say? We are not going to die out? OK, hold onto that thought if it makes you feel better. It's wrong, but hold onto it... Chuck __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/

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RE: [Utah-astronomy] Galileo, time
by David Dunn 22 Jan '02

22 Jan '02

I have read that when the Sun becomes a red giant it will push the Earth out to about Mars' orbit. When it finally blows off it's fuel and becomes a white dwarf, will all of the space junk orbitting the Earth become part of the nebula? Dave -----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Tuesday, January 22, 2002 10:40 AM To: Utah-Astro Subject: [Utah-astronomy] Galileo, time I thought for sure that more people would have an opinion on where to scuttle the Galileo probe! Galileo is yesterday's news anymore, I suppose. On another matter, watching PBS recently, I noted that the designer of Mt. Rushmore allowed 3" extra material on the sculptures, to allow for 300,000 years of erosion. In other words, the sculpture will not acutually be finished for that lenght of time (assuming the erosion will be uniform, which I doubt). Even so, that is but the blink of an eye in terms of geologic (or cosmic) time....The show reinforced in my mind the notion that one day, the only remaining relics of mankind will be deep-space probes such as the Pioneers and Voyagers....everything here on earth is doomed to the slow but sure process of subduction, and eventual absorbtion & incineration by the elderly, red-giant stage sun. What we discard in the cold depths of interstellar space will be our only lasting legacy, enduring long after we have died out as a species. What's that, you say? We are not going to die out? OK, hold onto that thought if it makes you feel better. It's wrong, but hold onto it... Chuck __________________________________________________ Do You Yahoo!? Send FREE video emails in Yahoo! Mail! http://promo.yahoo.com/videomail/ _______________________________________________ Utah-astronomy mailing list Utah-astronomy(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

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