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Tom Polakis
professor emeritus
Reged: 12/20/04
Posts: 551
Loc: Tempe, Arizona
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Yesterday, several of us looked at Jupiter during the day without optical aid. I had been looking at it just after sunset the previous day, so I know about where to point my telescope. After putting the scope on it, we looked through the Telrad, and there it was at 6:30 p.m.
The best time to look is in the last half hour before sunset. Here are the instructions for trying it from latitude 33 degrees north: start by looking due south about one-third of the way from the horizon to the zenith, and then move your gaze about half of this angle (15 degrees) to the left. The problem is focusing your eyes to infinity. Like the lens on my annoying old point-and-shoot camera, I just can't switch my eyes' auto-focus off. A polarizing filter darkens this part of the sky a lot. Alister Ling wrote about daytime Jupiter viewing here.
http://tech.groups.yahoo.com/group/amastro/message/4050
Tom
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Tom Polakis
Tempe, AZ
Visual observing, DSLR photography, lunar & planetary imaging
http://www.pbase.com/polakis/
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mikey cee
Carpal Tunnel
Reged: 01/18/07
Posts: 2330
Loc: bellevue ne.
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I've enjoyed this little "trick" for years. All of the brighter planets and Moon look much nicer near and just after sunset. I'm too lazy to try it after dawn but I would expect similar results. Chromatic aberation is a non issue with my big achros then also! Mike
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Mike 10x50 sears tower binocs, 3" f/10 edmunds reflector, 2.4" f/11.7 manon refractor, 6" f/8 jaegers refractor, "The 8 Ball" 8" f/13.3 brandt refractor, 3" f/15.8 sans&streiffe refractor, 3.1" f/15 selsi refractor(towa 339), 2.4" f/15 sears refractor, selsi 30x30mm spyglass, criterion 5-draw 25x45x75x spyglass(1957).
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astrokido
sage
Reged: 06/09/08
Posts: 274
Loc: Phoenix, AZ
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It's a fun challenge to follow some planets after sunrise, it's easiest for planet elongations of 60+ degrees. I find 10x25 binoculars a great tool for spotting them based on a general idea of their position, then viewing them without the binocs. Depending on air quality and other factors, some planets can sometimes be seen all day long. Without the binocs, it's almost impossible to find them. I'll have to try the polarizer method sometime, though polarizers work best at right angles to the sun.
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- Gill C. - All opinions subject to a speed limit of 299,792,458 m/s unless noted otherwise.
Nikon D40 Bushnell 10x25 Zhumell 20x80 Celestron Cometron CO-100 binochair CN gallery
skyatlas.rgbstore.com - free charts & more cool stuff
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Tony Flanders
Carpal Tunnel
Reged: 05/18/06
Posts: 2103
Loc: Cambridge, MA, USA
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Quote:
I've enjoyed this little "trick" for years. All of the brighter planets and Moon look much nicer near and just after sunset.
Actually, I don't agree. Mercury and Venus are famously best observed during broad daylight, but they have exceedingly high surface brightness. That makes them the exception rather than the rule. Also, Mercury and Venus are never high above the horizon in a dark sky. But the outer planets, when they appear biggest, are highest when the sky is dark.
Jupiter, my favorite planet, has rather low surface brightness and lots of subtle, low-contrast detail. I find that skyglow reduces the visible detail quite a lot even when the Sun is a few degrees below the horizon -- and much more so when the Sun is still in the sky.
By the end of astronomical twilight, however, Jupiter is probably as good as it's going to get, assuming that it's also reasonably high in the sky.
Of course, I'm using nice, clean, color-free reflectors  , so I don't have to worry about the color issues that plague big achromats.
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Tony Flanders
eyeglasses
6x15 and 8x32 monoculars
8x25, 7x35, 10x30 IS, 10x50, and 15x70 binoculars
70mm and 100mm achromatic refractors
4.5", 7", and 12.5" Dobs
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MessierScott
super member
Reged: 06/18/07
Posts: 188
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Just viewed it here at 6pm local time. I knew the exact spot to search though. Once I looked at something else and looked back, it took a few seconds for my eyes to register it again.
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Scott Kranz
20-inch f/4.3 Starmaster w/Zambuto mirror, Feathertouch focuser, GO TO & tracking
7-inch Starmaster
H-alpha Coronado PST
Denkmeier II binoviewers w/24mm Panoptics
16x80 binos
Astronomical Society of Kansas City
Astronomical League Messier, Meteor, Sunspotter, & Asteroid Observing Programs Coordinator
ASKC Dark Sky Site
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Bill Weir
scholastic sledgehammer
Reged: 06/01/04
Posts: 894
Loc: Metchosin (Victoria), Canada
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I've used Alister's technique to capture both Jupiter and Saturn after Sunrise. There are some tall trees to the east of my property that they would drift into so it was easy to plan the exact spot to look. The hardest planet to get naked eye before Sunset was Mercury. It took almost a week of planning and trying until I finally captured it 6 minutes before Sunset. I'm sure anyone driving by that field over that week must have thought I was a nutcase. It was a perfect location because there was this big barn I could align between the Sun and myself.
I've now seen 5 (OK, 6 with Earth) planets naked eye with the Sun above the horizon.
Bill
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6'' Orion SkyQuest
12.5'' f/5 Custom Truss Dob
William Optics 80mm ZenithStar II ED Doublet
f/5 25" newtonian on a giant GEM, any time I want
Observing sessions grand total for 2007, 171.
So far in 2008, 115
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DSalters
sage
Reged: 03/03/07
Posts: 438
Loc: High Ridge, MO (St. Louis)
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My two best Jupiter observations were during low-light just after sunset and just before sunrise. During these two times, I saw detail unlike ever before. Both observations were made using my 6" Dob.
Try this trick: Keeping an eye on Jupiter's moons after sunrise. This is easiest to do after sunrise because you already know where to look. They can be seen well after sunrise. I got tired of checking back and seeing them after 1/2 hour.
Daniel
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6" f/8 Bushnell Voyager Dob. Rebuild
10" f/5 Highe Dob. variant
(UNDER CONSTRUCTION: 5" f/5, 8" f/6, 13" f/4.6)
Baader Hyperions--Primary Eyepieces
"The sun has one kind of splendor, the moon another and the stars another; and star differs from star in splendor." -1 Corinthians 15:41
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HughB
journeyman
Reged: 12/28/07
Posts: 55
Loc: UK
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I'm fascinated that Jupiter is visible in the daytime here in the UK too. Give or take an hour, anywhere on the same latitude has the same night sky...
If you were to use optical aid... is there anybody, anywhere, that has something nice to say about using a filter? Planetary filters are easy to find on ebay etc, but I s'pose that tells it's own story!
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Naked Eyes
Enhanced Optics OEW (Open Eyes Wider)
4.5" Newt CheapScope (The Last Scope I Will Ever Buy)
Orion Optics UK OMC140 (The Very Last Scope I Will Ever Buy And This Time I Mean It)
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Tom Polakis
professor emeritus
Reged: 12/20/04
Posts: 551
Loc: Tempe, Arizona
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Quote:
If you were to use optical aid... is there anybody, anywhere, that has something nice to say about using a filter?
The best filter for daytime Jupiter sightings is a polarizer. Since your best chance for seeing Jupiter is when it is at its highest around sunset or sunrise, that places it about 90 degrees away from the sun. Rotate the polarizer correctly, and you'll be surprised at how dark that blue sky appears!
Tom
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Tom Polakis
Tempe, AZ
Visual observing, DSLR photography, lunar & planetary imaging
http://www.pbase.com/polakis/
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RandyR
Enginerd
Reged: 04/01/04
Posts: 14080
Loc: Castle Rock, CO 6677' MSL
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Not too long ago (a couple of years), I was able to spot (and point out to others) Jupiter at about 3 in the afternoon. Realize, here in Colorado we get some really clear skies some days, but when it's clear and Jup is bright, you can find it, if you know where to look. I use Cartes du Ceil a lot to figure out where it is... if you do, you can find the brighter planets pretty easily in daylight.
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"Dark Skies & Great Viewing"
RandyR / NQ0R
GPS 9.25 XLT/Sky Align /FeatherTouch
TV85 w/FeatherTouch
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