May 2011 - Utah-Astronomy - mailman.xmission.com

Re: [Utah-astronomy] Four-Planet Dance of 2011
by Canopus56 01 May '11

01 May '11

Day One Dance of the Planets Image http://www.slas.us/gallery2/main.php?g2_itemId=4229 Only Venus and the Moon were visible this morning. Basically, through May 7 or 8, Jupiter will be too close to the Sun for decent imaging. The cut-off criteria is that the Sun is more than 6 degrees below the true horizon on Jupiter's rise. The apparent movements of Venus and Jupiter during the month are as follows. From the 1st to the 8th, the angular distance between Jupiter and the Sun is increasing but Jupiter's position does not change on the celestial sphere. This results in Jupiter becoming visible and ``imagible'' after the 7th with improving circumstances through the end of the month. The apparent motion of Venus will be that it appears to move along the horizon from south to north from May 1 to May 17. Venus rises first from the 1st to the 8th of May; the two planets are in within one degree from May 8th to May 11th; but then Jupiter rises first through the rest of the month. Column JupImagWindowMins in the appended ephemeris table means the number of minutes after Jupiter rise before Sun reaches -6 degs below true horizon. Nautical twilight is adopted as the imaging limit due to increasing sky brightness as civil daylight rapidly approaches. This criteria choice was made based on a series of images taken on the morning of May 1st. The window for imaging Jupiter (using this criteria) opens on May 7 and continues with an improving trend until May 17. After May 17, Venus will be more than 5 degrees from Jupiter along the eastern horizon. Two other planets - Mercury and Mars - will all be within five degrees of Jupiter between May 8 and May 17. However, sky brightness will probably prevent imaging of those lower magnitude planets. Both Venus and Jupiter will have magnitudes above -1.0; Mars and Mercury are fainter than 1 magnitude. >From May 1 to May 8, the column MDT-Rise-Venus+Offset is my best estimate for when to begin imaging from Lt Mtn. The window closes after the sum of the MDT-Rise-Jupiter+Offset plus the imaging window value JupImagWindowMins. As an example for May 5, the start time is 5:44:00 AM (Venus rises over the east ridge) and ends at 5:58:00 AM (Jupiter rises over the east ridge plus 2 minutes before the Sun washes the sky out). After May 8, Jupiter rises first. For May 12, the start time of the imaging window is 5:32AM (Jupiter rises) and the end of the imaging window is 5:39AM - when the Sun is at -6 degrees below the horizon and just 2 minutes after when Venus rises. The last column, AZ-JupiterCoRise, gives the azimuth of the first rising planet is the best place to point your camera. An easy guide to finding the az on the horizon is to mentally draw a line between alf And and gam Peg (the easterly stars of the Pegasus square), divide the line in half, and then drop a perpendicular line to the horizon. That is at about 82 degs az. Clear Skies - Kurt Vertical character separated table for import into Excel Table is particular to Little Mtn Utah Day | DayofWeek | MDT-Rise-Venus+Offset | MDT-Rise-Jupiter+Offset | DistVenusJupiterDegs | JupImagWindowMins | AZ-JupiterCoRise 01 | (Sun) | 5:48:00 AM | 6:09:00 AM | 01.0 | -8.4 | 83 05 | (Thu) | 5:44:00 AM | 5:56:00 AM | 02.1 | -3.2 | 86 07 | (Sat) | 5:42:00 AM | 5:49:00 AM | 01.2 | 0.00 | 86 08 | (Sun) | 5:41:00 AM | 5:45:00 AM | 00.9 | 1.60 | 86 10 | (Tue) | 5:39:00 AM | 5:39:00 AM | 01.0 | 4.00 | 82 12 | (Thu) | 5:37:00 AM | 5:32:00 AM | 00.5 | 6.80 | 82 15 | (Sun) | 5:34:00 AM | 5:22:00 AM | 03.1 | 11.2 | 83 17 | (Tue) | 5:32:00 AM | 5:15:00 AM | 04.9 | 14.0 | 84 20 | (Fri) | 5:30:00 AM | 5:05:00 AM | 07.4 | 18.0 | 85 25 | (Wed) | 5:26:00 AM | 4:48:00 AM | 11.8 | 25.2 | 86 30 | (Mon) | 5:23:00 AM | 4:31:00 AM | 16.2 | 32.0 | 88 Day - Day number in May DayofWeek - Monday to Sunday MDT-Rise-Venus+Offset - Horizon rise time plus 23 minutes to clear mountain ridges at Little Mtn Utah MDT-Rise-Jupiter+Offset - Horizon rise time plus 23 minutes to clear mountain ridges at Little Mtn Utah DistVenusJupiterDegs - Number of degrees between Jupiter and Venus JupImagWindowMins - Number of minutes after Jupiter rise before Sun reaches -6 degs below true horizon - Imaging limit AZ-JupiterCoRise - Azimuth where either Jupiter or Venus first rises over the ridgeline east of Little Mtn Utah

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Same deal with me Chuck, minus the RX-8 stuff
by Dave Gary 01 May '11

01 May '11

Chuck, Work, work, work....I don‘t do anything else. Get up at 4am? I’m there by 4am. Ten to twelve hours a day. Same crap, different day. I have my telescope on a dolly and wheel it out of the garage on the nights I have enough gumption to do it. During this time of year I can’t view at all on a workday. It doesn’t get dark until 9pm and I have to get up at 3am. When I put the wieners out in the morning (they get up when I get up) the sky sure looks nice. I read quite a bit. Science, mostly. I’ve built quite a library over the years. Read at work when it gets slow. I don’t think the boss likes it that much but I’ve never been late or sick in over 30 years so I guess he could do worse. Therefore, I peg reading as a hobby. Oh, and cleaning my pool every single day like a serf. Word of advice; never, ever, get a pool unless it’s covered or you have serf to clean it. I’m not complaining (well, maybe the pool) and the funny thing is when I’m not at work I’m, usually, damned bored. I’m going to the ALCON festivities (we serfs plan ahead for the big events) so, maybe, I’ll see you there. Which do you prefer, Maker’s 46 or Crown Royal? Dave

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Thank you
by Mark Shelton 01 May '11

01 May '11

Thank you all for the information and advice on my Dob project. It is nice to know when you need advice....... there are people willing to help. Mark

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Same deal with me Chuck, minus the RX-8 stuff
by stormcrow60＠xmission.com 01 May '11

01 May '11

Dave wrote: "When I put the wieners out in the morning (they get up when I get up) the sky sure looks nice." Hahaha! Funny! Jon

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