August 2007 - Utah-Astronomy - mailman.xmission.com

Suppressing mirror flop in 10" GEM mounted Newt
by Kurt Fisher 13 Aug '07

13 Aug '07

As part of an ongoing project to minimize cone error in a GEM mount, for my 10" Newt I have things isolated down to mirror flop. You follow the flop rotating the scope from east to west RA and a Zhumell laser collimator. Does anyone have any recommendations on how to temporarily but safely suppress mirror flop in a 10" Orion Newt? I'm assume that the cell simply needs to be removed and the clasps holding the mirror in place tightened. On the otherhand, I understand that the free-flop movement is there to prevent stresses from building up in the mirror. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Perseids
by Kim 13 Aug '07

13 Aug '07

>From here in Sanpete I had a couple of pretty good hours of meteor watching. Beginning at 12:30 MST I made two one-hour counts. In the first hour I faced due east and observed 38 Perseids and 21 sporadic/non-shower meteors. In the next hour I faced directly toward the radiant and observed 54 Perseids and 14 others. About one-fourth of all meteors that I saw were 1st magnitude or brighter, and all of the bright shower members appeared blue-green. I forgot to take a reference chart with me to estimate limiting magnitude, but it was at least 6.8 or better, based on some stars in the square of Pegasus that I checked out at home. (There seemed to be a light haze as the sky wasn’t as clear as it had been earlier in the week.) The highlights were not shower members – I observed three very bright meteors, two of which were distinctly orangeish, one that occurred in Casseiopiea and Perseus (opposite direction to be a Perseid) and one in the southwestern sky. The third was in the west and had two distinct flashes before it burned up, no color. All in all, the best Perseid display that I’ve seen in years. If I wasn’t so tired I’d go back out. Anyone else see much? (I suspect that Patrick just wasn’t patient enough.) Kim No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.476 / Virus Database: 269.11.15/949 - Release Date: 8/12/2007 11:03 AM

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Re: Perseids
by Kurt Fisher 13 Aug '07

13 Aug '07

>From Little Mtn. between 12:30 and 1:30 pm looking at radiant saw 20, mag 1-2, 5-7 deg smoking streamers, all on radiant. This included 15 minutes blocked by fast moving high altitude clouds. Estimated crowd size within 2 kilometers of Little Mtn - 500-700 persons. - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Perseids, only so-so so far
by Patrick Wiggins 13 Aug '07

13 Aug '07

From out here in Stansbury up on my roof the show has not been all that great so far. From 01:05 to 01:35 I saw a total of 11 Perseids and one sporadic. However, 4 of the Perseids came within the last 5 minutes so hopefully things will be better when I climb back up there at 02:00. pw

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Re: [Utah-astronomy] Saturday night Perseids
by steve.nielsen＠comcast.net 12 Aug '07

12 Aug '07

We went up to a dark spot about 45 minutes east of Salt lake. I saw a spectacular one at 1:12 am about 30 degrees up from the horizon and staying at about that height. It lasted forever, 4 or 5 seconds, and was beautiful. Best I have ever seen. We didn't keep track but I will try to tonight. Seems like one every 5 minutes or so. Nice being out of the valley for a change. Is there a time tonight that is supposed to be the peak? -------------- Original message -------------- From: "Chuck Hards" <chuck.hards(a)gmail.com> > I settled back for an hour of dedicated watching last night from 2-3 am in > my backyard. Observed Perseids came at the rate of one every 5-7 minutes > which is phenomenol for a day ahead of the peak; I had ten total for the > hour. There were 2 @ mag. 2, most at about mag. 4-5. The brightest ones > produced streaks of 10-15 degrees, the dimmer ones considerably shorter. > One fairly bright one shot right down between Mars and the Pleiades, really > cool. I'm sure if I could have seen the entire sky at once, my total would > have been higher. Some surely got away unnoticed. > I was also impressed by the number of sporadics noted- I saw seven in that > period which is far higher than my usual random backyard rate. Seventeen > total meteors in an hour was a good show for a valley location. One > sporadic was a "reverse Perseid". It traveled a line almost directly toward > the radiant, an amusing surprise. > I've got to get up at 4 am Monday morning so I doubt that I'll do much > watching tonight, good luck to all who go for it. > _______________________________________________ > 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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Saturday night Perseids
by Chuck Hards 12 Aug '07

12 Aug '07

I settled back for an hour of dedicated watching last night from 2-3 am in my backyard. Observed Perseids came at the rate of one every 5-7 minutes which is phenomenol for a day ahead of the peak; I had ten total for the hour. There were 2 @ mag. 2, most at about mag. 4-5. The brightest ones produced streaks of 10-15 degrees, the dimmer ones considerably shorter. One fairly bright one shot right down between Mars and the Pleiades, really cool. I'm sure if I could have seen the entire sky at once, my total would have been higher. Some surely got away unnoticed. I was also impressed by the number of sporadics noted- I saw seven in that period which is far higher than my usual random backyard rate. Seventeen total meteors in an hour was a good show for a valley location. One sporadic was a "reverse Perseid". It traveled a line almost directly toward the radiant, an amusing surprise. I've got to get up at 4 am Monday morning so I doubt that I'll do much watching tonight, good luck to all who go for it.

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meteor activity Friday night
by Kurt Fisher 11 Aug '07

11 Aug '07

During a break on the tail end of a night of telescope observing, I spent a half-hour from 10:15-10:45 UTC on 8-11-2007 facing the Perseid radiant from Little Mtn to the north east. The Sky Quality Meter put the zlm at 20.4MPSAS or v5.8. The Perseus Double Cluster, the Cygnus Rift and the Andromeda Galaxy were all naked-eye. Typical for Utah summer nights, a light breeze kept seeing poor below 35 degs alt. I faced north-east with the Perseus radiant at about 40-50 degs altitude and a ninety-degree or 1/4 local horizon azimuth view. I sat in an astro-zen state of watchfull sleeping-deprived waiting. During the half-hour I saw 8 meteors in this part quadrant of the local horizon, all on Perseus radiant tracks, in a magnitude pattern of 4,3..3,2,2. Earlier in the evening around 5-6 UTC, I was using the telescope. About ten cars of family viewers came to Little Mtn for the night. As the Perseus radiant rose, the crowd gave two hurrahs, corresponding to bright horizontal traveling bolides. But I did not see these personally but was given a description by a general public visitor. The family groups left around midnight. Between 10:30UTC through leaving at 11:00 UTC, a diffuse zodical light could be seen in the northeast tracing the ecliptic plane between Gemini to 10 degs short of the Haydes moving group. - Kurt P.S. - I donot expect this to be a particularly great Perseid shower. The source comet is on its outbound leg and I expect we will have declining rates through the remainder of our lifetimes. But I still enjoy'em. _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Shuttle-ISS TV broadcast schedule
by Kurt Fisher 10 Aug '07

10 Aug '07

[From another newsgroup]. It looks like NASA is going to broadcast most of the crew activities live. I just spent about 10 minutes watching the blue marble Earth move underneath the orbiter (in one side of the frame). The station and orbiter are just starting to move into the terminator. Pretty cool stuff. See the schedule at: http://www.nasa.gov/multimedia/nasatv/mission_schedule.html You can view the broadcast over the internet on NASA-TV. http://www.nasa.gov/multimedia/nasatv/index.html It also appears you can grab a satellite signal directly, but not being a dish owner, I'm not sure how it works. NASA projects an ISS position screen every few minutes, but you can also see what terrain the station is flying over using the ISS tracking page at: http://spaceflight.nasa.gov/realdata/tracking/ - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Hargreaves Sturt part - Ball and Socket U-Joint
by Kurt Fisher 10 Aug '07

10 Aug '07

Is anyone planning on selling some similar truss parts at the Aug. 18 SLAS swap meet? - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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Llink between a supernova and mass extinction?
by Kurt Fisher 10 Aug '07

10 Aug '07

Julie, You might also be interested in the cover article in the March 2007 issue of Sky & Telescope ("Killer Blasts") on a related scenario of a nearby supernova being visible to proto-humans in the last few million years. Supernovae have long been known to be potential sterilizers for life within a few hundred parsecs around a detonation. Sciffy-types hypothesize that one reason E.T. hasn't contacted us is that in during the early formation of galaxies, there is more gas that creates more supernovae, effecting sterlizing the early Milky Way. Life didn't have a chance to take hold until the rate of supernovae declined. More recently, attention has turned to hypernovae that may sterilize life on kiloparsec scales. There are 3.26 light years to a parsec or about 3,200 light-years in a kiloparsec. In the last decade, there has been a great deal of research on the mysterious gamma ray bursts (GRBs) that permeate the night sky. Hypernovae are one of the suspected causes of GRBs. There are many potential causes for extinction events, for example, meteor impacts and volcanic-basaltic floods (volcanic flood fields two kilometers thick that are the size of Texas). Figuring out which cause triggered an extinction a few hundred million years after the event is a daunting challenge. It is a research area marked by heated debate. For example, although the Cretaceous extinction usually is attributed to meteor impact at the Chicxulub Crater in Mexico, but it is also associated with basaltic floods called the Deccan traps, now preserved in the Deccan Plateau in India. http://earth.jsc.nasa.gov/scripts/sseop/photo.pl?mission=STS057&roll=104&fr… Another more local example of a basaltic flood field is the Snake River plain in southern Idaho - just a few hours drive away. http://vulcan.wr.usgs.gov/Photo/NASA/AnnotatedImages/nasa_craters_moon_8410… That volcanic flood field is the brown "u" shape above Utah that you see on the weather map on the evening news. It is the dark grey horizontal bands of rock that you see along the highway in southern Idaho as your drive to Yellowstone or Boise. The Ordovician extinction is unique in that it is the only major extinction event that is not associated with a major basaltic flood. The news story and Melott's paper are in follow-up to his original 2003 theory that GRBs may cause major extinctions, and, in particular, the Ordovician extincition about 440 million years ago. http://www.arxiv.org/abs/astro-ph/0309415 The December paper discussed in the January 2007 MSN online article - http://www.arxiv.org/abs/astro-ph/0612660 and a more recent paper in May 2007 - http://www.arxiv.org/abs/0705.4274 - are all theoretical "what if a supernovae or GRB hypernovae blows up nearby" type papers. The GRB-extinction theory is still in an early development stage. To my limited understanding, no one has ever found any kind of trace signal of a GRB in the rock record - e.g. some kind of a chemical or mineral anomaly like the increase in iridium at the Cretaceous-Tertiary boundary that marks the Chicxulub Crater impact in Mexico about 60 million years ago. In theoretical modeling in their most recent May 2007 paper, Mellot and his student Thomas, conclude that eta Carinae, which everybody agrees could blow as a super- or hyper-novae anytime between tomorrow and the next million years - is too far at about 2.5 kiloparsecs to disrupt the Earth's environment. If eta Carinae it does go it will be a good show for amateur astronomers without any bad hang-over effects on good-old Gaia. http://hubblesite.org/newscenter/archive/releases/1996/23/image/a/ With Krubrick's _Dr. Strangelove_, I stopped worrying about the bomb. I ocassionally succumb to worrying about nearby nova or supernova progenitors going off. -:) With Mellot's new modeling paper, I'm going to clean-up my meteor-watching lawn chair and go out and start routing for eta Carinae to go - well like tomorrow. -:) - Kurt _______________________________________________ Sent via CSolutions - http://www.csolutions.net

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