(Directions to these observatories can be found below on this page)
August 26, 2010 - General meeting of the PVAO at NNVC at 7:30 PM CDT Directions are below.
September 4, 2010 - Public observing at Sachtleben Observatory in Hastings at 9:00 PM CDT
September 6, 2010 - Public observing at Seven Hills Observatory at 9:00 PM CDT Directions can be found lower on this page. Go to www.7hillsobs.org for more information.
September 2010 - Free Public Planetarium Show at UNK in Kearney at 7:00 PM CDT For details see www.unk.edu/planetariumschedule Note: the date has not been posted yet. Check the link for an update.
September 18, 2010 - Public observing at Sachtleben Observatory in Hastings at 9:00 PM CDT
September 23, 2010 - General meeting of the PVAO at NNVC at 7:30 PM CDT Directions are below.
September 26, 2010 - Public observing at Seven Hills Observatory at 8:30 PM CDT Directions can be found lower on this page. Go to www.7hillsobs.org for more information.
Most general meetings of the PVAO are now being held at the Nebraska Nature and Visitors Center at 7:30 PM on the 4th Thursday of the month. . Click here for directions. We will observe if weather permits. Otherwise we will talk "shop" or entertain visitors with a video. The public is welcome!
The Turbulent Tale
of a Tiny Galaxy
by Trudy Bell and Dr. Tony Phillips
Next time you hike in the woods, pause at a babbling stream. Watch carefully how the water flows around rocks. After piling up in curved waves on the upstream side, like the bow wave in front of a motorboat, the water speeds around the rock, spilling into a riotous, turbulent wake downstream. Lightweight leaves or grass blades can get trapped in the wake, swirling round and round in little eddy currents that collect debris.
Astronomers have found something similar happening in the turbulent wake of a tiny galaxy that is plunging into a cluster of 1,500 galaxies in the constellation Virgo. In this case, however, instead of collecting grass and leaves, eddy currents in the little galaxy’s tail seem to be gathering gaseous material to make new stars.
"It's a fascinating case of turbulence [rather than gravity] trapping the gas, allowing it to become dense enough to form stars," says Janice A. Hester of the California Institute of Technology in Pasadena.
The tell-tale galaxy, designated IC 3418, is only a hundredth the size of the Milky Way and hardly stands out in visible light images of the busy Virgo Cluster. Astronomers realized it was interesting, however, when they looked at it using NASA's Galaxy Evolution Explorer satellite. "Ultraviolet images from the Galaxy Evolution Explorer revealed a long tail filled with clusters of massive, young stars," explains Hester.
Galaxies with spectacular tails have been seen before. Usually they are behemoths--large spiral galaxies colliding with one another in the crowded environment of a busy cluster. Tidal forces during the collision pull gas and stars of all ages out of these massive galaxies to form long tails. But in IC 3418, the tail has just young stars. No old stars.
"The lack of older stars was one tip-off that IC 3418's tail isn't tidal," says Hester. "Something else must be responsible for these stars"
Hester and eight coauthors published their findings in the June 10, 2010, issue of The Astrophysical Journal Letters. The team described the following scenario: IC 3418 is speeding toward the center of the Virgo cluster at 1,000 kilometers per second. The space between cluster galaxies is not empty; it is filled with a gaseous atmosphere of diffuse, hot hydrogen. Thus, like a bicyclist coasting downhill feels wind even on a calm day, IC 3418 experiences "a stiff wind" that sweeps interstellar gas right out of the little galaxy, said Hester--gas that trails far behind its galaxy in a choppy, twisting wake akin to the wake downstream of the rock in the babbling brook. Eddy currents swirling in the turbulent wake trap the gas, allowing it to become dense enough to form stars.
"Astronomers have long debated the importance of gravity vs. turbulence in star formation," Hester noted. "In IC 3418's tail, it's ALL turbulence."
To many astronomers, that's a surprising tale indeed.
See other surprising UV images from the Galaxy Evolution Explorer at http://www.galex.caltech.edu. Kids (and grownups) can play the challenging new Photon Pileup game at http://spaceplace.nasa.gov/en/kids/galex/photon/ .
Caption:
In the ultraviolet image on the left, from the Galaxy Evolution Explorer, galaxy IC 3418 leaves a turbulent star forming region in its wake. In the visible light image on the right (from the Sloan Digital Sky Survey), the wake with its new stars is not apparent.
The PVAO is blessed with some telescope parts and only needed a mount and some assembly to create at least one working telescope. This project was completed primarily by Richard Karohl. (Thanks Richard!) The scope will be available for loan to members who may not own a telescope or other educational purposes. If you are a prospective member and would like to borrow it , please contact us!
The PVAO will now be meeting at the Nebraska Nature and Visitors Center at the Alda exit of I-80 - west of Grand Island. It is a wonderful facility with plenty of room for guests and dark enough skies to allow observing right from the center when weather conditions allow. You can find out more about our new location by clicking here We will also be conducting occasional observing sessions in the cities of Kearney, Grand Island, and Hastings. Our meetings are novice friendly. Come on, check us out!
Jay Rasmussen has created a newly revised telescope primer. It's highly suggested reading for anyone interested in information on buying their first telescope. Click on the link below! If after reading this you have further questions, please contact us! You will need the Adobe Acrobat Reader available free from www.adobe.com
This is sometimes used to be our meeting location. Since we may do some special events at Rowe, the directions will remain here.
Exit I-80 at Gibbon Nebraska and turn south. Keep going until you cross both channels (both bridges) of the Platte River - this is a couple of miles. Just after passing the second bridge, you will see a dirt road which goes east - Elm Island Road. Go past it! The next road to the south will again be Elm Island Road. This time it only goes west - you will also see the Audubon sign. Take this one west! Take this road west until it turns south - a couple miles. Right at the turn to the south you will see the Audubon Center on the north side. You are there! You can reach the center by phone at (308) 468-5282.
The facility is located on Wabash Avenue three miles south of U.S. Highway 6. The Wabash Avenue turnoff is about one mile east of the Hwy 6/Hwy 281 intersection and is marked with signs to the observatory. If you're coming into Hastings from the north on 281, just go through town and take a left when you reach Hwy 6. The observatory is found on the left side of the street exactly three miles south of Hwy 6, just before the pavement ends. If you hit gravel road, you've gone too far!
For this year's complete observatory schedule of public viewings in adobe acrobat format (.pdf), click below. You can also view contact information in case the weather is doubtful. You will need the free Adobe Acrobat Viewer for this. You can download it at: adobe.com
To get to the observatory, proceed on I-80 to the Kearney interchange. Turn north - you will now be on 2nd Avenue. Take this all the way over the viaduct to Highway 30 (25th street). Turn west (left) - keep going past the university - all the way out of town where the road will narrow to 2 lanes. Once you have reached this point, go about 1 mile further to the Cottonmill Recreation Area Turnoff. Once there turn Right (it's the only way you can turn). Keep going past the lake entrance, the road will curve around, keep going. You will come down a large hill - keep going. You will PASS Cottonmill Estates. You will PASS the Cedar Hills sign. From this point go about 0.4 miles further until you see the green sign saying Ridge Line. Turn right there (it's the only way you can turn). Almost immediately the road will split. You will have a choice to go straight or break to the left. Break to the left! The observatory headquarters is the first house you will come to at the top of the hill. If you need further assistance, call 308-293-5776 or e-mail.
All current members are already subscribed. If you would like to join the club and wish to subscribe to the list or you are a current member, you can post messages to:
If you would like to subscribe to our listserv, all you really need to do is provide your e-mail address and click a submit button. You will be e-mailed a subscription confirmation request from "astronomy". When you are ready - click here.
Actually this listserv serves the needs for both the PVAO and the Kearney High School Physics II/Astronomy class. It will be good for both groups to share questions and information.
Feel free to use this listserv for any conversation involving club activities, astronomical discussion etc. It's there for you - use it!
Send comments to:
mark.urwiller@kearneypublic.orgMark Urwiller - Web Page Administrator
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