June 2006 - Utah-Astronomy - mailman.xmission.com

Trackball telescope
by Chuck Hards 18 Jun '06

18 Jun '06

In the August S&T there is an article on a trackball telescope. The author states that he is unaware of anyone else having come-up with the idea, but I am positive I have seen the concept prototyped and published somewhere else. I doubt it was S&T, as they should have caught that; it was probably ATM Journal or AA (the Tom Clark publication). I think the prior inventor did it with 4" or 6" optics. Can anyone help me pin it down? I'll try and dig out my old ATM journal issues in the next few days. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

1 0

RE: [Utah-astronomy] Vdb142 in Ha - The Elephants Trunk
by Tyler Allred 18 Jun '06

18 Jun '06

Chuck, No offense taken.... don't give it a second thought, Chuck. I, for one, am really glad that CCD technology and computers have made it possible to get nice images without some of the tedious aspects that once were the norm. Autoguiding certainly is easier on the eyes and neck than peering through a guiding eyepiece! Cheers, Tyler

2 1

RE: [Utah-astronomy] Vdb142 in Ha - The Elephants Trunk
by Tyler Allred 17 Jun '06

17 Jun '06

Chuck H. said: <Amateurs living today are extremely fortunate to have such capabilities available to anyone who is willing to spend the money on the equipment. It was not always so- well within living memory.> I may be a newcomer to this list, but I am not new to astronomy. I am 43 years old and I grew up with a Dad who was an avid astronomer. We started with homemade scopes and eventually worked up to a C-14 with a roll-off roof observatory. We tried some astrophotography (with limited success), but we mostly just enjoyed the views at the eyepiece. I am glad that I lived long enough to enjoy the convenience that CCD brings. It certainly is easier than the old days and produces generally better results, especially in the hands of an experienced imager. I might point out that CCD doesn't guarantee great results. I put enormous effort into my images. My entire setup is portable and needs to be set up and polar aligned each time I image. Also, the learning curve for processing data is pretty steep. If I gave my raw data to members of this list, few could produce really great images. It still takes a lot of work! But I love it!! Cheers, Tyler ________________________________ -----Original Message----- From: utah-astronomy-bounces+tylerallred=earthlink.net(a)mailman.xmission.com [mailto:utah-astronomy-bounces+tylerallred=earthlink.net@mailman.xmission.co m] On Behalf Of Chuck Hards Sent: Thursday, June 15, 2006 3:28 PM To: Utah Astronomy Subject: RE: [Utah-astronomy] Vdb142 in Ha - The Elephants Trunk When I was shooting astrophotos semi-regularly, there was no such thing as CCD's and autoguiders- I didn't have a choice. Everyone guided by eye and hand, and shot emulsion-based photograpy. It only seems monumental when one has the less-strenuous digital option available. BTW, when the very first imaging CCD's were used for astronomy, the hardware consisted of a single-line of sensors, not a grid. The image drifted across the line, which was really a type of scan. And sensitivity was terrible. Only bright objects could be imaged, and the resulting image looked more like a cartoon or painting than a photo. Images contained very little data compared to today's. Amateurs living today are extremely fortunate to have such capabilities available to anyone who is willing to spend the money on the equipment. It was not always so- well within living memory. --- Tyler Allred <tylerallred(a)earthlink.net> wrote: > A bit taxing!!!! You are a more dedicated soul than > me! :) I prefer CCD > and autoguiding, thank you. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ 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

2 1

RE: [Utah-astronomy] Vdb142 in Ha - The Elephants Trunk
by Tyler Allred 17 Jun '06

17 Jun '06

Canopus56 said: <In searching some catalogues and other net pictures, I don't see a reported surface brightness for this nebulae in integrated mag or surface brightness. Care to give an estimate?> I'm not really sure about an estimate, but I did identify a Mag 14.18 star and placed an image showing it at this link: http://tinyurl.com/foqam The star looks brighter than even the brightest areas of the nebulae, but I can't be sure. I would say it is probably Mag 15 or higher. <What's the filter factor on the Ha?> I am using a Schuler 15nm bandpass filter.... not a super narrow band. It passes approximately 90% of the Ha light but blocks nearly everything else. Cheers, Tyler

1 0

RE: [Utah-astronomy] Vdb142 in Ha - The Elephants Trunk
by Tyler Allred 16 Jun '06

16 Jun '06

Rob R said: <How did you determine that a stacked group of 20 minute exposures was the best for this image?? Is this something you know by experience w/ your system or interpolated from a reference set of exposure guides?? Or is this a value imposed by the G11 on autoguide??> Joe Bauman said: <Now that we're picking your well-stocked brain, can you talk a bit about stacking vs. long exposure? I understand that this beautiful view is a stack of several 20-minute shots. I assume a whole bunch of 20-minute pictures will still result in a final view that is not overexposed because what you're doing is eliminating noise. But 20 minutes still seems like a long exposure. I've had a galaxy overexpose in (I think) five or ten minutes. Is the nebula pretty dim? And just for discusison, what do you think a view of four hours, without stacking, would look like?> My response to these questions: - Exposure duration..... This object (Vdb142) is quite dim and doesn't have any really bright stars in the field. This combination allows longer exposure times, for the reasons outlined below. Also, remember that I was shooting with a narrow band filter that only allows a narrow range of light to pass. The Ha filter greatly reduces the total light reaching the chip. The exposure time for any object is best determined by looking at the histogram of an exposure to see if the stars are becoming saturated. If they are saturated (some pixels at maximum value), the image will have white stars instead of colored stars. The exposure can be shortened to the point where stars are nearing saturation, but not completely saturated. I intend to use this image as luminance data for an RGB image at a later date, so I didn't want to saturate the stars. I like star color in my images! Just to give you an idea of why I might use shorter exposures, here is a link to another image that I took the same night: http://tinyurl.com/qfdcv The M92 image is composed of 3 minute subs, because longer exposures would have overexposed the core area and washed out the star color. - The reason for multiple exposures.... Even though the noise from the chip in SBIG cameras is pretty low, it is clearly visible in any single frame, even a 20-minute exposure. Dark, bias, and flat frames can be used to remove much of the noise, but even after these are applied, noise is pretty apparent. However, when images are stacked and summed or averaged, the random noise tends to cancel itself out and the true signal remains. Images composited from several frames appear much smoother and subtle details emerge from the noise and become clear. Does that make sense? - What about a single long exposure... If I were to go four hours on a single exposure, several things would happen. First, all the brighter areas would become completely saturated, and any detail in those areas would be lost forever. It is impossible to regain detail in areas that are composed of a bunch of pixels that are maxed out. Also, the noise in a single image would be objectionable whereas the noise from 12, 20-minute images smoothes out beautifully! I hope this helps a little. Cheers, Tyler

4 4

Today's APOD is a "keeper" for a screen saver
by Canopus56 16 Jun '06

16 Jun '06

http://antwrp.gsfc.nasa.gov/apod/astropix.html A really good piece of space art. - Canopus56 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

1 0

Space weapons
by Chuck Hards 16 Jun '06

16 Jun '06

http://news.yahoo.com/s/nm/20060613/ts_nm/arms_space_usa_dc __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

6 18

News, 16 JUN 2006
by Patrick Wiggins 16 Jun '06

16 Jun '06

News, Friday, 16 June 2006 Surprise! John Gregory Visits SPOC Famed optician John Gregory (inventor of the Gregory-Maksutov optical design) was in Salt Lake yesterday on business and contacted the club about visiting SPOC. Unfortunately only a few SLAS members could be contacted on such short notice and even fewer could attend. But those that did reported Mr. Gregory was an fascinating guest and that they'd all had a great time. Pictures of the visit are temporarily at the following URL but have been submitted to the SLAS web site for possible permanent inclusion there. http://utahastro.info/temp/JOHNGREGORYATSPOC.HTML +++++ SPOC Update After weeks of waiting the cast bronze sign for SPOC's Refractor House finally arrived earlier this week and was mounted last night. See images 9 through 13 at: http://www.trilobyte.net/paw/slas/REFRACTORHOUSE05.HTML +++++ New Horizons Tracks an Asteroid It's a small object with big news for the New Horizons team: the first spacecraft to Pluto tested its tracking and imaging capabilities this week on asteroid 2002 JF56. http://pluto.jhuapl.edu/news_center/news/061506.htm +++++ NASA Astronomical Observatory Passes Hurdle The world's largest airborne astronomical observatory has passed a technical and programmatic review that could potentially lead to the continuation of the mission. http://www.nasa.gov/home/hqnews/2006/jun/HQ_06240_SOFIA_update.html +++++ Three new "Trojan" asteroids found sharing Neptune's orbit Washington, DC - Three new objects locked into roughly the same orbit as Neptune - called "Trojan" asteroids - have been found by researchers... http://www.carnegieinstitution.org/neptune_trojans/default.html +++++ Columbus delivered to KSC Listen to the podcast at: http://www.esa.int/SPECIALS/ESApod/SEMKC5AATME_0.html +++++ European Space Parliamentarians meet in Brussels Parliamentarians from 10 European countries met earlier this week in Brussels at the 8th European Interparliamentary Space Conference to discuss European space policy. http://www.esa.int/esaCP/SEMLHCAATME_index_0.html +++++ ************************************************** ************************************************** Images and Data From Cassini-Huygens At: http://saturn.jpl.nasa.gov/multimedia/images/latest/index.cfm http://saturn.jpl.nasa.gov/news/press-releases.cfm +++++ Information On The Mars Rovers At: http://marsrovers.jpl.nasa.gov/home/index.html +++++ SLAS 2006 Star Party Schedule http://users.wirelessbeehive.com/~paw/LOCAL.HTML +++++ SSA / UMNH 2006 Southern Utah Public Star Party Schedule http://users.wirelessbeehive.com/~paw/STARPARTIES.HTML +++++ ************************************************** News is being sent to you because of your affiliation with the Salt Lake Astronomical Society or because you asked to be subscribed. To unsubscribe please send your request to paw at wirelessbeehive dot com. Check out my NASA Solar System Ambassador web site at: http://www.umnh.utah.edu/utahsky and mirrored at http://users.wirelessbeehive.com/~paw/ For astronomy clubs in Utah see: http://users.wirelessbeehive.com/~paw/UTAHCLUBS.HTML For the Utah Astronomy Listserve see: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy ************************************************** -- Patrick Wiggins NASA Solar System Ambassador to Utah & NE Nevada paw at wirelessbeehive dot com http://www.umnh.utah.edu/utahsky http://users.wirelessbeehive.com/~paw/ 435.882.1209 801.918.9092

1 0

RE: [Utah-astronomy] Vdb142 in Ha - The Elephants Trunk
by Tyler Allred 15 Jun '06

15 Jun '06

Chuck said: < OK Tyler, so perhaps 12 twenty-minute exposures in one night would be a bit taxing- but it wouldn't take a man of steel. (Trust me, I've done it, and I'm hardly able to leap tall buildings in a single bound...of course, I was much younger then.) > A bit taxing!!!! You are a more dedicated soul than me! :) I prefer CCD and autoguiding, thank you. Cheers, Tyler

3 2

ISS crosses the Moon 6/15/2006 6:56 MDT
by Canopus56 15 Jun '06

15 Jun '06

Looks like this is still good for tomorrow morning. 6h56m52.60s ISS Crosses the disk of Moon. Separation=0.178Â° Position Angle=329.0Â° Angular Velocity=30.9'/s. Transit duration=0.79s Angular diameter=23.1" size=73.0m x 44.5m x 27.5m Satellite at Azimuth=209.3Â° SSW Altitude= 22.9Â° Distance=801.0 km Magnitude=-0.5mag Satellite apparently moves to clock-face direction 8:45 o'clock Closest Point Longitude=111Â°49'43" W Latitude=+40Â°47'29" Distance=6.17 km Azimuth= 48.6Â° NE Path direction: 138.6Â° SE ground speed: 7.615 km/s width: 19.2 km max. duration: 1.1 s Checking the centerline track out, it starts in downtown Bountiful and then runs over the foothills, and crosses Emigration Canyon Road below Ruth's Diner. The best observering point probably will be the This is the Place Monument or up in the northeast corner of Research Park. A cloud out is possible. The NOAA weather loop shows a front moving in, but not until after 8:00am. As Patrick noted, the Moon will be very low: 22 deg altitude at this time. Sunrise is at 4:56am. - Canopus56 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

2 6