Moon Picture

Moon picture taken August 20, 2013 at the Positively Pewaukee festival with a DSLR camera

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Jeff Annis demonstrated the Dobsonian telescope he built, at his May presentation for the Astronomy Club.



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Jupiter Picture from a Web Cam

Some of the best pictures of solar system objects are made by stacking frames from a web cam video. The picture of Jupiter below was made by stacking over 1,800 frames of video taken by a Stella Vue web cam at the Harken Observatory on September 5, 2010.







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What a lunar eclipse! (too bad it was cloudy)

As you might know, the weather did not cooperate for our planned observing session of the total lunar eclipse. What was also unusual was that this eclipse occurred on the night of the winter solstice (the longest night of the year for the northern hemisphere).   The last time both happened on the same day was on Dec. 21, 1638 and it won’t happen again until Dec. 21, 2094!   Fortunately, the telescope was streaming live eclipse images out on the web. I could not resist sacrificing a little sleep time and grab some screen images during the eclipse. Around totality, I grabbed a series of images. Using Registax 5 software, it was possible to stack these and enhance the detail in the images. The results were pretty cool. You probably have seen some of these on the web or in the newspaper but here is another for your enjoyment!

Clear Skies!
Randy B

Lunar eclipse images processed with Registax 5

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Geminid Meteor Shower – a warmer method to observe!

The Geminid meteor shower is about as good of a meteor show as the Perseids are but happens in the cold of winter. It peaked this year at about 2 AM on December 14th while the temperature was sub-zero. Being that cold and having to go into work the next morning, I thought that I would try an alternate observing method.

A Canon 300D (Rebel) DSLR camera has 6 megapixels and covers a 17 x 25 degree field of view with a 50mm lens stopped to f4. A 20 second exposure at ASA 800 will show stars to about the 8th or 9th magnitude without noticeable star streaking. The camera was connected up to a laptop to which each exposure was downloaded. The computer grabbed an image every 30 seconds for 6 hours while I slept. (The camera worked OK despite the cold) Continue reading

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HT Cassiopeia – Light Curve (Part 2)

The 600 images collected during the observing session were analyzed photometrically using the capabilities of the MAXIM DL5 software. There are numerous reference/comparison stars available for the analysis as shown on an AAVSO finder chart obtained at under the name HT Cas. Continue reading

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HT Cassiopeia – an Amazing Binary Star System (Part 1)

On November 2nd, a new AAVSO Special Notice (#221) arrived in my email inbox. HT Cas is a dwarf nova star in the constellation of Cassiopeia (the one that looks like a “W” and is currently well placed in our night sky).

This star infrequently has “outbursts” in its brightness. HT Cas actually is a binary star system with a red giant star as its companion. Material from the red giant is being pulled away by the gravity of the white dwarf forming an accretion disk. (read more about these at the following link: ) Continue reading

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Say Goodbye to Comet Hartley

As some of you may know, there has been another comet passing near the Earth on its periodic orbital path. It is known as a “short period” comet because it completes one orbit around the sun about every 6 years. Even so, it was not discovered until just 24 years ago. It went undetected for many years because it had not come closer to the sun than about 2 AU (astronomical units, 1 AU is an earth orbital distance). That has changed thanks to the influence of Jupiter. An article in the October 2010 issue of Sky and Telescope explained that 3 close passes to Jupiter in 1982, 1971 and 1947 have shifted Comet Hartley’s orbit closer to the sun. This time, it passed just 0.12 AU from the Earth on October 20th. It will reach perihelion (closest to the sun in its orbit) this week on the 28th. Continue reading

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A Whirlwind Tour of the Solar System

I received a phone call from Mike Paquette on Saturday July 24th. He told me that he thought that it might be possible to observe all of the planets in the solar system all in a few hours in one night! I was surprised to hear this. It seems to me that when things like this happen the media tends to “make a big deal” out of it. After all – how often does that ever happen (planets all visible I mean). A quick Google check found a headline in from 2004 pointing out that the five naked eye visible planets would all be visible in a line on 27 Mar 2004. It said that this would not happen again until 2036. Continue reading

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Fun with Astrometrics! and a Near Earth Object

As some of you may know, I have recently been experimenting with the capability of our observatory equipment to accurately measure the position of objects in the telescope camera images. Things outside of our solar system don’t change position much, but that still leaves hundreds of thousands of things to measure! These are the asteroids and comets within the solar system that orbit our sun.

The IAU (International Astronomical Union) Minor Planet Center has orbital information on 482419 objects. This includes almost 12,000 named asteroids and comets. Some which are of special interest to us here on Earth are the NEO or near Earth objects. Great efforts are being made to look for these and determine their orbits.

With the telescope and software at the Harken Observatory we can Continue reading

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