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Jan 102014
 

The first item listed in Charles Messier’s list of not comets is a supernova remnant in the constellation Taurus.  It was recorded by Arabic, Chinese and Japanese observers in 1054 and was visible in broad daylight.  It is 6500 light years away and by now has a diameter of 11 light years.  It is expanding at a rate of 3,355,404 mph.

The Crab Nebula (M 1) [L:30x30s;R:30x30s;G:30x30s;B:30x30s]

The Crab Nebula (M 1) [L:30x30s;R:30x30s;G:30x30s;B:30x30s]


I took a monochrome image of the nebula in 2009. That image is still in the image gallery. Since then a scientifically significant discovery has been made concerning M-1.

The nebula is one of the brightest high-energy sources in the sky. For 40+ years the X-ray energy emitted was considered steady enough to be used as a calibration target. In fact, it was steady enough to have a unit of measure defined based on its output. That unit, a Crab, may have to be re-visited as close examination of X-ray output using a newer more sensitive sensor has shown a totally unexpected variability. Data taken over two years show an intensity decline of about 7%.

 Posted by at 00:07
May 112013
 

The Pear Tree Observatory now has two meteor cameras standing watch. Our first camera, a Moonglow All-Sky camera, has been up and running since July of 2011. That camera is my go-to view of the sky during observing sessions. In the image below you can identify quite a few constellations and you can just make out the Milky Way. But as with all things there are trade-offs. In order to get an image that detailed the camera controller is designed to lengthen the exposure as the sky darkens. When the sky is as dark as it gets around here, the image update rate looks to be about a second and a half. And, as you can see, a lot can happen in that time. The meteor only shows up in one update of the video image.

MeteorDetect-6641_0_300

Since the meteor is only in one image its direction of motion cannot be determined. And in fact, can be misleading. In the video, the meteor appears to move from right to left. As the single image with the meteor is scanned on to the screen (from top to bottom) the right edge of the trail is first to be drawn. As the rest of the meteor trail is filled in, it appears to move to the left as the scanning proceeds down the frame.

Enter our new camera. While I was researching meteor cameras, I came across several organizations that sponsor meteor detection networks. New Mexico State University sponsors the All-Sky Camera Network. What started as a network of volunteer sites across the continental United States has now spread to several overseas sites as well.

The PTO sensor tree.

The PTO sensor tree.


 
 
The NMSU network web page has a map of their site locations and I couldn’t help but notice a gap over the panhandle of Florida. So in April of last year, I wrote to the listed contact. The response was there were no cameras currently on hand, but I could go on a waiting list should another batch be constructed. I said “Sign me up.” and in November received an email saying another batch of cameras was ready and was I still interested? A little more than a week later a box arrived with the camera and documentation inside.

The NMSU all sky camera in it's PVC housing.  The Moonglow camera is to the right in the background.

The NMSU all sky camera in it’s PVC housing. The Moonglow camera is to the right in the background.


 
 
 
 
It took me a while to construct the brackets necessary to mount the camera, and even more time matching the operating parameters to our sky conditions, but it is now operational. And based on the results of the recent Eta Aquarid meteor shower, it works very well. The system uploads each nights activity to a server at NMSU where the data are processed and cataloged. The videos are then posted on the web page. The PTO captures are posted here.
 
 
 
The only detection by the Moonglow camera was the single frame on the 6th of May shown above. As you can see from the archived videos on the NMSU web page their camera detected 5 meteors on the 6th, 7 on the 7th and 5 on the 8th.
 
 
j20130506_091415_494
But once again, compromises are made. The NMSU camera does not appear to lengthen its exposure time which means more frames are captured in the same time span. This also means that only the very brightest stars are visible and then just barely and the Milky Way is not visible at all. The video that matches the detection by the Moonglow camera shows the meteor travels left to right with a slight flare near the end.
 
 
Both cameras are valuable assets of the observatory. Each has been optimized for a specific task and both perform those tasks very well.
 Posted by at 00:49
Apr 102013
 

It is not unusual to see grand spiral designs from inside the dome of the Pear Tree Observatory.  I took this image of NGC 3938 on the 1st of March this year.  Located in the constellation of Ursa Major, this spiral is located approximately 43 million light years away. With a diameter of 67,000 LYs it is about 2/3rds the diameter of the Milky Way galaxy. 

[C:30x120s]

What is unusual is to see a grand spiral design inside the dome of the Pear Tree Observatory.  Although the direction of rotation is opposite and the difference in scale is astronomical,  the pattern is unmistakable.  Obviously, some insect found the environment inviting just under the lip of the rotating portion of the dome.  The eggs sit on top of individual stalks each about three sixteenths of an inch high.  The diameter of this spiral is about the same as a nickel.  My guess is the  temperature in the uninsulated dome doomed the eggs as they have not hatched after several months. 

 

 Posted by at 22:49
Oct 292012
 

This showed up on the All-Sky camera this morning. The path and brightness is amazing similar to the meteor captured four months ago on the 29th of June.

29th of June. 29th of October. Hmmmm…

[youtubegallery]

[/youtubegallery]

Air Force base just west of here with a very long runway. Hmmmm…

If we capture another ‘meteor’ on the 1st of March we will have to revisit this.

 Posted by at 22:01
Oct 072012
 

This image is a small portion of IC 5067. The entire nebula has the popular name “The Pelican Nebula”. The field of view of my telescope/camera combination is not large enough to see the whole nebula. If you could see the entire nebula and hold the picture just right and squint your eyes, maybe you can see a pelican in there somewhere.

“The Pelican Nebula” (IC 5067) [C:47x60s]

The nebula is located in the northern constellation Cygnus (The Swan) and is about 1800 light years away.  The bright star on the lower left is 56 Cygni.  At a magnitude 5.05 the star is visible to the naked eye just east of Alpha Cygni.  Alpha, also known as Deneb, is the star that denotes the tail of the in-flight swan.  The nebula is a large area of ionized atomic hydrogen (an H II region). Recently formed stars excite the hydrogen to glow. They also shape the glowing gas into the fanciful shapes that are visible.

This photo is a stack of 47 sixty second images.

 Posted by at 21:36