Feb 102015
 

Everything about the Sun is huge: temperatures, pressures, size and mass. Even though we know those fairly accurately, the Sun can still surprise. Last October the Sun sported AR 2192, the largest sunspot grouping in the last 24 years. This week the Sun exhibits one of the longest filaments ever recorded.

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A filament is a portion of solar plasma that is suspended above the surface of the Sun by magnetic forces. Since it is being held above the surface it is slightly cooler making it appear darker. This one has been measured to be about 435,000 miles long. The Earth has a diameter of just under 8,000 miles and the distance from the Earth to the Moon is just under 239,000 miles. Those values put the length of the filament into perspective.

Right now, we view the filament from above. But as the Sun continues to rotate, the filament, if it survives long enough, will eventually be seen from the side. Once that happens the filament will become a prominence. A filament and a prominence are the same object, just viewed from different angles.

This image is a stack of 150 frames taken this afternoon through the PTO’s 60mm H-alpha telescope.

 Posted by at 22:42
Jan 312015
 

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The three major craters in the image above are Ptolemaeus (top center), Alphonsus (mid left) and Albategnius (bottom right). The image was taken on the 27th of January when these craters were just on the terminator. This places the Sun low on the lunar horizon. The low light angle accentuates shadows highlighting the Moon’s terrain. The image is a stack of 150 frames.

Ptolemaeus is named after the ancient astronomer and mathematician Claudius Ptolemy. Classified as a walled plain, the crater is about 95 miles in diameter and about 1.5 miles in depth. The crater has a smooth lava filled floor with one prominent sub-crater: Ammonius. Notice the depression just to the upper right of Ammonius. This is a pre-existing crater that was filled in when lava filled the primary crater. There are several visible in Ptolemaeus and are known as ghost craters.

Albategnius is named for the ancient Muslim astronomer known for refining the length of the year to 365 days, 5 hours, 46 minutes and 24 seconds. His calculation is only 2 minutes and 21 seconds shorter than that accepted now. The crater appears more damaged by additional impacts than Ptolemaeus, the most obvious being the 27 mile wide crater Klein that interrupts the rim of Albategnius. Both Albategnius and Klein exhibit a central peak where lunar material rebounded after impact.

Alphonsus also has a central peak. In fact, the tip of the central peak is just about all that is visible in the image with the majority of the crater deep in shadow. The central peak is about 4,900 feet high. One of the numerous sub-craters in Alphonsus is manmade. The 1965 NASA probe Ranger 9 impacted the crater floor after sending back more than 5,800 photographs.

 Posted by at 01:30
Jan 012015
 

Even though the clouds and near full Moon prevented any deep sky imaging this evening, together they provided the first image of 2015.

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In this case, the ring visible around the Moon is a 22⁰ halo formed by light refracting through randomly aligned hexagonal ice crystals. The phenomenon lasted well over 4 hours. This image is a single exposure by the NMSU All-Sky camera.

 Posted by at 22:31
Dec 202014
 

 
Once again the PTO archive provides this image. Often misidentified as the Little Dipper, The Pleiades (M-45) is an asterism in the constellation Taurus.

M 45
Since this cluster of stars is very bright and a very prominent group in the sky, it is featured in many of the world’s cultures’ literature and folklore.

  • To the Greeks the stars represent the ‘Seven Sisters’. These were the seven daughters of Atlas (a Titan) and Pleione (a sea-nymph).
  • To several Native American tribes the cluster was seven wives who husbands rejected them because they constantly ate onions. The wives ran away but once they were gone, the husbands relented. So now, the husbands (the Hyades cluster) forever chase after their wives (the Pleiades cluster).
  • The Japanese word for the cluster is “Subaru” and a stylized representation of the cluster is used as the emblem on the cars of the company of the same name.
  • The Bible mentions them 3 times in Amos 5:8; Job 9:9; and Job 38:31; for example:

Amos 5:8 – Seek him that maketh the seven stars and Orion…

This open star cluster is ‘only’ 100 million years old or so. But, compared to the estimated 4.5 billion year old Sun, this cluster is just an youngster. Analysis of the cluster shows an estimated 1,000 stars as members and it has an estimated distance of 444 Ly. The group does not have enough mass to remain gravitationally bound for long and is destined to slowly drift apart. At one time the nebulosity that is apparent in the image was thought to be the remains of the cloud of gas and dust that the stars were born in, but it is now known that the cloud is unrelated and the stars just happen to be passing through it.

Although the cluster is a small group, it is larger than my camera/telescope field of view. The image above is a mosaic of 4 different exposures combined to capture the entire asterism.

 Posted by at 09:17
Oct 232014
 

The PTO made its first road trip today to get a view of the partial solar eclipse visible from the panhandle. The tree line here at the observatory would not allow a view so I had to pack up everything and head to my favorite western horizon; the military drop zone just south of I-10.

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I had not used the new Point Grey camera with the Lunt H-Alpha scope before so some time was spent this morning in the driveway figuring out the correct configuration for the telescope / camera combination. A new voltage converter also made its debut to ensure the laptop wouldn’t stop mid eclipse and to power the camera. With so much equipment making its rookie start a dry run was in order. I wanted to make sure all the cables would reach where they needed to and that I brought along everything I would need. It was time well spent as all the bits and pieces were on hand, the cords and cables got where they needed to go and I was up and running and focused a good half hour before the estimated time of first contact. I also brought along a filtered Orion 4.5″ Starblast telescope so I could view the event in white-light and in case the spectacle drew any passers-by.

My plan was to start taking images 5 minutes before the eclipse started and get an image every 10 seconds from then until the celestial pair dropped below the distant tree line.

At least, that was the plan.

First deviation: timing. Luckily, my impatience took hold and I started the camera about 7 minutes early. First contact is just visible in image 4. Yep, between 30-40 seconds after I pushed the button.

And as always, Mother Nature marches to her own drummer and well before the tree line came into view, the Sun-Moon pairing dropped behind some distant clouds and the event was over.

The above image was taken just before the clouds made their entrance. This H-Alpha view does not give active region 2192 its due. The white-light view shows the largest sunspot complex that I have ever seen. The sunspot is large enough to view naked-eye with an old pair of eclipse glasses. Along with active region 2192 there are also two impressive filaments visible. Ultimately, I got 241 images before the clouds became objectionable. I will massage those into an animation and post it when finished. All the equipment played well together and there were no injuries. All-in-all a successful event.

Finally, I would like to thank one of our county’s finest. Just after the clouds started to intrude into the eclipse a patrol car passed by, saw the hood open on the van (remember the voltage converter), turned around and came back to make sure I didn’t need any help. Of course, I didn’t, but could have. Thank you Officer.

 Posted by at 22:25