Apr 232017

Last night the SkySentinel meteor camera that I host here at the PTO caught sight of a set of sprites as a weather front approached from the northwest. Sprites are only one of several “Transient Luminous Events” associated with thunderstorms. Reports by pilots of ‘lightning’ above the clouds were once dismissed outright by meteorologists. Once directly imaged in 1989 and finally accepted by scientists as a real phenomenon, sprites and their relations have been recorded all over the planet as well as from the International Space Station. One estimate has several million of these high-altitude events occur each year.

North is at the top; northwest upper right.

These electrical discharges occur 50-90 kilometers above the ground. The sprites in this video are only visible on two frames. Look carefully and you will see the flash of ‘normal’ lightning reflecting off of low lying clouds immediately after the sprites.

 Posted by at 18:50
Apr 152017

I reconfigured the PTO with the planetary camera to get some pictures of Jupiter mid way through the 2017 apparition. My schedule, the full Moon and the weather finally allowed imaging on Thursday the 13th. The delay put Jupiter six days past opposition. However, the weather did more than delay the imaging session. It also cleaned and calmed down the atmosphere. During focusing it was apparent that the ‘seeing’ on Thursday made it one of the better nights. I don’t have a seeing monitor yet so I don’t have any empirical data to support that estimate, but it sure looked like one of the better nights.

Jupiter and Io

After a couple of quick test shots I set up to take a 60 second video every 10 minutes. This is one of the first in the series. It shows Jupiter and its closest large moon Io (eye-Oh).

According to Greek mythology Io was a mortal woman that the Roman god, Jupiter romanced. Once Juno, Jupiter’s wife, found out about the affair she turned Io into a cow.

Jupiter and no Io

The second image is about 2 hours 30 minutes later. Jupiter rotates one full revolution on its axis in 9 hours 55 minutes so the planet has, by now, noticeably rotated. Cloud formations on the left edge on the first image are now well right of center on the second. Also, by then, Io has continued on its orbit and moved off the right edge of the image.
Both of these images have been submitted to NASA’s JunoCam web page to support the Juno mission.

 Posted by at 12:57
Mar 022017

The UFO Galaxy (NGC 2683)[C:199x60s]

This galaxy may or may not be a barred spiral. There is evidence supporting a classical spiral as well as a barred spiral. The galaxy lies about 20 million light years distant in the Lynx constellation. Note the numerous dark dust lanes silhouetted against the combined light of billions of stars. The small spiral galaxy left of the galaxy’s core is PGC 2030408.

Chart generated with Cartes du Ciel

 Posted by at 00:22
Feb 202017

A quick check of the SkySentinel camera detections on Saturday night (the 18th) showed this bolide well to the west of the PTO. I checked the American Meteor Society web page the next morning and the fireball log showed an event (AMS 688-2017) at the approximate time with a list of 70+ reported observations. I am still working on posting my detections on the AMS video page, but am having problems. I think the problem is with the format of the videos created by the SkySentinel application.

 Posted by at 14:26
Feb 112017

Comet 45P’s motion over one day brought it above my treeline about an hour earlier than Thursday night. Unfortunately, the Moon’s daily motion brought it higher in the sky and closer to the comet. These combined to lessen the amount of time I could image the comet.

Honda-Mrkos-Pajdusakova (45P) [C:3x300s]

Thursday night the mount was tracking at the sidereal rate. This is the rate the Earth rotates using the stars as the reference. This is why the stars are round after a timed exposure.

An object’s orbit in the solar system can be accurately modeled by 6 numerical values known as orbital elements. Once enough observations of a solar system object are taken, those 6 values can be derived. The Minor Planet Center (MPC) publishes the orbital elements once they are calculated. In this case we are discussing comet 45P and depending on where the comet is in its orbit, the gravitational effects of other objects (say Jupiter or the Earth) can change its orbit and, as a result, the calculated orbital elements. These values can change fairly quickly. My first pointing attempt Friday night left me with an empty image of stars. With the comet nearing the Earth, the orbital elements from Thursday night were no longer accurate and I had to download Friday’s values.

By using the orbital elements published Friday I was able to change the rate and direction the mount moved to match the orbit of the comet. But since the mount is now matching the comet’s movement and not the Earth’s rotation, the stars get streaked. This is why the comet looks natural even though the exposures were 300 seconds long. The image is a stack of three 300 second images.

 Posted by at 17:29