All Quiet on the Solar Front

 Solar System, Sun  No Responses »
Oct 292018
 

Yesterday, the daytime atmosphere proved to be quite stable. The video streams I took of the Sun were some of the best I have ever captured. Unfortunately, as far as the Sun was concerned, there wasn’t very much to look at. As we approach the next predicted solar minimum (2019-2020) in the Sun’s 11 year cycle the Sun presents fewer and fewer sunspots. As of today, the 29th, there have been 177 days without any sunspots visible at all. That’s more than half of the days so far this year. Yesterday was no exception.

Sun [(V)C:899x?ms]


The only visible break in the solar pattern were two very small filaments. The lower one persisted throughout the observing session. The upper one formed then dissipated within that time.
 

Sun (detail) [(V)C:899x?ms]

The images were taken through a Lunt 60mm H-Alpha scope using a Point Grey Flea3 camera. The imagery was captured with FireCapture and processed with AutoStakkert and Registax6.
 Posted by at 17:24

Wide Field Experimentation

 DSO, Wide FOV  No Responses »
Oct 232018
 

I am doing some wide field experimenting with my ancient and honored Nikon D50 DSLR. The images below were taken through a 18-55mm zoom lens, set at a focal length of 55mm. This generates a FOV of 25.7°x17.0° with each pixel representing 30.5″ of arc. The camera is mounted on a GEM (Losmandy G-11) to prevent long exposures smearing the stars.

I haven’t come up with a way to flat field these images yet which is why there are some dark splotches visible. These are known as dust donuts and are the result of dust or other material somewhere in the light path. Additionally, the camera was manually focused resulting in a soft look to the stars.

The first image is centered between the open star clusters Pleiades and Hyades. Most of the image is in the constellation Taurus. The bright star at the bottom right is the star Aldebaran. The ‘V’ shaped Hyades, the lower cluster, forms the head of the Bull with Aldebaran representing the eye. The orientation of this image is north to the left and east down and is slightly cropped to remove the tree line along the southern edge.

Taurus [M:17x60s] (mouse over for labels.)

The second image contains most of the constellation Orion. Visible in the ‘sword’ is the Orion nebula (M 42;NGC 1976) and just at the limit of visibility is a hint of the Flame nebula (NGC 2024) next to Alnitak. Curiously, M 42 is not identified in the annotated image. The orientation of this image is north up and east to the left.

Orion [M:30x60s] (mouse over for labels)

My next steps will be to try some different techniques to eliminate what appears to be some external reflections in the images and to add in the color. I like the scale of the image when the lens is set to 55mm and the optical distortion at the edge of the FOV is not as extreme as when the lens is set to a faster focal length. I think I will add this configuration to my list. I will also look for an affordable 50-55mm non-zoom lens.

 Posted by at 16:39

Moon

 Moon, Solar System  No Responses »
Oct 202018
 

Taken only two days from full, the only part of the Moon with any shadows are the limbs. This image is of the western limb centered on the crater Lohrmann. The 19 mile wide crater is circular but does not look it due to foreshortening. The crater lies between the crater Grimaldi to the south and Hevelius to the north. Most of the unlabeled craters are unnamed and identified by a letter associating it with a adjacent named crater. These are known as satellite craters or satellite features. For example, see Flamsteed T at the upper left of the image. Crater Flamsteed is well off the left edge.

Of note is the extensive fractured surface (rimae) inside and out of crater Hevelius.

Moon [(V)L:657×0.9ms] (mouse over for labels)

Crater Lohrmann is named for Wilhelm Gotthelf Lohrmann (1796 – 1840). Born in Dresden, he was a cartographer, astronomer and meteorologist. Using his own observations he started producing a set of lunar maps in 1821. Although completed in 1836 they were not published until 1878, well after his death. He is also honored by asteroid (4680) Lohrmann.

 Posted by at 12:02

Mars (Oct 16, 2018)

 Mars, Planet, Solar System  No Responses »
Oct 182018
 

Mars is now falling significantly behind us as the Earth continues its quicker orbit around the Sun. Although we will never see Mars in a crescent phase from our viewpoint, we have pulled far enough ahead to view Mars somewhat from the side. This is the reason Mars does not appear round in this image; we can now only see 86% of the daytime side of the planet.

Mars[(V)TR/TG/TB:1050×2.7ms]

Still no communication from our rover Opportunity. NASA reports that the Martian atmosphere at the rover’s location has returned to normal conditions. JPL is still hopeful that the rover can be recovered and they continue to listen and periodically transmit a “give us a call” command.

The matching map and orientation graphic are courtesy of WinJUPOS.

 Posted by at 11:25