Clear Sky Continues

Nice Prominence Display

As mentioned in the previous blog, I spent several hours on the evening of September 15th capturing 233 individual images of various celestial objects. With much of my equipment left outside, I stumbled into bed at 1:40 AM on September 16th. Clear sky persisted into the morning of the 16th. I dragged myself out of bed after too few sleeping hours and went for a run. Then I hustled outside to image the morning Sun while good conditions continued. Equipment accumulated dew overnight which I dried off with towels. Mounting my solar telescope took less time than usual because more than half the equipment was already outside.

Not many dramatic sunspots were visible, but some nice prominences were displayed around the solar limb. The next image, a mosaic of the central disc, shows the only sunspots present. Sunspot 3433 is on the left. The other sunspot pair has small umbras. Spots 3434 on the left and 3429 on the right are connected by a white, energy emitting structure. A long dramatic dark filament stretches out in the upper right. (Click on images to enlarge.)

The following 11-panel mosaic, shows the relative lack of disc features.

Although disc features may have been sparse, there were a good number of prominences around the limb. Some are shown in the next mosaic which has been processed to reveal prominences.

An arched prominence appeared on the Sun's northern limb.

The southeastern limb had some spiky emissions from an emerging sunspot.

Finally, an enormous arching prominence with one explosive spike was displayed on the southwestern limb.

By the time this solar imaging session was over I was completely exhausted. Forecasts predicted cloudy skies for the next two weeks, so I appreciated the chance to take advantage of rare clear sky.
 

 

Starry Night

Success at Last!

Sky conditions were too good to pass up on the evening of September 15th! Humid, hazy, cloudy, summer air was finally replaced by cool, clear, dry, moonless sky! In addition, by some chance miracle, all five usually annoying neighbor spotlights were turned off most of the time. Of course, perfection is hard to attain. Light poured out from one neighbor's unshaded windows. This window light was easier to tolerate than glaring spotlights, however. So, all things considered, conditions were about as good as I can hope for in my backyard. This was a great opportunity to use my Nikon Z6 2 camera with a 130 mm Stellarvue refractor.

With temperature comfortably in the mid-60's I spent time setting up equipment and bringing the telescope mount up to speed. Eventually, all was ready. Sagittarius was getting lower in the southwest, so my first photographic target was the Lagoon Nebula (M8). The next image is a stack of thirty, 20-second exposures at ISO 6400. (Click on images to enlarge.)

For some reason the nebulosity has a purple color instead of being correctly red. Ten minutes of total exposure captured a good amount of glowing gas, and the background sky is reasonably black. The small golden clump to the left is NGC 6544, a globular cluster.

Next, I moved to another object in Sagittarius, the Eagle Nebula (M16). Once again, I stacked thirty, 20-second exposures at ISO 6400 to get the following image.

Nebulosity is inaccurately purple again. More exposure time is needed for this object. If you enlarge the image and look at the nebula center, you can just begin to see the "Pillars of Creation" made famous by the iconic Hubble Telescope image of the same name.

Now it was time to leave objects near the horizon and point the telescope closer to a darker zenith. The next image of Brocchi's Cluster, also known as "the Coathanger", came out particularly well!

The Coathanger's star colors are not quite as dramatically intense as some photos I've seen, but the asterism nicely fills the frame and shows up very nicely! I'm really happy with this picture, made from a stack of fifteen, 20-second exposures at ISO 6400. The small concentration of stars in the lower left corner is NGC 6802, an open cluster.

The beautiful color contrast double star, Albireo, is in the same neighborhood as Brocchi's Cluster. I moved there next. A 2X Barlow lens was required to produce significant separation between the pair which are only 34.9 arc seconds apart. The gold star is about 60 light years closer to Earth than the blue star, so they are a chance alignment rather than an orbiting pair.

The blue and gold star colors are only apparent on the outer fringes because star centers are overexposed. I should have realized this would happen for these bright stars. In this case, fifteen, 20-second stacked exposures was overkill! If I try this again, exposures shorter than 20-seconds would be better.

Large planetary nebula M27 was also relatively nearby. With a 2X Barlow lens fifteen, 20-second stacked exposures at ISO 51200 yielded the following image.

Twenty second exposures are the limit of my unguided mount before slight star trailing begins to show up with a 2X Barlow lens.

I removed the Barlow lens and captured the Double Cluster in Perseus by stacking thirty, 20-second exposures at ISO 6400.This image shows the clusters very well at full size, so click on the image to enlarge 100 percent. A few yellow stars are scattered about.

Finally, the constellation Andromeda had risen high enough for its famous galaxy, M31, to become a target. Unfortunately, stacking only thirty, 20-second exposures at ISO 6400 did not capture enough light to fully reveal the galaxy's outer arms. The outer arms and dust lanes are only partially visible in the next image. Their visibility may depend on properties of the device screen used for viewing as well as room lighting. M31's two companion galaxies M110 and M32 are visible. M110 is the larger companion below M31 and M32 is the smaller fuzzy spot above M31. The galaxy and its companions nicely fill the image frame.

Temperature had dropped to 58 degrees near 1:00 AM. My observing stamina has diminished with age. I was getting a bit chilly. After hauling the telescope and camera inside, I left other equipment outside so I could collapse, exhausted, into bed at 1:40 AM.