More Star Clusters

Productive Seestar Session

A long period of clear autumn sky began on October 8th. That evening, after Seestar was set up outside in my backyard, I went inside to begin grabbing images for as long as I could stay awake. A good number were added to my Messier collection. When I quit after midnight, temperature had dropped to 53 degrees, and I had captured 14 images. Only four of the most interesting images are displayed below.

First is decent-sized globular cluster M12 in the constellation Ophiuchus. I've found10-minute exposures like this one work well for globular clusters.

I added open cluster M37 in Auriga to my Messier collection with the 5-minute exposure shown next.

I often discover attractive open clusters not included in the Messier catalog. For example, NGC663 in Cassiopeia is quite beautiful and shows nicely in the following 5-minute exposure.

Another example is open cluster NGC7789 in Cassiopeia. This cluster, also called Caroline's Rose, is incredibly rich. The next 5-minute exposure displays it well. It was discovered in 1783 by William Herschel's sister, Caroline, who was a very accomplished observer in her own right.

Why didn't Messier include the previous two clusters in his catalog? If he could observe M37 with his equipment, he should have been able to see NGC663 and NGC7789 as well. I don't know the explanation.

As this night ended I had added ten more Messier objects to my collection bringing my total to 71 out of 110.

Sunspots Before Aurora Display

Sunspots One Day Before Geomagnetic Storm

Months of cloudy weather finally ended enabling my first solar imaging session since July. Lovely cloudless skies continued for several days in early October. The following October 9th satellite view shows clear sky over Virginia, a good opportunity for solar observing.

Conditions were wonderful as I began imaging at 9:30 am EDT. It was 60 degrees under cloudless blue sky with no wind. When I quit one hour later, the temperature had risen to only 63 degrees. Seeing conditions were good, but not exceptional. Although the Sun displayed few dramatic prominences this day, several nice sunspots and filaments were spread across the solar disc as shown in the next 9-panel mosaic.

From left to right above are sunspots 3852 at lower left, 3849 and 3850 in the middle, and 3848 on top. Remnants of departing sunspot 3842 are on the right edge of the solar limb. (Click on the image to enlarge.) 

A few prominences can be seen on the limb when the mosaic above is processed differently. Enlargement also reveals some evidence of activity rising slightly above sunspot 3842 near the right limb.

Four major sunspots show good detail in the following 4-panel mosaic with 3848 at the top, 3849 and 3850 in the middle, and 3852 on the bottom left. The big filament to 3848's left was long lasting. Enlarge the image and notice a small eruption from 3852's umbra in the lower left corner.

Sunspot 3848's umbra looked like a Halloween skull! An X-class solar flare from this sunspot on October 8th produced the coronal mass ejection which caused the dramatic auroral display on October 10th. I wasn't lucky enough to capture that flare when I observed on October 9th. The image below was one day too late!

The next image's lower left shows a small white flare erupting above 3852's umbra at 9:37 am EDT.

With luck I won't have to wait another two months for an opportunity to use my solar telescope.

Aurora in Virginia!

Rare Light Show

Sitting in my living room on the evening of October 10th I began receiving numerous notifications about dramatic auroral activity. Normally, I ignore these alerts because the chance of seeing an aurora at my southeastern Virginia latitude of 37.4 degrees is very low. This time, however, an unusually big geomagnetic storm was predicted, so, just to check, I peeked outside at the northern horizon where I saw a dim red glow unlike the usual glow from light pollution. Next, I grabbed my phone and took a quick 2-second handheld exposure to check the aurora possibility. To my surprise I saw lots of red and even some green! So I rushed inside to tripod mount my Nikon Z6II. Nikon images quickly confirmed that an actual aurora was ongoing! Here's one of the first pictures I took at 10:31 pm EDT.

You can see hints of green on the right. The green faded quickly, however. I should have gone outside 30 minutes earlier. I suspect the green color was more intense then. You can see red becoming stronger relative to green in the next image taken one minute after the previous one.

Soon red became the dominant color covering most of the northeastern sky.

The light show steadily diminished. By 10:54 pm EDT the familiar curtain shape often seen in auroras appeared. 

Finally, by 11:34 pm EDT, most of the display had faded away. Only a dim red pillar was visible in the northeast running through the constellation Taurus.

The NOAA Space Weather Prediction Center produced the following forecast map for this October evening. 

Auroras over Canada were a sure thing according to this map, but not such a sure thing in Virginia. Auroras are very rare in Virginia. I've seen dramatic auroras in Iceland and Norway, but I've seen only one other aurora in Virginia since moving here 47 years ago. So it was a special thrill to see this limited light show from my backyard!

Star Clusters

Collecting Messier Objects

My ongoing quest to get Seestar images of all Messier objects took a big step forward recently. Every October seems to include a period of clear sky and mild autumn temperature, a welcome relief from months of steamy, cloudy summer nights. On October 5th there were no clouds, little moonlight, and only a couple temporary neighbor lights to interfere. I captured a good number of Messier star clusters to add to my collection.

Some open clusters are very pretty like M52 in Cassiopeia shown in the first image below, a 5-minute exposure. Note the small bit of red nebulosity at the top. This is the edge of the Bubble Nebula, NGC7635.

Another beautiful cluster in Cassiopeia is M103 shown next in a 3-minute exposure. Star colors here aren't as dramatically evident as I'd like. I don't know how to solve this color problem.

Open cluster M21 in Sagittarius is next. It's located near the beautiful Trifid Nebula, M20, partially visible at the bottom right of the following 3-minute exposure. I find M21's little circular loop of stars very attractive.

Probably the most famous open cluster of all is the Pleiades in the constellation, Taurus. A 20-minute exposure revealed some of the white reflection nebula lit by cluster stars. When I captured the next image the Pleiades happened to be oriented in just the right way to fall almost entirely within Seestar's limited field of view. This was a happy surprise!

Open cluster M34 in Perseus is a bit less striking than the previous clusters as you can see in the next 5-minute exposure.

The Messier catalog contains a couple of oddball members like the asterism M73 in Aquarius shown in the next 2-minute exposure. Perhaps the small group of four stars seemed like a fuzzy object in Messier's telescope? 

There are A LOT of globular clusters in the Messier catalog including a number of small unimpressive ones. If you've seen one of these unimpressive globulars, you've seen them all. So I'm not displaying all the globulars I captured this night, only the next two. First is globular cluster M10 in Ophiuchus. It has a good sized diameter in the following 10-minute exposure.

Globular cluster M30 in Capricornus appears smaller than M10. It has three short lines of stars pointing nearly towards its center. Each stellar line consists of three equally bright stars. These distinctive lines are visible in the next 10-minute exposure when you click on the image to view it at full size.

It took a 30-minute exposure to show inner parts of face-on spiral galaxy M74 in Pisces shown next. 

Finally, I attempted to capture a portion of the Heart Nebula, IC1805, in Cassiopeia. The entire nebula is too large to fit within Seestar's field of view, so I tried to include just the brightest portion. Even so, red nebulosity is barely visible in the next 30-minute exposure. Perhaps more would show up in darker skies and longer exposures.

I learned a valuable lesson during this Seestar session. Anticipating a long night, I used a charger cable and extension cord plugged into Seestar to keep the battery fully charged. I control Seestar from inside my house and was so lulled into indoor comfort I didn't check the cord status as I should have. After some time I noticed battery charge declining instead of remaining steady. When I went outside to see what was wrong I found the charging cord wrapped around Seestar several times like a boa constrictor! Fortunately, Seestar hadn't tipped over, but increasing cable tension had eventually broken the cord's USB connector and pulled it out of Seestar's USB port. I'll never make this mistake again! Seestar completes several complete rotations during a long night finding targets all over the sky. In the future I need to check outside more often.

I've now imaged 60 of the 110 Messier objects. As the October clear period continues I hope to increase the collection and post more images soon.
 

Roaming the Sky

Target Variety

 The sky was cloudless on September 10th and all five neighbors' spotlights were turned off. Although a nearly first quarter Moon hung in the south, clear conditions were too good to pass up. Forecasts predicted two upcoming cloudy weeks along with a brightening Moon, so I was motivated to take my Seestar outside for some imaging. There was no wind, and temperature ranged from the mid to low 60's.

I've decided to try capturing Seestar images of all 110 objects in the Messier catalog, so I began this night with some globular clusters and open clusters in Sagittarius, Scorpius, and Aquarius while the first quarter Moon continued getting lower in the sky. I've found 10-minute exposures work well for all globular images below. Globular cluster M28 had a relatively small apparent size and appeared among a crowded Sagittarius Milky Way star field in the first image below.

Also located in Sagittarius, dramatic globular cluster M55 is almost twice the apparent size of M28 and is nicely portrayed in the next image. 

The central portion of globular M2 in Aquarius seems burned out in the next image. (Click on images to get an enlarged view.)

The last member of this night's globular collection is M15 in Pegasus shown next. 

Open cluster M23 in Sagittarius features several interesting star chains and patterns in the next 5-minute exposure.

Pretty open cluster M6 in Scorpius, also known as the Butterfly Cluster, contains a couple colorful stars and an arrow-like grouping in the next image. M6 was very close to the horizon. I had to end the exposure after only one minute and 40 seconds because rooftops were beginning to show in the bottom of the image. I cropped rooftops out of this image.

While collecting the previous cluster images I came across dim galaxy NGC6822 with planetary nebula NGC6818 located nearby in the same field of view. This pair in the constellation Sagittarius are shown in the next 20-minute exposure. The galaxy, left of center, is barely visible above background noise. NGC6822, known as Barnard's Galaxy, was discovered in 1884 by Edward Emerson Barnard. It looks very similar to our own Milky Way galaxy's satellite, the Small Magellanic Cloud. Planetary nebula NGC6818, also known as the Little Gem Nebula, is the small blue-green object in the upper right hand corner. This nebula is too small to show any internal structure at Seestar's image scale.

Planetary nebula NGC 6818 in the previous image has an apparent angular diameter of only 22 X 15 arc seconds. Many planetary nebulae are similarly small and show up only as small blue-green circles in Seestar images. For example, NGC7662, the Blue Snowball Nebula in the constellation Andromeda, is about 30 arc seconds in diameter. It's the small blue-green circle near center of the next image, a 5-minute exposure.

Another example is planetary nebula NGC 7009 in Aquarius whose apparent size is about 30 X 25 arc seconds. This planetary is called the Saturn Nebula because its elongated shape in small telescopes slightly resembles Saturn's rings. Only a hint of this structure is visible in the next 5-minute exposure.

On the other hand, some planetary nebulae, like NGC1501 in Camelopardalis shown in the next 8-minute exposure, are large enough for Seestar to reveal internal structure. NGC1501 has a diameter of about 54 arc seconds. You can see the 14.5 magnitude central star when the image is viewed at full size.

My final planetary nebula for the night was the famous Ring Nebula, M57, in Lyra. Its apparent angular size is about 84 X 66 arc seconds, significantly larger than the previous examples above, so a 5-minute exposure reveals the ring shape and hints of red color.

Camelopardalis is an often overlooked northerly constellation recently featured in the October issue of  Sky and Telescope magazine. A suggested target there was open cluster NGC1502 which Seestar captured nicely in the following 5-minute exposure. Enlarge the image to see several close star pairs and a semicircular arc containing nine stars.

NGC281, the Pacman Nebula in Cassiopeia, was also well placed in the northern sky. The following 30-minute exposure taken with light pollution filter in place exhibits the Pacman mouth oriented upward. As usual with all my Seestar emission nebula images I find the red color dull compared to colors exhibited in more expert images.

I ran out of energy at 1:30 am and brought the dew dampened Seestar inside. At this point I've collected 45 out of the 110 Messier objects and look forward to capturing more in future months.

Smoke Clears

Nearly Perfect Conditions

September 2nd was the first night in several weeks without clouds, wildfire smoke, or a bright Moon. It was nice to see dark sky between stars instead of milky whiteness illuminated by moonlight. In addition, the 63 degree temperature was pleasant and wind was calm. Total perfection was too much to hope for, however. Four of my five light polluting neighbors had miraculously turned off all their troublesome spotlights. Only one remaining neighbor, the one next door, left one backyard spotlight on. Even though this annoying spotlight pointed away from my Seestar telescope, it lit almost the entire back of the neighbor's house. The glow of this reflected light ruined sky darkness toward the southern horizon where I had hoped to get images in the constellation Sagittarius.

My first target was a closely spaced galaxy group called Stephan's Quintet located near spiral galaxy NGC7331 in Pegasus. Stephan's Quintet turned out to be too small to show up well in Seestar's image scale, so I tried to center on larger NGC7331 instead and produced the first image below with a 20-minute exposure.

I should have taken more time to move NGC7331to the left because I might have captured tiny Stephan's Quintet in the same field of view. Nevertheless, there are at least six tiny dim fuzzy galaxies in the same image with NGC7331 which you can see labeled in the next image. (Click on the image to enlarge details.)

Next, I moved to the Helix Nebula, NGC7293, in Aquarius. This colorful planetary nebula showed up nicely in a 20-minute exposure with Seestar's nebular filter engaged. The colors seem kind of dull, however.

At this point Sagittarius was beginning to dip closer to the horizon, so I quickly tried to image some targets there. First, I took a 5-minute exposure of open star cluster M18 whose unimpressive portrait fills the next image's center. 

I also found open cluster M25 to be unspectacular as you can see in the next 5-minute exposure.

The previous two images required special processing to remove a glow in one corner coming from the spotlight reflection on my neighbor's house. With Sagittarius sinking I tried one more target, globular cluster M22. M22 looked nice in the following 10-minute exposure.

It was time to swing north from Sagittarius to Andromeda which had now risen high enough to put giant galaxy M31 in a good position for imaging. Since M31 is too large to fit entirely within Seestar's limited field of view, I hoped to create a mosaic by assembling three neighboring galaxy sections together into one complete image. Next are three separate 20-minute exposures moving across the galaxy in steps.

Unfortunately, Photoshop could not successfully merge all three previous images. Apparently, there was too much image rotation during the hour long period while exposures were taken. Also, inexplicably, the color of the first image in the series above did not match colors of the next two. I had partial success, however. Photoshop did manage to patch together the second pair of sections to produce the following nice two-panel mosaic.

M31's dark dust lanes show nicely in the previous mosaic. The two companion galaxies M110 (top) and bright compact M32 near the right edge also fit within the field of view.

At this point, more than four hours beyond my normal bedtime, fatigue was increasing. My final target was the Western Veil Nebula, NGC6960, in Cygnus. This segment of the larger Veil Nebula supernova remnant showed up well in the following 20-minute exposure made with the nebular filter engaged.

Now I ran out of gas! I quit imaging at 2:30 am and staggered off to bed. In the future I'd like to capture more separate pieces of the Veil Nebula. I'm also thinking of taking Seestar images of all objects in the Messier Catalog.