Comet Updates

Comet C/2025 R2 (SWAN) continues to brighten but is still very low in the western sky. It has already passed perihelion and is now on its way out of the solar system. Recent observations put SWAN at magnitude 6.5 to 6.0, probably not visible with the unaided eye, but should be visible in binoculars and small telescopes.

Comet C/2025 A6 (Lemmon) is currently magnitude 6.0, and steadily brightening in the early morning sky. Look for it around 3:00 am in the morning due NE. Follow the three lower stars of the big dipper, and they should direct you to Lemmon, which will be about 10-15 degrees above the horizon. Expectations are still high that Lemmon will reach naked-eye visibility by mid-October. Because of its orbital position Lemmon can be seen both in the early morning hours and early evening hours around 7:00 - 7:30pm.

Comet Lemmon - October 5, 2025 - 3:00 am EDT

Special Presentation - Mysteries of the Cosmos - October 17, 2025

Special Presentation - October 17, 2025

Join us as we explore the universe with local astrophotographer and Westminster Astronomical Society member Michael J. Mangieri. Whether you’re curious about stars, galaxies, nebulae, supernovae, or black holes, this presentation will guide you through the celestial wonders that have fascinated humanity for centuries. Discover the mesmerizing diversity of galaxies. From majestic spirals adorned with radiant arms to enigmatic irregular shapes, each galaxy tells a cosmic tale. Peer into the heart of the Milky Way, our home galaxy, and unravel its secrets. What lies at the center? How do stars form in its spiral arms? Witness galactic collisions—a cosmic ballet where stars swirl and merge, forever altering their destinies.

Stars, those celestial beacons, ignite our night sky. Learn about their life cycles, from birth in stellar nurseries to fiery supernova finales. Explore the Hertzsprung-Russell diagram, where luminosity and temperature reveal stellar classes. Marvel at blue giants, red dwarfs, and everything in between. Gaze upon constellations—the ancient stories etched in star patterns. Orion, Cassiopeia, and Ursa Major beckon us to connect with the cosmos.

Michael will share his setup for astrophotography and his photographs too. Check out his work here: https://mdastro.com/

Outside viewing with a smaller refractor telescope and a larger 11” Edge Cassegrain will be available after the presentation, weather permitting. In case of cloudy weather, we will participate in a class exercise indoors.

Children ages 8 and up who can listen to our presentation are welcome to attend.

Registration is required (click here):   Natural History Society of Maryland - Unraveling the Mysteries of the Cosmos

Two Comets in the Same Sky! - October 2025

During the month of October, there will be not one, but two comets in the western sky. Although not unheard of, it is very rare for more than one bright comet to be visible in the same section of the sky at the same time. But next month, comets C/2025 A6 (Lemmon) and C/2025 R2 (SWAN) will be visible in the western sky about 30 minutes to an hour after sunset. Lemmon is expected to be the brighter of the two.

As seen in the diagram below, Lemmon (yellow path) moves from very low in the NW on Oct 11 to a more favorable position (20 degrees above the horizon) on the 21st. While comet SWAN (blue path) rises steeply from Oct 6 to Oct 21 and into November. 

SWAN will continue to rise high in the sky over the weeks to come, and although it will be decreasing in brightness a little bit (as it moves farther from the sun) it will be in dark skies and will remain visible with optical aid through November. Lemmon is in an orbit that limits its continued view for the northern hemisphere as it will start to sink lower in the sky soon after Oct 30. 

How bright will these be? That's a good question, and difficult to answer. Best estimates are looking good, however, especially for Lemmon.

On October 21st, comet Lemmon will be closest to Earth, very well placed in the sky and may reach magnitude 3.0, a very bright comet indeed! Anything under magnitude 6.0 is visible with the naked eye in good dark locations (brightness goes up as the magnitude number decreases). If it actually reaches that brightness it will be very easy to see with the unaided eye. On November 8th it reaches perihelion (closest to sun) and will be a little brighter but also lower in the sky. You'll need to view it 30 minutes after sunset (6:30pm). 

Comet Lemmon - October 21, 2025 - 7:20pm

Comet SWAN on the other hand remains at about magnitude 7.0 throughout its appearance. But it is a newly discovered comet, and the jury is still out on the magnitude estimates.

Comet SWAN - October 21, 2025 - 7:20pm

Binoculars will enhance the view for both of these and may be required to see comet SWAN. I'll post updates on or around October 5 when more data comes becomes available.

Titan's Shadow Transit

Once every 15 years, the orbital mechanics of the solar system brings the orbital path of Saturn's moon Titan into an edge-on alignment with Earth, opening a window during which the moon's colossal shadow can be spotted sweeping across the surface of the gas giant. There were three opportunities to capture this event starting in August (Aug 3, Aug 19, Sept 4) and then two more on Sept 20 and finally October 6 where the shadow can be seen just skimming the northern face of Saturn. 

The first three were clouded out at my location. I will be planning to see the Oct 6th one, but early this morning I was able to capture the event, albeit not very well. Seeing was pretty bad (it usually is at my site which is why I don't typically do any serious planetary imaging). 

Here is the sequence, from 1:08am to 2:58am. The dark spot at the top of the planet is Titan's shadow on the planet. It appears a bit elongated, due to its location on the planet, but also because Titan itself is very close to the shadow and resolution of the image couldn't separate the two, although you can see a hint of separation in the image on the bottom left. At top right is the simulation from Stellarium. 

Soldier's Delight Star Party - This Saturday, September 20, 2025 - 8:30pm

 

Soldiers Delight Star Party - September 20, 2025

Don't miss the next SD Star Party, where we will be discussing all things about the cosmos. Well, maybe not all, but lots! Stars, galaxies, black holes and dark matter. Join us this Saturday.

"Unraveling the Mysteries of the Cosmos"

Join us for an awe-inspiring exploration of the universe! Our host will guide you through the celestial wonders that have fascinated humanity for centuries. Discover the mesmerizing diversity of galaxies. From majestic spirals adorned with radiant arms to enigmatic irregular shapes, each galaxy tells a cosmic tale. Peer into the heart of the Milky Way, our home galaxy, and unravel its secrets. What lies at the center? How do stars form in its spiral arms? Witness galactic collisions—a cosmic ballet where stars swirl and merge, forever altering their destinies.

Stars, those celestial beacons, ignite our night sky. Learn about their life cycles, from birth in stellar nurseries to fiery supernova finales. Explore the Hertzsprung-Russell diagram, where luminosity and temperature reveal stellar classes. Marvel at blue giants, red dwarfs, and everything in between. Gaze upon constellations—the ancient stories etched in star patterns. Orion, Cassiopeia, and Ursa Major beckon us to connect with the cosmos.

From the fiery birth of stars to the cataclysmic demise of galaxies, the cosmos is a stage upon which an array of spectacular events unfolds. We will delve into the depths of space and time, encountering phenomena that challenge our understanding of the universe and ignite our imagination - the dazzling brilliance of supernovae, the dance of black holes and gravitational waves, pulsars and more. We will discuss how scientists study these phenomena and what they reveal about the nature of the universe.

Whether you’re a stargazing novice or an astrophysics enthusiast, this lecture promises wonder, knowledge, and cosmic camaraderie."

All ages welcome.

All programs rain or shine. Time machines will be provided by the Westminster Astronomy Club.

Activity: TBD

You can find out about special local events by contacting us at https://www.westminsterastro.org/

Date: Saturday, September 20, 2025

Time: 8:30 p.m. - 10:30 p.m. Eastern Daylight Time

Location: Soldiers Delight Environmental Area - Visitor Center

5100 Deer Park Rd.

Owings Mills, MD 21117

The Black Hole Nebula - LDN 323

Nestled within the Small Sagittarius Star Cloud, the Black Hole Nebula—formally known as Barnard 92 or LDN 323—appears as a haunting void in an otherwise star-rich field. This dark nebula, discovered by Edward Emerson Barnard in 1913, earned its nickname from its striking resemblance to a cosmic abyss, though it is not a black hole in the astrophysical sense. With an opacity rating of 6—the darkest on Barnard’s scale—it obscures background starlight with remarkable density, creating the illusion of a celestial shadow cast across the Milky Way.

LDN 323 (Black Hole Nebula)
August 11, 2025 - GT102/ASI533
26x120sec - 52min total integration time

Since I only collected 26 subs and limited the exposure to 120 sec (moon near full) I did not get as much of the rich star field behind B92 that I would have liked.

Telescope Maintenance Completed

It took about 8 hours total to do the mount and OTA maintenance. This included a complete cleaning and regreasing of both motor boxes and both RA and DEC axis worms and main gears. In addition, I added a new USB cable and cleaned up the wiring on the outside of the OTA.

A new PEC file was created using about an hour of acquisition time and 9 cycles of the worm gear using PemPro V3 (v3.10.09). Peak to peak after quadratic fitting was 6.5 arc seconds.

Analysis

Quadratic Fit (6.5 arc sec)

After loading the new PEC file to the mount and running the new analysis (3 worm cycles), the resultant peak to peak is now 0.65 arc seconds.

Corrected

This evening, I spent time (about an hour) collimating the OTA.

Here is a single 30 sec image of NGC 6811, and open cluster in Cygnus. Stars look perfect.

Later tonight I will be doing the final tests to see that the mount runs as smooth as possible. 

Mount Maintenance - have to do it!

Maintenance is crucial for all mechanical devices and needs to be done regularly. Telescope mounts are no exception. To keep that smooth, precise tracking functioning properly, you need to dedicate time to perform maintenance. 

But when? It seems like we always push it off until next week, next month, or even next year. Those clear nights are so rare, and you definitely don’t want your scope out of commission for any significant amount of time. But eventually it has to be done. And since I haven't done a re-grease since I've owned the mount (over 4 years) it's way overdue. So today was the day.

I ordered my re-grease kit from Astro-Physics on Friday and it arrived today (Sunday) by FedEx. Thanks AP!

After church, once the weather cleared up from the morning rain, I began the job. I removed the OTAs and stored them in my workshop. I then took out both motor boxes and managed to clean and regrease the Dec axis. As it was nearing 7:30 pm, I decided to finish the job tomorrow.

I'm also using this opportunity to add a new USB-C to USB-C cable for the replacement autofocuser on my GT-102. The new model, the ZWO EAF for 2025, features a USB-C connector, so the new cable was necessary to route through the mount.

Once I complete the re-grease and the new cable installation, I'll need a few hours with a reasonably clear sky to calibrate the mount and make sure everything is working OK.

New Comet on the Way

While sitting in my hotel room in Vancouver after a wonderful cruise to Alaska, reviewing my notes and information on my plans to photograph comet ATLAS (C/2025 K1) later this week I came across an announcement in SkyAndTelescope magazine that a new comet, potentially naked eye, is making its approach and will be well placed in October.

Colorful and diffuse, Comet Lemmon shines at around magnitude 10.8
and exhibits a short, spiky tail pointing northwest on August 25th.
Photo by Dan Bartlett

Comet Lemmon (C/2025 A6) has been brightening rapidly since early August and now glows at around magnitude 10.5. As reported in SkyAndTelescope, Lemmon was discovered during the Mount Lemmon Survey (part of the Catalina Sky Survey near Tucson, Arizona) this past January. It was initially thought to be a faint asteroid. Later, recovery images revealed a tiny coma, tagging it as a comet. In early August, after Lemmon emerged from the solar glow at dawn, it was a dim, 14th-magnitude mote. But it quickly brightened to 11 by month's end. Will it live up to expectations? Who knows. Like I always say: "comets do what they want, whenever they want".

Once I'm back home I will post details on this new comet, with star charts and detailed info on when and how to see it. Stay tuned!

Aurora at Alaska

During my cruise to Alaska, at the Princess Denali Lodge the skies were exceptionally clear (we had overcast skies and rain leading up to the stay at the lodge). but because I had a bad headache, I didn't go out during the clearest night they have had in weeks (I also forgot to have the lodge phone me if the aurora made an appearance). SO, the astronomer of our tour group missed out on a fairly nice aurora. I was a little upset that I had passed up this opportunity.

The next day I checked the weather forecast as it was overcast outside. There seemed to be a clear spot just south of us, small but rather persistent and moving north towards the lodge. I put in a request to be waken if the northern lights made an appearance - not likely, but I wasn't going to miss out this time.

At 2:10am I got the call. Joan and I went out and sure enough, there was a clear section of the northern sky. Some clouds were in the area, but the Aurora appeared and actually got stronger and stronger as the morning progressed. It was brighter than the night before and you could actually see the brighter green sections of the curtains with the naked eye. I got my photo!

A tiny nebula and the Milky Way's twin

On July 25 I took the opportunity to take advantage of some relatively clear skies (for a change) and point my scope to NGC 7331. The reason I picked this galaxy at this time is because a supernova was recently discovered very close to the nucleus of the galaxy (and because I wanted to compare my recent image of NGC 7331 with one I took back in 2017).

NGC 7331

Here is my latest image of NGC 7331.

NGC 7331 - July 25, 2025
EdgeHD11/ASI2600mm - LRGB - 3h 36m integration time

NGC 7331, often dubbed the “Milky Way’s twin,” is a striking unbarred spiral galaxy located about 40 million light-years away in the constellation Pegasus. With its elegant, moderately wound spiral arms and bright central bulge, this galaxy spans roughly 120,000 light-years, making it slightly larger than our own Milky Way. Viewed at a steep angle of 77 degrees, NGC 7331 presents a dramatic, elongated profile that reveals intricate dust lanes and a subtle asymmetry in its disk. Its core rotates in the opposite direction to the surrounding disk—a rare and intriguing feature. It is the brightest member of the Deer Lick Group.

The Deer Lick Group is an apparent galaxy grouping centered on NGC 7331. Surrounding it are several smaller galaxies—NGC 7335, NGC 7336, NGC 7337, and NGC 7340—that appear nearby in the sky but are actually much farther away, lying between 294 and 365 million light-years distant. This visual proximity is a result of line-of-sight alignment rather than gravitational association, rendering the “Deer Lick Group” a false group. Despite lacking physical interaction, the composition offers valuable insight into galactic structure, morphology, and scale.

Although a bit difficult to see the supernova, SN 2025rbs, is just to the right of the galaxy's central core. The image below, enhanced with high dynamic range (HDR) processing and cropped to show just the central core, shows the bright blue supernova glowing about as bright as the whole nucleus of the galaxy. 

SN 2025rbs was discovered on 14 July 2025 and it is a type Ia supernova. A supernova is a massive explosion that occurs when a star reaches the end of its life and can no longer hold itself together. In just a few moments, it releases an enormous amount of energy, briefly shining brighter than entire galaxies.

NGC 6210 - Turtle Nebula

NGC 6210, also known as the Turtle Nebula, is a striking planetary nebula located about 6,600 light-years away in the constellation Hercules. This cosmic sculpture marks the final breath of a sun-like star, which shed its outer layers to form a glowing shell of gas and dust. The nebula’s inner region resembles a delicate bluish “nautilus shell,” pierced by symmetrical jets of material streaming outward, while its fainter outer structure evokes the shape of a tortoise shell.

I'm not sure I see all the resemblance to a turtle but so be it.

NGC 6210 - The Turtle Nebula - July 4, 2025
EdgeHD11/ASI2600mm
LRGB - 1h 50m integration time

Although there is probably some significant Ha and Oiii signal in the object I chose not to capture that NB data since the broadband signal was so strong and I didn't want to spend the imaging time on this object.