I wasn't going to do it. I was sure the sky would be cloudy and the sunspot gone. Today, however, I could see Sun (sort of) so I had to try. Seeing conditions were not poor, they were bad. The atmosphere was stirred up and clouds were present -- at times blocking the view entirely. So, with all of those qualifiers, here is our best effort recording departing sunspot AR4366 -- weakening but reportedly still issuing flares -- and a couple of its companions.

#sunspots #solarastronomy

APOD: 2026 January 13 – A Solar Eruption from SDO
https://apod.nasa.gov/apod/ap260113.html

#Astronomy #SolarAstronomy #APOD

APOD: 2026 January 13 – A Solar Eruption from SDO

A different astronomy and space science related image is featured each day, along with a brief explanation.

Although seeing conditions weren't the best, today offered the first opportunity in quite some time for us to see Sun! Shooting between passing clouds, with our DSLR rig, we visually observed the expansive train of sunspots in the southern Solar hemisphere. For all of its impressive size, the enormous sunspot complex remains quiescent -- despite its potential for X-Class flares! 1/2

#sunspots #sun #astronomy #solarastronomy #spaceweather

Were We Wrong About the Solar Cycles? NASA Reports Extreme Activity Nobody Expected - YouTube
https://www.youtube.com/watch?v=hxgS9aR1bkU

#Astronomy #SolarAstronomy #Sun

Were We Wrong About the Solar Cycles? NASA Reports Extreme Activity Nobody Expected

YouTube
Spatially resolved slit spectra of a sunspot. Swedish solar telescope. #physics #solarastronomy #spectroscopy.

Sun in a Different Light

Our neighborhood star: The Sun. Photographed in hydrogen-alpha light, this image shows the roiling chromosphere of our star with a large filament parallel with the left-hand edge of the picture, sunspots strung vertically across the center, and a good number of prominences along the rim, glowing against the dark background of space. Image has been rotated — east is up, north is right. Imaged 2024-10-26. 18:43 UTC. Credit: James Guilford, Stella-Luna Observatory

White light allows viewing Sun as if we could stare directly at it without the resulting blindness. The Herschel wedge does much the same thing but with, perhaps, a bit more contrast and detail. Both of those white light views allow us to see a layer of the solar atmosphere called the photosphere. In the photosphere the most apparent details are sunspots, standing black against a white background. With enough resolution we can also see granulation — enormous convective bubbles of searing solar plasma.

One layer above the photosphere — yes, above — is the chromosphere. Shining in the wavelength of hydrogen-alpha (Ha), the chromosphere is not visible to us without light filters that exclude all light but Ha. A wholly different view of our Sun is available in that wavelength. Swirling seas of plasma form curves and hash as they are moved by magnetic fields, long filaments float over those seas, as fountains of glowing gas arc from the solar disk contrasted against the blackness of space. On closer examination, the solar limb appears rough, a bit like a fine-toothed saw blade, as innumerable spicules, jets of glowing gas, are seen in contrast. Yes, sunspots are visible but are no longer the primary interest.

After many tries and failures at processing images to best show the chromosphere complete with prominences, I finally learned what some other imagers were using to process their images: Solar Toolbox — a package of programming scripts used with the PixInsight imaging application. I still have much to learn about Toolbox but it has already been enormously helpful to me in the challenging world of solar imaging! Thus, the image above is from very good data recorded about seven months ago, now reprocessed using Toolbox.

#2025 #astronomy #astrophotography #solar #solarAstronomy #sun

A fine day for some solar astronomy and a fond farewell to AR4079

Our temporary observing setups are assembled on the base/floor of the planned observatory. The light orange bucket, at center, protects an empty electrical conduit that will provide utility power to a permanent pier that will be installed there. In the foreground is a table supporting a light shield for the laptop computer. The large tripod next to the table supports the white light imaging scope. In the background is the Sky-Watcher SolarQuest mount with our Coronado hydrogen-alpha solar scope attached.

We’re still doing open-air astronomy though we have a nice, solid, clean, and level space to set up our gear! This is the setup we were using today to record the sunspot at active region 4079 as it is about to roll over the solar limb/horizon. Fortunately, though it’s a very temporary setup, the portable gear we use for casual solar imaging is fairly easy to set up.

From an unusual vantage point, a picture of the solar setup used today to record the passage of active region 4079 toward Sun’s horizon. The red object is the planetary camera.

We continued experiments to determine what gear will work together for imaging. There were a few surprises and there’s need for more experimentation. What we settled on for today’s solar efforts is pictured above and includes: Askar 103 APO telescope, Meade LXD75 Goto Mount, TeleVue 2X Barlow, Baader Planetarium Safety Herschel Wedge, and ZWO ASI678MM monochrome planetary camera.

The sun as it appeared at 11:32 AM EDT on May 10, 2025. Sunspot/Active Region numbers are labeled in this image with AR4079 very near the solar western limb or edge.

Although the sky was clear, seeing was a bit shaky so once again, sharpness wasn’t what we’d like. Still, in all, we got the shot we wanted and learned a few things about our astronomy equipment. Also, the sky was blue, the air was pleasant, and birds were singing, so not a bad way to spend a couple of hours.

A closeup view of the sunspot at AR4079. There is a bright line splitting the dark central umbra of the sunspot, the gray penumbra radiating in filaments around it. White cloud-like areas surround the sunspot, especially to its north; called plage, they are associated with areas of concentrated magnetic field.

#2025 #AR4079 #astronomy #astrophotography #observatory #solar #solarastronomy #sun #sunspots #telescopes

An April SolarQuest — Photobomb Included

The Sun, as it appeared on April 17, 2025, in hydrogen-alpha light. The image was recorded using a Coronado solar telescope, a Sky-Watcher SolarQuest mount, and a ZWO ASI 678MM camera. Photo by James Guilford.

Taking advantage of midday clear skies, Thursday, we set up the hydrogen-alpha telescope and did a little observing and imaging. Seeing conditions were only good but we could make out several prominences along Sun’s limb. (The proms did not record well and we need to figure out how to enhance their visibility in our images.) Most notable, however, was the shear number of filaments in Sun’s northern hemisphere. None visible in the south! Fragments of exploding filaments launched from Sun and produced two CMEs that, when they reached Earth on April 16, caused strong geomagnetic storm activity and widespread auroras. The storm, however, died out before northern lights could be seen here.

The Sky-Watcher SolarQuest mount is shown here aiming our Coronado 60mm hydrogen-alpha solar telescope at Sun.

Aiding in our efforts was a device we used for the very first time in this session: The Sky-Watcher SolarQuest with its HelioFind system. The device is lightweight, easily supported our rather robust Coronado solar telescope, and was exceptionally easy to learn and operate. Essentially, all that was needed was to set the tripod up so that it was level, turn the device on, and let it do its thing! It is powered by four AA batteries, placed inside the unit. As an alt-az mount, no counterweights or muliti-axis balancing was needed; just mount the scope with its balance point at the center of the dovetail clamp. No remote control, no app, the compact and self-contained SolarQuest established GPS contact, leveled the scope, then looked for Sun. The SolarQuest turned and elevated the telescope, quickly acquiring our nearest star. When the motion stopped, we looked through the eyepiece to discover Sun well within the field of view. A few nudges of the system’s adjustment buttons and Sun was centered. Tracking was excellent throughout the observing/imaging session. Provision is made for further refinement of tracking but that adjustment was unnecessary for the day’s activity. The SolarQuest will make our daytime astronomy a whole lot more convenient and enjoyable!

A business-class jet airplane trailing twin contrails is seen in silhouette against the roiling surface of the sun. The image is recorded in hydrogen-alpha light. Photo by James Guilford.

We had just finished setting up for some solar astronomy and tapped the button to begin a video sequence when something flashed across the computer screen. A jet appeared for less than a second, contrails briefly persisting, silhouetted against the roiling solar disk! We’ve only seen this twice while observing Sun, this being the second time, and we only captured this image by shear luck. The first time we witnessed a solar “photo-bombing” was under similar circumstances. Previously, we had completed setup, was refining focus, and just about to begin recording exposures. We missed imaging that encounter by about the same interval as we succeeded this time!

#2025 #astronomy #astrophotography #Coronado #photobomb #SkyWatcher #solar #solarastronomy #solarobserving #SolarQuest

Reflection grating seen through collimation lens. This grating was once part of the swedish vacuum solar telescope. #physics #solarastronomy #spectroscopy #astronomy
Tried the Seestar S30 “scenery mode” from on top of the Berkeley Hills just now. Not a bad image of @SutroTower and SF despite the bad seeing at this angle. Then a shot of today’s sun, that sunspot on the left hand side of the image might be related to the large flare that went off yesterday (not facing Earth). #sf #sanfrancisco #sun #solarastronomy #spaceweather