Montes Apenninus

The Apennes Mountains on the Moon
Montes Apennius bisects Mare Imbrium and Serenitatus

As a child, my family would visit the Great Smoky Mountains in Tennessee, often multiple times a year. I imagine future lunar citizens might vacation in the Apenninus mountains, a beautiful chain of mountains that curves along the edge of Mare Imbrium on the left side of this image. Named after a mountain range in Italy, it has a small gap (perhaps analogous to the Cumberland gap of my childhood home) that opens the way from Imbrium to the sea of Serenity to the right. Were the lunar maria actual oceans, there would for sure be a vibrant trading city located here as the most practical passage between these two great seas.

Alas, this is the Moon, and the Maria are indeed not waterways, but vast plains of cooled lava… well… a sea of frozen lava is still a sea, isn’t it?

Taken on the night of May 16, 2024, the lighting here is really quite outstanding for great views of a number of prominent features in this area of the Moon. At the upper left we see the crater Plato, which often looks quite shallow and flat. Due to the Sun’s angle at this time however you can see the highly detailed walls of the crater rising high above the smooth surface of Mare Imbrium. To the upper left of Plato, you can see a small ring of light that is the crater Fontenelle. Through the eyepiece this night, that ring was glowing in the darkness of the terminator like the lights of a great city in the night.

Midway down and to the left of the Apenninus mountains is another flat and smooth crater Aristarchus. Like Plato this crater appears to be older than the Mare Imbrium as its floor is flooded with the same cooled lava that surrounds it. A younger crater at the southern tip of the mountain range is Eratosthenes. There is no smooth floor here, and in the center, you can see a tiny dot of light that is the central peak of a mountain of material that was rebounded when the impact crater was formed.

While the Moon is not quite as dynamic as the Sun, it is different every night, and even every hour you can see changes in the surface as the light and shadows dance across the lunar day. Even the smallest telescope or binoculars will reveal this world to you, and I encourage you to go take a look as often as you can.

Just One Hour

The August, 2024 issue of Sky & Telescope has an article by me about shooting star trail images. It’s too bad I didn’t have this shot before because it’s my favorite star trails image to date. I setup my camera behind an equatorial mount (I was shooting M106 at the time), and set my canon EOS Ra to take 30 second exposures repeatedly. Then, as I describe in my afore mentioned article, I loaded all the images as layers in Photoshop and set the blend mode to “Lighten”. I did paint out a few airplane trails in the individual layers, but otherwise the image is accurate. There are even a few short meteor bursts if you look carefully for them.

Star trails over a telescope
One hours worth of star trails show just how much the stars appear to move in such a short amount of time.

This image shows why we use an equatorial mount for long exposure astrophotography. As the Earth spins, the stars move considerably, and in this case you can see exactly how much in only an hours time. An equatorial mount works by aligning it’s axis of rotation with the Earth’s, and then rotating in the opposite direction of the Earth’s motion. It’s like being on a merry-go-round, and you have to turn your head to keep looking at someone or something off in the distance. Without an equatorial mount, objects zip by in the eyepiece or camera pretty quickly. There are also alt-az mounts that track objects in the sky without having to do much alignment work, however, because of the way they move, objects in the camera will rotate in place as you track them across the sky. This makes long exposures a bit more challenging 😉

For context, I’ve added just a single 30 second frame as well. As a stand alone image, it’s not too bad either IMHO.


A telescope against a starry sky
Here’s just one of the 120 frames used to create the star trails image.

Totality at Last!

Total Eclipse SequenceYou’d think given my years of astrophotography (if not just my age!) that by now I’d have seen a total eclipse. The total eclipse of April 2024 that crossed North America was not my first attempt at a total eclipse, but it was my first successful attempt at witnessing a total eclipse! I can now tell you; the hype is real.

The Diamond Ring Effect
The Diamond Ring at the beginning of totality during the 2024 total solar eclipse.

I went to the Texas Star Party, which was moved both in location and time to coincide with totality and we were nearly right on the center line for nearly four and a half minutes of totality. That was the fastest four and a half minutes of my life. I can now understand why people tell you that you should not “focus” on astrophotography at your first totality. Of course, that advice is lost on me (and probably some of you) because photography is in our DNA. I did not however completely ignore the advice. My photography rig was 99% automated. All I had to do was remove the front white light filter at totality and put it back on after totality.

My gear choice was pretty much ideal. I used an equatorial mount to keep the Sun’s orientation constant throughout the eclipse (Sky-Watcher Az-EQ6 in EQ mode). I polar aligned it on a previous evening using the integrated polar scope. For optics, I used an Astrophysics Stowaway 92mm refractor with the f/7 flattener. I had made a front mounted white light solar filter from Baader solar film for the 2017 eclipse that I reused this year. I

Total Eclipse
The Sun and Moon during totality. Note that bright prominence at the bottom just peeking through low areas on the lunar limb.

removed it during totality, and thus got nice safe images of the partial phases, and when it was safe (for the camera) I got Baileys Beads, the Diamond Ring, and some great prominence and corona images during totality. The camera was a Canon EOS Ra mirrorless full frame camera. The “a” means astronomical as it is slightly more sensitive to the hydrogen alpha wavelengths of emission nebula… and as it turns out, solar prominences!

Finally, the software the drove the sequence on my MacBook Pro was “Capture Eclipse”, which is a great program I can’t recommend enough. I rehearsed at home of course, and I focused using the @focus3 algorithm in TheSkyX Professional (which I wrote btw) on the sunspots right before the eclipse started. The telescope was already at equilibrium, so there was no focus drift during the eclipse.

Prominences on East side
Prominence’s on the Eastern limb of the Sun. Note the rather large triangular prominence at the bottom. This was visible to the naked eye during the eclipse.

I must say, I really lucked out. Sure being prepared helps, trying repeatedly helps, but the weather forecast shifted from seasonal norms to mostly cloudy for eclipse day. We got fortunate that the clouds parted for us and although we had a few thin clouds and the occasional thick cloud, we were rewarded with a glorious view of totality. While I’m very pleased with my images, there is absolutely no comparison to the view naked eye. If you can possibly make it to center line for a total eclipse, I highly recommend you make the effort. I know my passport will be ready for some future eclipses…

Additional and larger versions of these photos are available in the Sun gallery. My favorite shot of Baileys Beads is below!


Baileys Beads just before totality ends. These are caused by sunlight filtering through gaps in the lunar terrain like mountains, valleys, and craters.

A Tale of Two Filters

Like a lot of photographers in North America, I’ve been making preparations for the total eclipse coming up in slightly over a month now from the time of this writing. I’m planning to take an arsenal of solar gear and spend a couple of days doing solar imaging with a variety of gear and techniques, and fleshing out some software I’m working on for lucky imaging to boot. This means I’ve been doing a lot of solar viewing and imaging in my back yard, and cycling through gear to make sure I have all the right adapters, spacing, etc. There was a very active region on the Sun (AR 3590) on the clear afternoon of February 27th and I had a chance to image it in white light and then just a few minutes later in Hydrogen Alpha. The difference is quite stark and I thought very illustrative.

Two images of AR 3590
Active Region 3590 in Ha and white light.

The telescope was a Sky-Watcher Esprit 150 (still my favorite optic for just about anything), which I had on my Paramount MX+. The Paramount’s have the smoothest motion of any mount I’ve ever used for any kind of high resolution Solar or Lunar work, but back to topic. The top panel at right was taken with a 4x Powermate to get the image scale and focal ratio higher for the Daystar Quantum hydrogen alpha filter. I used a Player One ERF (Energy Rejection Filter) in front of the PowerMate. I don’t use a big ERF in front of the 6″ objective, but 6″ is about as large a refractor as anyone should dare use for solar without a larger ERF in front of the aperture. The camera on the back was Player One Apollo Max, and I shot about 5,000 frames, of which I used 20% for the final stack. The original image was monochrome, but I colorized it as most people (my wife especially) prefer to see a nice color image. The mad truth is the single wavelength of Ha is an electric pink, but the convention is to make these images yellow to conform with the public’s perception of what color the Sun should be.

Ha images are stunning. They show in stark relief how the gasses are flowing along magnetic field lines on the Sun’s surface. The darker areas are still quite hot and blindingly bright, but they are just ever so cooler than the surrounding areas, and the white areas are as you’d expect super hot and bright.

The bottom image was taken with a Starfield Herschel Wedge. A Herschel Wedge is a lot like a normal star diagonal you see on many telescopes, but it let’s the majority of the Sun’s light pass through it out the back. A tiny portion is reflected up towards an eyepiece or camera for viewing. It simply dims the Sun, so you see the Sun as it actually appears, just a lot less bright and hot. Not using a filter like this would blind you instantly, or melt your poor camera before you could hope to get a shot off.

I still used a 4x PowerMate and the monochrome Player One camera, but replaced the Player One ERF (which is tuned for Ha imaging) with a standard UV/IR filter. The Herschel Wedge does not need this normally for visual work, but when doing photography, it eliminates some of the stray light that would be out of focus. The result is a “White Light” image of the same region. You can still see some of the same overall structure of the region, but you are not seeing the effects of the magnetic field lines that are more pronounced in the hydrogen bandpass.

The true color of the bottom image is actually… white. The Sun appears white in space, and even on Earth when directly overhead. It’s hard to tell of course because well, looking at it long enough to study it’s color would of course blind you! Still, I chose to colorize it for aesthetic purposes to match the image above. Scientifically, the images represent the structures accurately (even the limb darkening at upper left is real), but the colors are for taste alone.

I hope you can forgive my creative license (or shameless conformity), and enjoy seeing the difference between these two common ways to filter and view or photograph the Sun.

Bernard’s Merope Nebula

Merope Nebula image
Bernard’s Merope Nebula

This was a challenge target for me. Last month I was writing my monthly astrophotography target of the month column for Sky Safari (you will need a subscription to see it in Sky Safari Pro), I realized I did not actually have a good image of the Pleiades that featured this tiny jewel (cataloged as IC 349). I love to shoot the larger reflection nebula with a newtonian reflector because it makes beautiful diffraction spikes, but the spikes would obliterate this tiny little interloper to M45. Same with other refractors (or my Officina Stellare RH-200) I had used with longer exposures – the star Merope would swell up and swallow this nearby nebula, which physically is only 0.06 light years from the star!!

The Pleiades are a relatively bright group of stars and nebulosity, so I went for a short run under somewhat light polluted skies. I used 111 good 30 second exposures stacked for this image, and stretched VERY gently with the histogram and curves tools. The seeing was not super great that night with my Espirt 150 refractor and a Player One Ares-C Pro cooled color camera, so I confess as well I used the very nice Blur Exterminator to tighten the stars a little bit.

An interesting personal experience about this image. This is the first time since I’ve started wearing glasses (none of us are getting younger!), and just like a star test is a good way to test optical flatness, I found that when judging my star field on the computer screen, I could see… and DISTRACTINGLY SO… distortions in the star field that aren’t actually there. This can make it very hard to judge an astro image, and I now have TWO pairs of glasses. One for “most of the time”, and one for when I’m using my computer or working… um… well, truthfully that IS most of the time – LOL.

P.S. Happy New Year and Clear Skies!

Purple Haze

The great annular eclipse of 2023 has come and gone. The internet and social media are flooded with amazing shots of the Sun. Most are red or orange, and there are a few white light images taken with white light filters or solar wedges. “The Ring of Fire” was not in the cards for me this year, and I had to be content to observe and image the event from my driveway in Central Florida. I shared the event with neighbors and gave away some solar glasses from DayStar filters. No eyepieces though, I had a camera on the back of the telescope (oh, did this require some “explaining” and warnings), and a black and white image of the Sun was displayed on my laptop, cleverly shielded from the hot bright sun by a cardboard moving box.

Solar Eclipse in Calcium Light
Maximum Eclipse from Central Florida in Calcium-H light

My processed images though are Purple. Whaaat?!

I used a Daystar Calcium Quark, specifically the Calcium-H line. Some of you know this, but many people do not know that much of what we know about the Universe and what things that are far away are made of, is done by studying the light we receive from them. Here’s a great article on the Hubble Space Telescope web site that explains some of how this works: What is Spectroscopy.

So, back to the Wright Earth Telescope(s). The filter I used on the eclipse is what we call a “narrowband” or “Line” filter. It only let’s through a very specific wavelength of light, and this filter is tuned for the H line of Calcium (396.9nm), which if you had looked at it through an eyepiece, would have been a deep purple! I once had a similar dedicated telescope that was for the Calcium-K band, which also appears Purple, but is so deep that many people cannot actually see the details on the Sun’s surface. I’ve heard various explanations about genetics, and “old people”. My own experience is that I could see it years ago, and now when I first look all I see is a smooth purple disk. Then as I fish around, my eye will suddenly focus and I can see it for a few seconds, and then it’s lost. I don’t think it’s so much “detecting” the wavelength (which is very far towards the violet), as your eye loses the ability to focus on it. Maybe that’s the same thing. We’ll see if in another few years if I can ever catch the surface details any longer.

But this is why the Calcium-H line is very popular for visual solar observing. It reveals a very similarly detailed image and can be more easily seen visually in an eyepiece. Since it’s monochromatic light (just a single wavelength), typically what imagers do is use a more sensitive monochrome camera, and then colorize the image after they are done processing the image for sharpness and contrast.

The Gear

Telescope pointed at the Sun
Driveway Solar Astronomy. Be sure and share with your neighbors

I used a Sky-Watcher AZ-EQ6 mount in Alt-AZ mode. That was more mount than needed for my tiny Takahashi FS60-CB telescope. It has a fluorite lens, and many people worry about damaging fluorite with solar observing. It is true, fluorite lenses can be damaged by sudden temperature shifts, but here’s the thing about glass lenses… light passes through them. They don’t really absorb much heat. If your optic however gets too far off the Sun, and the concentrated light starts hitting your baffles or the edge of the tube, you can superheat the inside of the OTA, and bad things can happen. Bad things. I do understand some older oil space lenses can be problematic for solar though, so check with your manufacturer before you start tinkering with hot sunlight.

Inside the tube, I had an IR/UV filter, which reflects a great deal of the Sun’s invisible, but heat bearing wavelengths right back out the front of the telescope. Behind that was an Astrophysics 2X barlow. I love this barlow because it also acts as a flattener. If you are doing full disk solar work, or even high resolution solar or lunar work, it annoys me terribly when I use a large sensor and only the middle of the image is really in focus. The solar filter was the Daystar Calcium-H Quark and the camera was Player One Ares-M (IMX 533 monochrome) that I ran cooled to zero degrees C. This was a lot of fun to explain to the neighbors. Concentrated sunlight is going through a filter heated to a specific temperature, that then reaches a camera that is cooled and kept at 0 degrees Celsius. I’m just your average mad scientist working in his driveway…

Clear skies, day or night friends!

A Celestial Dolphin

Here’s a “cool” looking image for all the hot summer days we are having right now! A really amazing object in the southern sky in the constellation Canis Major (the Big Dog), is a big gas bubble cataloged as Sharpless 308. It has a popular (but unofficial) name of the Dolphin Nebula. It’s in the Sharpless catalog because of it’s Hydrogen Beta emissions, but it is especially bright in ionized Oxygen III. This image is about two hours of exposure time through a 3nm Chroma OIII narrowband filter. It’s amazing that we can photographically identify elements this way, but the OIII atoms emit a very specific wavelength of light, and this filter let’s only that wavelength through (well, plus or minus 1.5 nanometers!).

The Dolphin Nebula
Sharpless 308, or the Dolphin Head Nebula

The central star is pre-supernova and is responsible for blowing off all this gas, and is about 4,530 light years from Earth.

Artistically, this was a tough image for me. I took it back in February of 2023 at the Winter Star Party and only now (late July) am I satisfied to publish it. I did take about 1/2 hour of RGB data to give the stars color, but this is basically just an Oxygen emission image of this target. I went back and forth on the coloring. OIII is Cyan (blue/green), but of course the light is far too dim to see. What color is something that’s invisible? I settled on this, and finally even decided I liked the smoky background oxygen that is glowing around/behind the main focus of the image.

Gear used:
Sky-Watcher Esprit 150 refractor
Night Crawler Focuser
Player One Poseidon-M Camera w/Phoenix Filter Wheel
Chroma 3nm OIII narrowband filter
Software Bisque Paramount MYT
30 minutes RGB exposure time
2 Hours OIII exposure time

You can now find me on SkySafari Pro!

Featured Story image of M13
SkySafari "Tonight"
Click “Tonight” from the toolbar to see featured items.

I’m three months late with this post, but I’ve started writing a monthly feature/blog for SkySafari that is available to their premium subscribers! Each month, I’ll be calling out an astrophotography target for that month and talking a little bit about the object itself and some general tips for astrophotographers. SkySafari is available for both iOS and Android and is one of the most popular (if not the most popular) mobile astronomy apps. You can use it to find or identify objects in the sky, get notifications about astronomical events, and configure your telescope/eyepieces/cameras to plan viewing or imaging sessions. It also controls a great number of telescopes and has a huge database of objects you can search.

This month I’m talking about my favorite target visually, which also makes a pretty nice astrophotography target, M13 (Messier 13), or the great globular cluster in Hercules. Past articles are also available. Last month was the large galaxy M101, and before that the Leo Triplet of Galaxies. It is “Galaxy Season” after all. Each month, I’ll focus on a target that is ready to go at evening astronomical twilight (when it’s dark enough to image deep sky targets). It’s going to be a very long time before I run out of targets to talk about, and I hope you will check it out and enjoy!

If you have SkySafari 7 Pro and already have a subscription to the premium features, just click “Tonight” on the bottom toolbar on your mobile phone or tablet.



Winter Star Party 2023

WSP Welcome Image

The annual Winter Star Party in the Florida Keys is my favorite annual event, always held in February or occasionally in very late January or early March. It’s almost a religious pilgrimage for me, and I’ve only missed once in 20 years since I started attending, and that was due to a death in the family (I was already packed and loaded when I got the worst phone call of my life… but that’s another story).

Morning Milky Way
Earth clouds on star clouds. The Summer Milky Way makes an appearance just before dawn.

What’s so special about the Winter Star Party, or WSP? I think it’s the location and of course the people. A star party is after all a social event, and I have met many lifelong friends at WSP. It’s currently held at adjacent girl scout and boy scout campgrounds on “Scout Key”, south of Marathon, but sill 40 miles from Key West. The girl scout side has been ravaged by hurricanes and is a bit more of a primitive camping experience. The boy scout side however is well manicured, has power, a clean and modern bath/shower facility, and even “glamping” tents with AC. Yes, both sides have been hit by the same hurricanes, but the boy scouts have built back. It’s never too late to teach our children that the boys have all the money and get the nicer things… (that’s sarcasm btw… or an indictment, take your pick).

Omega Centauri Image
Hands down, my favorite WSP image visually or photographically is the great globular cluster Omega Centauri.

There is light pollution from the keys of course, so it’s not “Okey-Tex” dark skies, but the view to the South is dark, and only with a long exposure (with a camera on a tripod) can you see a small light dome on the horizon… from Havana Cuba! The southern sky is a treat, among my favorites, there’s Omega Centauri, the king of globular clusters, Centaurus A, an amazing irregular galaxy, and if the weather gods show favor — the great Eta Carina nebula will make an appearance, no more than 6 degrees above the ocean’s most southerly view.

Centaurus A Image
Centaurus A is a peculiar galaxy and one of my favorite WSP targets.

The keys are a special place too. I live in Florida, but I live near Orlando and the “attractions” are only an hour away. The Florida Keys are almost like another state entirely. Tropical beaches, the vibrant blues and green of the ocean, tiki huts, and seafood galore. People from all over the world come to my part of Florida on vacation. If you live here, going to the Keys is where we go on vacation. There’s plenty to do in the keys too for your non-astro-nut family members. Key West is also a whole other world in itself. You can rent a boat, go snorkeling, kayaking, fishing, the list is endless.

Epic Dew
Soaking wet dew graced us the last clear night of the star party.

This past year was my first year in nearly two decades that I did not attend as a vendor representative, and the first held in three years due to cancelations over the Pandemic. The weather was clear, but windy most of the week, and the smart astrophotographers found places in the lee of the wind. I managed to get some good deep sky data, and even did some lunar and solar lucky imaging.

The last clear night was Friday, and the air was still, and heavy with dew, the worst dew event I recall at this event. I had not prepared for this, and my scope dewed over immediately after dark. I put on a dew strap, cranked it up, and used an alcohol wipe to repeatedly remove the moisture. It took about 45 minutes, but finally I was back in business and got my best image data of the week that night. In fact, I hit the celestial jackpot that night.

Eta Carina Image
Not too bad for only 40 minutes worth of time between 4 and 6 degrees above the horizon!

Early in the morning a friend behind me was “observing” Eta Carina, only about 4 degrees above the horizon. I thought, “well, why not”, and I tried a slew and a single exposure. I expected it to be behind a tree, or below the berm between me and the beach. Surprise! It was not well centered, but it was there, and it was bright! I carefully centered it and found tracking was not that great so close to the horizon, but I could take decent enough 15 second exposures. So, I took 156 of them before a tree did in fact obscure my view! I alternated between red, green, and blue with my monochrome Player One Poseidon-M camera and managed to pull off a decent enough image. One day… I MUST travel south of the Equator to do this target justice.

In the meantime, I’m counting down the weeks until my next “Latitude Adjustment” in February of 2024. See you there? Stop by and say hello!

First Light with a Player One Poseidon-M

Image of Player One camera
Image of Player One camera
I think we are going to make beautiful music together….

I plan to do a longer and more thorough report on the Player One Poseidon-M camera at a later date, I’ve only just received it recently and have had a spotty few nights out with it, but I’m pretty impressed so far. I ordered a full set of Chroma filters for it, and my first clear night the only filter that had arrived was a 3nm Ha (Hydrogen Alpha) narrowband filter. The Moon was up and well, Ha is great in the moonlight, and I could not wait to try the new toy out.

Well, who doesn’t shoot M42 when they get a new camera? It’s bright, it’s pretty, and it’s loaded with glowing hydrogen gas — I have a shiny new camera and high quality 3nm hydrogen filter. I wanted to see how much detail I could get out of the trapezium, which is the very bright core of M42, so I experimented to see how long I could go without saturating that region. I was shooting at high conversion gain (HCG), but could go a full minute and still make out the four stars of the trapezium. The screen stretch showed glorious detail already and so I decided one minute was enough.

Hydrogen Alpha image of M42 region
Who doesn’t shoot M42 when they get a new camera?

Orion passes between two trees from my backyard each night, and I only got 104 of these one minute exposures over two nights, but it was quite enough for an impressive image non-the-less of the entire region. I would have liked to get more to reduce the noise in the outer areas, but it is definitely good enough for the internet as is. One minute narrowband subs (oh, this was at f/7 by the way) is pretty impressive, but I have to admit, M42 is a pretty bright target, so I tried a few others also at shorter exposures.

Tadpoles in Ha
Tadpoles are a must image with narrowband filters.

I did some one and two minute exposures on the Rosette and the Tadpoles and stacked equivalent spans of time for each. The one minute stacks did not suffer from what I could tell from a qualitative inspection vs. the stack of two minute subs (both stacks of about half an hour).

I also did 162 x 60 seconds on the Cone nebula region. The screen stretch of the individual subs was very faint on this region, but the stacked result was quite spectacular I thought. The fox fur region is just loaded with detail and subjectively I’d say it’s every bit as good as what I used to do with CCD’s and longer (individual exposures).

Rosetta nebula in Ha
A very popular target in Ha, the Rosetta nebula does not disappoint.

I’ve been speaking about the new age of shorter exposures for a while now, but I’ll abbreviate my thesis in that shorter individual exposures are becoming more usable due to camera improvements, but the total integration time for a quality image has only diminished very slightly due to increases in QE (Quantum Efficiency). There is still only so much light coming from astronomical objects, and it still takes hours of total integration time to create a very high quality image. These images look great on the web, but if I were to print them or display higher resolution versions, I’d want a little more integration time to better smoothen them out (from shot noise).

I plan to push on this camera pretty hard, do a lot more experiments (both qualitative and quantitative), write some software, and take some pretty pictures. Stay tuned…

Cone nebula region
One minute Ha subs at f/7. Individual subs were pretty faint, but 162 of them turned out quite nice!

Oh, and if you can, be sure and catch my talk on “The Future of Astrophotography” at the upcoming Winter Star Party, or you can read a reprint of my August 2022 Sky & Telescope article “The Next Big Thing” here.