Figure 1 – The Bortle Scale Credit: ESO/P. Horálek, M. Wallner

Many things seem better in our remembrance of them. I used to observe with my 60 mm Unitron Refractor in NYC, doing everything wrong (like looking through my apartment window with my telescope). But, and in any event, I was always limited by the light pollution presented by the big city. But in summer I would go to “Upstate NY” and “wow” the skies were spectacular and the beauty of the Milky Way could bring one to tears. I’m a romantic.

Today we struggle in most places to catch a glimpse of the Milky Way. Indeed, in most places you stand no chance of seeing it. Light pollution is the bugaboo of amateur astronomy.

The Bortle Light Pollution Scale is a nine-level system used to measure the quality of the night sky based on light pollution. It was developed by John E. Bortle in 2001. This scale helps both casual observers and serious astronomers assess the level of light pollution in a particular location. It was designed to aid in comparing different locations and providing a better understanding of how much artificial light interferes with stargazing. You can chose a site based on it and putting the Bortle Number in your observing notes makes you feel really in the know, even though you have no control over it.

The scale is inverse, meaning the lower the number the better, Bortle 1 (Excellent Dark-Sky Site) to Bortle 9 (Inner-City Sky), with each class offering a description of what can be observed and the degree of light pollution in the area. It is akin to the magnitude scale, where smaller means brighter.

Breakdown of the Bortle Scale

Bortle 1 – Excellent Dark-Sky Site

• This is the ideal environment for stargazing. Observers in this location will experience pristine, unpolluted skies with no significant artificial light. The Milky Way is visible in all its glory, and faint objects like galaxies and nebulae are easily observed with the naked eye. This is typically found in remote locations, far away from urban centers, where artificial lighting does not reach. I’ve read about shadows cast by the Milky Way in Sagittarius and Scorpius. I mean really? That’s just amazing!

Bortle 2 – Typical Rural Sky

• Rural areas with very little light pollution fall under this class. The Milky Way is clearly visible, though some light pollution may slightly affect the sky. While bright stars are easy to spot, the faintest deep-sky objects might be harder to detect without a telescope. Still, it’s a good location for casual stargazing.

Bortle 3 – Rural/Suburban Transition

• This is a more common location for many stargazers, found in the outskirts of rural and suburban areas. The Milky Way is still visible, but there is some light pollution that washes out fainter stars. The sky is noticeably brighter, and some constellations may be less prominent. It is a compromise between access to nature and light pollution.

Bortle 4 – Suburban Sky

• Observers in suburban areas will find a considerable amount of light pollution, but brighter celestial objects like planets and the Moon are still easily visible. The Milky Way is generally not visible, and the sky is noticeably bright. Faint deep-sky objects will likely require binoculars or a telescope to be observed clearly.

Bortle 5 – Bright Suburban Sky

• This class represents urban areas that experience significant light pollution. While brighter stars and planets are still visible, the sky is heavily washed out, and the Milky Way is completely obscured. Faint deep-sky objects are impossible to see without a telescope, and the environment is illuminated by the glow of nearby city lights.

Bortle 6 – Light-Polluted Sky

• Locations in Class 6 are typically in the periphery of urban centers where artificial lighting dominates. Only the brightest stars and planets are visible, and the sky is a dull, murky gray. The Milky Way is completely invisible, and very little astronomical detail can be seen with the naked eye.

Bortle 7 – Moderately Light-Polluted Sky

• As you move into more urban environments, the light pollution intensifies. The sky is overwhelmingly bright, and only the brightest stars are visible. The light from nearby cities creates a strong glow that makes it nearly impossible to observe faint stars or deep-sky objects. This class is common in larger cities.

Bortle 8 – Very Light-Polluted Sky

• In cities with extreme light pollution, only the most prominent stars can be seen, and the sky is typically washed out with artificial lighting. The night sky may appear orange or yellowish due to street lights and city lights. Even with a telescope, the ability to observe deep-sky objects is severely limited.

Bortle 9 – Extremely Light-Polluted Sky

• Class 9 represents the worst light pollution, typically found in the heart of large metropolitan areas. The sky is completely dominated by artificial lights, and very few stars can be seen with the naked eye. The Milky Way is entirely obscured, and observing celestial objects is nearly impossible without extremely specialized equipment

Figure 1 is an excellent resource from the European Southern Observatory that shows how the Milky Wat fares against light pollution at each Bortle Number. When I observe in Sudbury I am at a Bortle 5.7 and have no chance of making out the Milky Way and many deep-sky objects are bleached out. But nevertheless this is pretty good and I am grateful to have those skies. In Rockport were I often go in summer I am at Bortle 4.2 and the Milky Way seems to blink on and off. You see here the obvious advantage of the Observacar over a fixed site. Don’t like your Bortle Number and you just have to hop in your Observacar and drive somewhere else.

I have heard that AI based telescopes like the ZWO Seestar 50s and the Celestron Origin can figure out what they are pointing at, the so-called “solving of the plate,” in Bortle 8 skies. Take another look at Figure 1 again. You wonder how this is even possible. Add a near full moon and things get really dicey.

Amateur astronomers are ever in the search of or, covetous of, clear skies. Light pollution is one of those things that deprive us a fundamental element of what it means to be human. To see a sky unpoisoned by artificial light is to connect with the humans that first inhabited our planet. I wish you Clear Skies everyone!

Figure 1 – NGC 1398 iTelescope T73 (c) DE Wolf 2024

It is spring, friends! The time change has passed and the sunsets later and they lead to warmer nights. I am at present trying to get trying to get my big eight inch Nexstar up and properly running so that I can finally do some planet observing.

Also, I have been venturing out to the wildlife refuges again. And I hope to have some good bird photographs for you again. This weekend I am going to Plum Island in search of white owls and piping plovers. Wish me luck

Figure 1 today is of the dramatic NGC 1398 galaxy and was taken using itelescope T73 in  Rio Hurtado, Chile just at the start of the New Year. As a reminder this is a 0.50-m f/6.8 reflector with a 26.93′ x 21.53’arc-mins FOV. 3 images with each RGB filtration of 120 sec each. I am really pleased with how the image came out. I see this and then remember that in my youth my telescope was a 60 mm Unitron Refractor! Times change.

NGC 1398 is a spectacular even majestic galaxy, standing out for its impressive structure and vibrant features. Located in the constellation Fornax, NGC 1398 it is what is referred to as a barred spiral galaxy. A barred galaxy is a type of spiral galaxy characterized by a distinct, elongated central bar-shaped structure made of stars. This bar runs through the galaxy’s nucleus and extends outward, from which the spiral arms of the galaxy typically emerge. The presence of this central bar distinguishes barred spiral galaxies from unbarred spiral galaxies, where the spiral arms directly emerge from the central bulge without a bar-like feature.

NGC1398 was first discovered by the famous astronomer William Herschel in 1835, and it is situated approximately 65 million light-years away from Earth. This stunning galaxy is part of the Fornax Cluster, a rich collection of galaxies that offers a wealth of astronomical discoveries. NGC 1398 is notable not only for its size and composition but also for the intricate spiral arms that define its shape.

In addition to the spiral arms, the galaxy is also surrounded by a faint, extended halo of stars that is common among many galaxies. This halo is made up of older stars and provides valuable insights into the galaxy’s formation history.

The central bulge of NGC 1398 is another fascinating aspect of its structure. This bulge is thought to contain a supermassive black hole, a feature that is often found in the centers of large galaxies. This black hole likely plays a key role in the galaxy’s dynamics and may even influence the formation of the spiral arms.

It is, I think, a curious point that when it comes to astrophotography for the sake of astrophotography, as oppose to astrophotography for scientific purposes, I haven’t graduated to that yet, we are drawn to certain objects because of artistic features. NGC 1398 with the delicate structure of its spiral arms in such an appealing object.

Messier 81 (lower right) & 82 (M82) Celestron Origin image 60 min 360 exposure (c) DE Wolf 2024

Messier 81 (M81) and Messier 82 (M82) are located in the northern sky in the Big Bear or Ursa Major. They are named the “Bode’s Galaxy” and the “Cigar Galaxy,” respectively, They were cataloged by French astronomer Charles Messier in 1774 as part of his mission to identify and catalog celestial objects that could be mistaken for comets. Messier 81 is a spiral galaxy, while Messier 82 is a peculiar galaxy, often classified as a starburst galaxy due to its unusual structure and intense star formation.

These two galaxies are part of what are referred to as the M81 group, a collection of gravitationally connected and interacting galaxies. This pair dominates the group visually but it also contains several smaller galaxies, such as NGC 3077, NGC 2976, and NGC 2366.

Galaxies generally come in groups. The members of our Milky Way’s group, referred to as the “Local Group,” are extensive and include: the Milky Way itself, the Andromeda galaxy (M31), the Triangulum Galaxy (M33). Additionally, there are so-called dwarf galaxies: Large Magellanic Cloud, (LMC), Small Magellanic Cloud (SMC), Sagittarius Dwarf Elliptical Galaxy, Ursa Minor Dwarf Galaxy, Draco Dwarf Galaxy, Carina Dwarf Galaxy, Leo I and Leo II. Our Local Group also contains a variety of other smaller dwarf galaxies that are gravitationally bound to the larger galaxies. These include: Fornax Dwarf Galaxy, Phoenix Dwarf GalaxyAndromeda II, Andromeda III, and the WLM Galaxy (Wolf-Lundmark-Melotte). The extensive list illustrates the extent of gravitational clustering in the universe and by connection the incredible distances over which gravity extends and shapes the structure of the universe.

Messier 81, or Bode’s Galaxy, is one of the brightest galaxies in the Messier catalog and stands out due to its well-defined spiral structure. It is located approximately 12 million light-years from Earth and is part of the M81 group, which consists of a collection of galaxies in close proximity to one another. With a diameter of around 90,000 light-years, M81 is a relatively large galaxy, comparable in size to our Milky Way.

One of the most striking features of M81 is its spiral arms, which are richly populated with stars, gas, and dust. These arms are the sites of ongoing star formation, and the galaxy is thought to be relatively stable, with a low rate of active starburst activity. The central region of M81 contains a bright, active supermassive black hole that likely plays a role in regulating the galaxy’s dynamics. Its steady state contrasts sharply with the more energetic activity seen in its neighboring galaxy, M82.

Messier 82, known as the Cigar Galaxy due to its elongated, cigar-like shape. M82 is a peculiar galaxy, often classified as a starburst galaxy. This means it is experiencing an exceptionally high rate of star formation, far higher than typical galaxies like our Milky Way. The intense starburst activity in M82 is thought to be a result of interactions with nearby galaxies, particularly Messier 81.

Unlike the relatively calm Messier 81, M82 is a turbulent galaxy, with massive amounts of gas and dust fueling the rapid birth of new stars. The central region of M82 hosts a vigorous outflow of gas and energy, creating a dramatic galactic wind. This outflow is thought to be the result of the starburst activity and may eventually expel a significant portion of the galaxy’s gas, limiting future star formation.

The two galaxies continue to interact and there is some evidence that this gravitational interaction with M81 is responsible for the starburst activity of M82. They are believe to exchange material and may at some point merge with one another.

Never setting in northern skies, they are a favorite of amateur astronomers. The image of Figure 1 is a 360 frame 1 hour exposure taken with my Celestron Origin. I framed it so as to bring both galaxies into the image to suggest their gravitational pairing and interaction.

Figure 1 – The Pac-Man Nebula in Monoceros (NGC 281) Celestron Origin 60 min 360 Frame Image (c) DEWolf 2025.

We have been tried and tested all winter, and at last there is the slightest hint of the coming of spring, No matter how hard I try I find it impossible to secure the mount on the tripod wearing gloves. And it is never a good idea to mix optics and hand balms. Anyway, the calendar says that next weekend is the time change and two weeks from that the equinox. So I retreat to the warmth of the Observacar and fantasize of warmer days. Soon enough, and never satisfied, I will be complaining of the humidity and bugs and once more retreating to the air-conditioned comfort of Observacar!

In my last blog I spoke about the naming choice between Thor’s Helmet and Flying Duck Nebula. I really lean toward the intrinsic nobility of the mythic. Today I want to talk about the Pac-Man Nebula. Now someone was definitely given free range here. The nebula is diminished enough without this last indignity.

Still on Monday night I spent a long while capturing it under, or through, somewhat less than perfect skies. The result is Figure 1. The name Pac-Man gets you thinking of diminutive things and it seems to look more like a celestial backfire than a majestic nebula.

The Pac-Man Nebula—a glowing, colorful cloud of gas and dust located in the constellation of Monoceros. The Pac-Man Nebula (NGC 281) is a H II region, which means it’s a large cloud of gas and dust that is predominantly made up of hydrogen. Note, what looks like a smudge in the center of the image. That is a classic Bode body where absorbant dust blocks the underlying light of the nebula. This nebula lies about 9,500 light-years from Earth and spans roughly 5,000 light-years across. It’s a beautiful region in the Milky Way, where new stars are being born in the dense molecular clouds of gas.

Like many other emission nebulae, the Pac-Man Nebula is lit up by the intense radiation from young, hot stars at its core. These stars emit ultraviolet light that ionizes the surrounding hydrogen gas, causing it to glow with a reddish hue.

In the figure, the cloud of gas takes on a distinct form, with a large, round “mouth” that resembles the iconic character of Pac-Man, about to “eat” its surrounding space.Its resemblance to the classic arcade character isn’t just a coincidence, but rather due to the complex interplay between the intense radiation from the stars in the nebula and the surrounding gas. The stars at the center of the nebula are carving out cavities in the surrounding hydrogen clouds as they push their stellar wind and ultraviolet radiation outward, creating a “bite” on one side of the nebula. Much like we saw Stellar Winds rip apart gas clouds in the Thor’s Helmet Nebula.

The Pac-Man Nebula is not only beautiful, but it’s also a star-forming factory. Within the cloud of gas and dust, young stars are being born. Some of these stars are still in the process of forming, while others have already ignited and are illuminating the surrounding nebula with their energy.

The Pac-Man Nebula contains many massive stars. These stars are so large and hot that they produce powerful winds that clear away the surrounding gas and dust, shaping the nebula. As they age, these stars will eventually explode as supernovae, enriching the surrounding space with heavy elements that will go on to form new generations of stars, planets, and perhaps even life.

The nebula also contains many smaller, less massive stars that are forming in the dense regions of the nebula. These stars will have a much longer life span than their massive counterparts, and they will slowly settle into a more stable phase as they mature over millions of years.

When a supernova occurs, it sends shock waves through the surrounding gas and dust, triggering further star formation. The energy released by these stellar explosions also spreads heavy elements (such as iron and oxygen) into the interstellar medium, enriching the gas clouds and helping to create the building blocks for new stars and planets. In mythological terms these represent the anvils of the gods.

Figure 1 – NGC 2359 the Thor’s Helmet Planetary Nebula (c) DEWolf 2025

This image is right off the presses. The weather here has continued to be snowy, icy, and cloudy. It’s been too treacherous to take out the telescope, Observacar or no! I am hoping that the recent thaw and melt will make it observing safe for this coming Sunday or Monday.

In the meanwhile, I was driven back to my favorite remote telescope, a 20″ beauty on the iTelescope.net in Chile known as T72. I had my eye recently on some wonderful imagrs of NGC 2359 referred to as the Thor’s Helmet or flying Duck Nebula.Thor’s Helmet sounds more mythic and besides lends itself to embeding music from Wagner’s “Ride of the Valkyrie!” So I decided to do some remote telescope imaging. I looked at the absolutely perfect all-sky camera from Chile and was absolutely sold.

First, the particulars about the telescope. PlaneWave Instruments CDK 20″ f/6.8, 3411mmFL, FLI ML16200, Blank,LRGB, SII,Ha,OIII,U,V,B,R,I Filters. PlaneWave Instruments L-500 Mount. Observatory: Deep Sky Chile at Rio Hurtado Valley, Chile – MPC X07. South 30°31’34.712″  West 70°51’11.865″ . Elevation: 1710m  MPC X07 

Figure 1 shows the results of 36 min imaging. I am very happy with it. Exactly what are we looking at here? This intricate and vivid planetary nebula is located approximately 15,000 light-years away in the constellation Canis Major, and provides a fascinating glimpse into the death of massive stars and the beauty of cosmic phenomena. Planetary nebulae, form when a dying star dramatically sheds its outer layers, leaving behind a hot, dense core, typically a white dwarf star. These white dwarves are incredibly dense and hot. They emit high energy radiation, which ionize the gaseous out layer causing it to emit light – hence the beautiful irridescent display here..

Here the story is slightly different. This nebula spans around 30,000 light-years across, and its distinct “helmet-like” structure is created by the star at its core—a massive hot Wolf-Rayet star, designated WR 7. Wolf-Rayet stars are huge, rare, and have intense winds that blow away their outer layers, shaping the nebula around them.

This color palette gives Thor’s Helmet a dynamic and vibrant look, as different parts of the nebula shine in various shades depending on the density and composition of the gas. The overall result is a mesmerizing scene.

Like all planetary nebulae, Thor’s Helmet will eventually fade away as the central star exhausts its remaining fuel and ceases to ionize the surrounding gas. Over thousands of years, the nebula’s brilliant glow will dim, and it will disperse into the interstellar medium, enriching the surrounding space with elements that will be incorporated into future generations of stars and planets.

In the case of WR 7 stars, however, its fate will likely be a more spectacular one. As a Wolf-Rayet star, it is expected to eventually explode into a supernova, an event that will release vast amounts of energy and matter into the surrounding cosmos. This final explosion will be the culmination of the star’s life cycle and could lead to the creation of a black hole or a neutron star.

And let us take note that today is the First of March. Meteorological spring is upon us!

Figure 1 – Messier 7, Ptolemy Open Cluster, image take with iTelescope,net T72 in Chile. (c) DEWolf 2023

When you first get involved in amateur astronomy and start searching for Messier objects with a visual telescope, everything looks like a grey fuzzy and you think that there are four types of Messier objects: globular clusters, open clusters, nebulae, and galaxies. Never make a statement like that without checking the web first and needless-to- say there are formally six types: open clusters, globular clusters,  diffuse nebulae,  planetary nebulae, supernova remnants, and galaxies. So put a fine point on it!

Aesthetically, each form has its own appeal. And it’s like the old almond joy commercial: “Sometimes you feel like a nut. Sometimes you don’t.” Two years ago I encountered Messier 7 the Ptolemy (Open Cluster). Nestled in the deep Milky Way portion of Scorpius, we see it against an amazing array of stars!

Messier 7 is referred to as the Ptolemy Cluster in honor of the ancient Greek astronomer Claudius Ptolemy, who first recorded it in the 2nd century. Charles Messier cataloged it in 1764 as part of his famous Messier Catalog, a list of astronomical objects that helped astronomers distinguish between comets and fixed stars.

Messier 7 is an open star cluster situated approximately 980 light-years away from Earth. Open clusters, unlike globular clusters, consist of stars that are loosely bound together by gravity, and they are often found in the spiral arms of galaxies. M7 contains around 80 stars, and its most noticeable feature is its relatively young age, at only about 200 million years old a mere blink in the vast timeline of the cosmos.

I’ve imaged it with my Seestar 50s, not yet my Celestron Origin. This was a pretty pathetic image; so I am anxious to give it a try with the Origin this summer.

However, I did photograph it with the iTelescope T72 a fabulous 510 mm telescope (T72 3411 mm f/6.8 PlaneWave L-500 + FLI ML16200) in Deep Sky Chile at Rio Hurtado Valley, Chile. That is Figure 1 revealing Messier 7’s in all its celestial beauty. Now here is another important point. T72 is at 30°31’34.712″ South latitude and altitude 1710 m above sea level. M7 is the Messier object with the lowest declination, -34° 47′ 43″. It is always very low in New England skys. But it transits near the zenith in Chile. So clear skies high telescope altitude, and high celestial altitude. It’s a winning combination all around.  

Figure 1 – The Flaming Star Nebula IC 405 in Auriga, (c) DE Wolf 2025

There is a second wonderful flame Nebula in the winter sky, the Flaming Star Nebula, or IC 405, located in the constellation Auriga, the Flaming Star Nebula is a fascinating cosmic laboratory that offers insight into the birth and death of stars.

Like the Flame Nebula it is an emission nebula and is located is an emission nebula located approximately 1,500 light-years from Earth. It is named for its fiery, star-like appearance, which is created by the intense radiation emitted from a massive star at the heart of the nebula. This is the fundamental characteristic of emission nebulae, an intense radiation source, ionizing gases and causing them to emit light.

Indeed, at the center of this nebula lies AE Aurigae, a hot, blue giant star. This star, which is responsible for illuminating the surrounding gas and dust, is around 2 million years old—relatively young in cosmic terms—and is part of a group of stars known as the Auriga OB1 association. The star’s radiation ionizes the surrounding hydrogen gas, causing it to glow in brilliant hues of red and blue, creating the nebula’s striking appearance.

In addition to the red glow of ionized hydrogen, the nebula also displays blue and green hues, which are a result of other elements like oxygen and sulfur being excited by the radiation. These elements release light at specific wavelengths, contributing to the nebula’s colorful appearance. The nebula’s intricate, wispy structures are often seen as filaments or tendrils of gas and dust, creating the illusion of a burning star surrounded by an ethereal cloud.

Like so many deep-sky objects the Flaming Star Nebula was discovered in 1827 by Sir John Herschel. It is likely however, that it was seen by other observers earlier.

This was one of the first objects, where I recognized the need for at least a 60 min 360 frame exposure with my Celestron Origin. That is becoming my standard MO, and probably as I move into summer I will try longer exposures still!. The words for me are “flame out.” I see in IC 405 a sense of birthday candles being blown out! It was a nebula that I was unfamiliar with and in that sense a birthday surprise.

Figure 1 – The Horsehead Nebula, Barnard 33, Celestron Origin, a 60 min, 360 frame exposure. (c) DEWolf 2025.

Today I’d like to continue our tour of the Orion Molecular Cloud Complex with the Horsehead Nebula or Barnard 33. It is one of my all time favorites, indeed the favorite of many people. Figure 1 is an image that I took of it with my Celestron Origin, a 60 min, 360 frame exposure. You can see it clearly positioned close to the Flame Nebula

The Horsehead Nebula is a dark nebula, which means it is a dense cloud of gas and dust that obscures the light from stars and other objects behind it. Within this complex, the Horsehead Nebula stands out due to its distinct shape, which is formed by a dense, cold cloud of dust and gas. It spans about 3,000 light-years in length, with the Horsehead itself measuring about 1,500 times the size of our Solar System.

Despite being a dark nebula, the Horsehead is illuminated by the nearby star Alnitak, which is part of the Orion Belt. The radiation from Alnitak causes the surrounding gas to glow, contributing to the nebula’s glowing red appearance in many photographs. The Horsehead Nebula owes its distinctive shape to the way light interacts with the dust and gas in the region. The Horsehead silhouette is formed by a thick concentration of dust and gas that casts a shadow on the glowing emission nebula behind it. This shadowy region is particularly dense, blocking much of the light from the stars and other gas clouds in the area, and giving it its signature look.

In photos, you often see the Horsehead Nebula in a striking combination of red and black. The reddish hue comes from the ionized hydrogen gas in the nebula, which glows under the influence of ultraviolet light from nearby stars. The dark, black shape of the nebula contrasts with the glowing gas, making it appear almost like an otherworldly creature—hence the name “Horsehead.”

Within the nebula, there are regions of intense gravitational collapse, where the dust and gas are coming together to form protostars. These protostars are still in their early stages of development, but they are the building blocks of future stars.

The Horsehead Nebula was first noticed in the early 20th century. However, its “discovery” wasn’t as a result of visual observation with the naked eye, but rather through photographic techniques that were becoming more advanced during that time.

The nebula was first photographed in 1888 by the American astronomer Edward Emerson Barnard, who is often credited with its discovery. Barnard was one of the pioneers in using long-exposure photography to capture celestial objects, and it was this technique that allowed him to detect the faint, dark nebula in the Orion Molecular Cloud. And it was long exposure that was key to contrasting dark regions against faint brighter ones.

Indeed, we can consider Figure 2, which is an 18 min exposure that I took with my Seestar 50s. This image required considerable image processing using Topaz Camera AI and even so is a little fuzzy or noisy. With the Seestar I find that the images benefit from three processes: sharpening, denoising, and upscaling, where the AI increases the number of pixels and fills them in.

Figure 2 – Horsehead Nebula Seestar 50s 18 min exposure (c) DEWolf 2024

Basically, I think that you will agree that Figure 2 is less distinct and sharp than Figure 1. This begins a not so much complicated as subtle and shaded discussion of signal-to-noise. But let me just concentrate here on the issue of signal. After all the famous signal-to-noise ratio is brightness divided by something. How much brighter is the Celestron Origin than the Seestar 50s.

I heard in a YouTube tutorial that it was about 25 x brighter and I wondered where that came from. (This little mathematical calculation is for those of you who care!).

Suppose that the flux at the surface of the telescope objective is X (Watts/in²) then

(Light collected by Origin/light collected by Seestar) = X (5.98²-2.48²)/X 2² = 7.40.

This is because, Origin has a 5.98 ” objective and the camera occludes a 2.48 ” circle, while the Seestar has a 2 ” objective.

Next, we have the collection efficiency inside the telescope which is determined from the solid angle

(Collection eff. Origin/Collection eff. Seestar)=(f/#Seestar/f/#Origin)² =(5/2.2)² = 5.17

Finally, we have to consider that ratio of light collected by an Origin pixels to that collected by a Seestar pixel. This is given by the ratio of the areas of the two pixels

(Pixel Collection Origin/Pixel Collection Seestar) = (2.4 um x 2.4 um)/(2.9 um x 2.9 um) = .685

Thus, the brightness ratio  = .685 x 5.17 x 7.40 = 26. You heard it here first! Typically with my Seestar 50s I would take something like a 26 min exposure. You can capture this many photons in 1 min with the Celestron Origin. Astrophotography is a game of how many photons you can collect.