Our Beautiful Universe - Photos and Videos

[collinsmark]

The Cigar Galaxy, also called M82, in the constellation Ursa Major, imaged from my back patio in April, 2022. M82 is a starburst galaxy, meaning it is undergoing an exceptionally high rate of star formation. The galaxy is about 12 million light-years away.

The term "starburst" is also the name of type of candy. Try as I might, I can't determine for certain which came first: the name of the candy or the astrophysics term. It would make sense that the astrophysics term came first, but I don't know.

Speaking of candy, I remember "candy cigarettes" as a child (different from the "Starburst" candy). They looked like cigarettes, but they were actually hard candy. Children, including my young and naive self, would pretend to smoke while eating them. They are not made anymore. That's probably for the best.

Here's a zoomed in crop of the image, showing a little more detail I struggled to eke out of the data.

Even crazier than candy cigarettes were the exploding cigars that were popular from the beginning through the middle of the 20th century. These were explosive caps that could be put into cigars that would explode as a practical joke. Could you imagine that today? "Hey, quick, come watch: we're going to cause a chemical explosion to blow up just inches in front of Bob's face. As a joke!" They don't make those anymore. 'Probably for the best.

Equipment:
Meade 10" LX200-ACF on an equatorial wedge.
ZWO RGB filter set (for color data).
Optolong L-Pro filter (for luminance data).
Baader 3.5 nm Hα filter (for the hydrogen emission data, for that extra, red punch).
Off-axis guider with ZWO ASI174MM-Mini.
ZWO ASI6200MM-Pro as main camera.

Software:
Nighttime Imaging & Astronomy (N.I.N.A.)
PHD2 guiding (of course)
PixInsight
Topaz Labs Denoise AI
Topaz Labs Sharpen AI

Usually I add the hydrogen alpha (Hα) to the RGB data before combining the luminance data. But in this image, I added the Hα after constructing the LRGB image. This way, those red squirts pop out a little better.

Integration:
Bortle class 7 (maybe 8) skies
All subframes binned 3×3
L-Pro: 110×240sec = 7.33 hours
R: 60×240sec = 4.00 hours
G: 49×240sec = 3.27 hours
B: 61×240sec = 4.07 hours
Hα: 49×600sec = 8.17 hours
Total integration time: 26.83 hours

 

[DennisN]

(I've got some stacking to do for the Moon itself):

Here's a stacked photo of the Moon during the partial lunar eclipse 16 May 2022:
(the Moon was very low on the horizon at the moment)

Camera and lens: Sony A6000 + Tokina 400mm f/6.3 + 2x teleconverter.
Camera settings: 1/1000s exposure, ISO 1600.
Stacked with AutoStakkert (25% best of 79 photos).
Some postprocessing in Photoshop (levels adjustment and contrast adjustment).

 

[Oldman too]

Children, including my young and naive self, would pretend to smoke while eating them. They are not made anymore. That's probably for the best.

Great images!

Same here, sadly as a society, we are slow learners.
https://www.amazon.com/dp/B007FXC14S/?tag=pfamazon01-20

Also: https://www.nature.com/articles/d41586-022-01420-9 I hate the concept of "unsustainable"

In the interest of thread continuity, From APOD, 05/27. https://www.nasa.gov/image-feature/goddard/2022/hubble-captures-pair-of-star-forming-spirals

 

[pinball1970]

Big meteor shower on Monday, you will have a good view in the states according to NASA. Comet SW3 breaking up.

https://www.telegraph.co.uk/science...ids-meteor-shower-peak-may-2022-how-watch-uk/

 

[Oldman too]

Big meteor shower on Monday, you will have a good view in the states according to NASA. Comet SW3 breaking up.

https://www.telegraph.co.uk/science...ids-meteor-shower-peak-may-2022-how-watch-uk/

Some more detail on the show.
https://www.amsmeteors.org/2022/05/possible-meteor-outburst-on-may-3031/

 

[pinball1970]

Some more detail on the show.
https://www.amsmeteors.org/2022/05/possible-meteor-outburst-on-may-3031/

My source who is also a pf member @Astranut (and gives me these space tasty tit bits) said all was cloudy here in the UK, Manchester between 1am-5am.
Any luck in the States I wonder?

 

[Oldman too]

Any luck in the States I wonder?

Locally speaking, unless cloud cover counts as luck, nope.
This site is particularly useful for an astronomical "heads up" including weather stats for particular events as well as other viewing details. https://www.timeanddate.com/eclipse/lunar/2022-november-8
As you will see, the western U.S. gets to share a total lunar eclipse with New Zealand, Japan etc. on that particular date. Locally speaking, I can statistically expect an 80% chance of clouds for the event (the optimist in me sees a 20% chance of a good show though).

 

[Devin-M]

...been a while... made it out last night to image...

Sombrero Galaxy (M104)
Distance: 31 Mly Diameter: 49000 ly
Camera: Nikon D800
Scope: 6" diameter Maksutov Cassegrain
Focal Length 2180mm

 

[Devin-M]

A couple more shots of the venerable Star Adventurer 2i equatorial mount overloaded probably around 4x above the weight limit (it’s a very capable little equatorial mount for the $449USD price tag)... I think you’re only supposed to have 10-12lbs on there but it’s probably supporting around 40+ lbs as pictured… the 2nd camera with 600mm lens and video panhead is there purely as counterweight…

 

[DennisN]

I think you’re only supposed to have 10-12lbs on there but it’s probably supporting around 40+ lbs as pictured… the 2nd camera with 600mm lens and video panhead is there purely as counterweight

Put a little more on it and it will turn into a black hole. :)

 

[Devin-M]

Put a little more on it and it will turn into a black hole. :)

Fun fact: the Sombrero Galaxy contains the nearest black hole to the Earth that has more than 1 billion solar masses…

 

[collinsmark]

M101, the Pinwheel Galaxy, captured from my back patio in April, 2022. M101 is a large spiral galaxy, about twice the size (more or less) of our own Milky Way. It's about 20 million light-years away, and can be seen in the constellation Ursa Major.

Something is interesting regarding M101's central, supermassive black hole (SMBH), assuming it even has one (most galaxies do). It lacks the typical radio and x-ray emissions indicative of a SMBH, leading some to suspect that it might not have a SMBH at its center. Whatever the case, it's a curiosity.

Equipment:
Meade 10" LX200-ACF on an equatorial wedge.
Off-axis guider (OAG) with ZWO ASI174MM-mini
ZWO RGB filter set for color data.
Optolong L-Pro filter for luminance data.
Baader 3.5 nm Hα filter for those deep red, hydrogen regions.
ZWO ASI6200MM-Pro main camera.

(Here's a zoomed in crop showing showing some central detail.)

Software:
Nighttime Imaging 'N' Astronomy (N.I.N.A.)
PHD2 guiding (of course)
PixInsight
Topaz Labs Denoise AI
Topaz Labs Sharpen AI

M101's appearance is reminiscent of a pinwheel, hence its name. I fondly remember being fascinated by the aerodynamics of pinwheels when I was a bit younger. I would start with a couple of squares of colored paper. I would then carefully fold and cut the pieces of paper into pinwheel shapes, before attaching the "wheels" to plastic rods: typically drinking straws. Then I would hold one pinwheel in each hand, extended upward and outward, and gleefully run around in circles like a freak. And that was just a couple of weeks ago.

Integration:
Bortle class 7 (maybe 8) skies
All subframes binned 3×3.
R: 46×5min = 3.83 hours
G: 35×5min = 2.92 hours
B: 53×5min = 4.42 hours
L-Pro: 90×5min = 7.5 hours
Ha: 23×10min = 3.83 hours
Total integration time: 22.5 hours

 

[Andy Resnick]

Over here, I'm mostly imaging M13- the Great Globular Cluster in Hercules. Last week I learned that just before M13 rises into a decent altitude, Hoag's Object is in a favorable position. This past weekend was mostly clear, so I had a few nights to try and image it. Since M13 tests my skills, I again put them to the test with Hoag's Object:

It might not look like much, but the faint dot in the center with a (I think) barely-visible ring is it. 80 minutes of viewing time (over 4 days) with a 800/8 lens (equivalent to a 100mm refractor) and Nikon D810 body mounted on a Losmandy GM8, Gemini 2 Controller/Driver.

I'm definitely pleased, considering Hoag discovered this object in the 1950's (instead of the ancient times a la Messier objects) meaning my imaging hardware compares a lot worse to what was used to discover the objects. I know I can easily detect down to at least magnitude 15 so I knew I could detect the central peak, but I wasn't sure I could detect, much less resolve, the ring as distinct from the central peak.

Additional imaging time on this will likely have to wait until next year- we have a few days of rain/clouds forecast, then the moon interferes for a few days and then it's not really viewable from my location. I'm still concentrating on M13, at least until M57 (Ring nebula) moves into position.

 

[collinsmark]

I'm definitely pleased, considering Hoag discovered this object in the 1950's (instead of the ancient times a la Messier objects) meaning my imaging hardware compares a lot worse to what was used to discover the objects. I know I can easily detect down to at least magnitude 15 so I knew I could detect the central peak, but I wasn't sure I could detect, much less resolve, the ring as distinct from the central peak.

Nice!

You know it's going to be a tough target when even the best Hubble (HST) image looks noisy.

 

[Devin-M]

Hoag's Object is in a favorable position

Has anyone calculated the odds of there being a 2nd ring galaxy visible within the ring of the nearer ring galaxy?

 

[DennisN]

I was browsing flickr and stumbled upon a guy who does some very creative and beautiful photography (incl. astrophotography). His flickr photostream is well worth a visit: Roberto Bertero.

He doesn't allow hotlinking so I can't post pictures here, but I'll post some links to photos:

• Ursa Major above Mont Blanc
• Milky Way in the Mirror*
• Grand Assaly and Milky Way
• A Prayer to Heaven
• (and here's a very beautiful non-astro photo: The Value of a Single Instant)

* The "Milky Way in the Mirror" photo is actually a bit similar to what I've been thinking about myself, i.e. photographing the Milky Way reflected in water. Hopefully I will have the opportunity to do it this summer. I'm thinking of doing it over the ocean and/or over a small lake somewhere. But I have to pick a perfect, calm day for it if I want to get a clear reflection in the water.

 

[collinsmark]

The Antenna Galaxies discreetly imaged from my back patio in May 2022. Here we see NGC 4038 (top left) in her native habitat devouring NGC 4039 (bottom right), her gravitationally chosen mate, in a final cosmic embrace. The two galaxies are becoming one while producing a burst of new stars. This starburst phase is caused in part by the galactic scale howls of sound waves pulsing through the intragalactic gas and dust, an inevitable process of the intimate merger.

The Antenna Galaxies get their name from the trails of stars, gas, and dust ejected from the galaxies' passionate dance, which resemble an insect's antenna. Together, in terms of size, the pair of galaxies are in the same ballpark as our own Milkyway Galaxy. New data suggest they are about 45 million light-years away (previously thought to be about 65 million light-years). They can be peeked at from Earth in the constellation Corvus.

(Crop showing a bit more detail in the center)

Equipment:
Meade 10" LX200-ACF on an equatorial wedge.
Off-axis guider (OAG) plus guide camera.
Optolong L-Pro filter for luminance data.
ZWO RGB filter set for color data.
Baader 3.5 nm Hα filter (for that extra red, present in starburst regions).
ZWO ASI6200MM-Pro main camera.

Software:
Nighttime Imaging 'N' Astronomy (N.I.N.A.)
PHD2 Guiding (goes without saying)
PixInsight
Topaz Labs Denoise AI
Topaz Labs Sharpen AI

This was a rather tough target to image, mostly for terrestrial reasons: It's a significantly southern object given my northern latitude, right above where most of my light pollution and glare comes; dust motes and gradients for which flat frames did not fully compensate; and lots and lots of clouds, haze, and fog. Lot's of haze, btw. Transparency was awful almost every night (if not completely cloud covered) for the whole of May. It was as if nature here on Earth conspired to give NGC 4038 and NGC 4039 their privacy. You might think that over 30 hours of integration time is a lot (it's a lot), but this target could have used more. Well, I guess I can gather more data next year, I suppose.

Integration:
Bortle Class 7 (maybe 8) skies.
All subframes binned 3×3.
L-Pro: 83 × 5min = 6.92 hours
R: 38 × 5min = 3.17 hours
G: 80 × 5min = 6.67 hours
B: 77 × 5min = 6.42 hours
Hα: 51 × 10min = 8.5 hours
Total integration time: 31.67 hours

 

[Drakkith]

This was a rather tough target to image, mostly for terrestrial reasons: It's a significantly southern object given my northern latitude, right above where most of my light pollution and glare comes; dust motes and gradients for which flat frames did not fully compensate; and lots and lots of clouds, haze, and fog.

I feel you. I took my gear out a few days ago and had nothing but problems. Awful transparency plus a full moon meant that I could barely even find my target, Pickering's Triangle. 20 second exposures with an F/5.5 refractor and 6x binning gave me barely enough to find and center it. Then my PHD guiding software crapped out about 20 minutes into the session and I spent another 20 minutes figuring out how to use my normal imaging software (Maxim DL) to guide. Then another 20 troubleshooting why it wasn't correcting declination drift.

Finally got all that figured out, started my imaging session, came back about 45 minutes later to check on everything and every exposure was unusable because of flexure issues. Which hadn't shown up before with the exact same setup on the exact same target I've imaged before...

Issues like this are a regular occurrence for me. So frustrating that I've contemplated selling all my gear several times.

 

[bruha]

Hello, I attach cutout of recent sun with green filter image (no sun spots nowadays.. ).

Lot of succes

 

[bruha]

Hello,
yesterday I catch some sun spots-group of 3 bigger and
second group of more small spots (looks as archipelago.. )
attached is in white and with green sun filter as well

Lot of succes

 

[Andy Resnick]

M13, imaged over the past month or so: 800/8, DX frame, 8s subs, 7.5 hr total integration time, stacked and post-processed in APP:

And a 200% crop:

Definitely pleased with the well-controlled primary and chromatic aberrations of this lens. The 'purple fringing' that appears when used at full aperture is gone, and the PSF themselves have decreased from 4 pixels to 3.5 pixels, compared to imaging at f/5.6.

APP has a 'star calibration' function that helps correct for what I will call 'white balance problems' caused by light pollution. I'm not exactly sure how it works, but it seems to work well!

Onwards to M57...

 

[phinds]

Professional photographer and amateur astronomer captured time-lapse (less than a second) of the ISS transiting the sun.

https://www.bbc.com/news/uk-england-northamptonshire-61856975

 

[timmdeeg]

M13, imaged over the past month or so: 800/8, DX frame, 8s subs, 7.5 hr total integration time, stacked and post-processed in APP:

View attachment 303112

And a 200% crop:

View attachment 303114

Definitely pleased with the well-controlled primary and chromatic aberrations of this lens. The 'purple fringing' that appears when used at full aperture is gone, and the PSF themselves have decreased from 4 pixels to 3.5 pixels, compared to imaging at f/5.6.

APP has a 'star calibration' function that helps correct for what I will call 'white balance problems' caused by light pollution. I'm not exactly sure how it works, but it seems to work well!

Onwards to M57...

Hi Andy,

thanks for these images. What interests me is the occurrence of quadratic stars if I zoom into your original image (with two fingers on the iPad), whereas your beautiful 200% crop shows round stars.

I have observed this phenomenon too, see below 331x30" frames stacked with DeepSkyStacker, taken with my 102 mm / 570 Refraktor. The first image is already a crop (the original view angle is 3.5°) and the second is a very deep crop into the center.

Searching the web
http://www.sbig.de/universitaet/glossar-htm/sampling.htm
quadratic stars are due to undersampling and as recommended I will try to improve that by activating Dithering during taking the pics and eventually Drizzle while stacking.

So when I saw your crop I got excited. How did you get the non-quadratic stars? Simple question, please bear in mind I'm a beginner, I will appreciate any comments.

 

[collinsmark]

Hi Andy,

thanks for these images. What interests me is the occurrence of quadratic stars if I zoom into your original image (with two fingers on the iPad), whereas your beautiful 200% crop shows round stars.

I have observed this phenomenon too, see below 331x30" frames stacked with DeepSkyStacker, taken with my 102 mm / 570 Refraktor. The first image is already a crop (the original view angle is 3.5°) and the second is a very deep crop into the center.

Searching the web
http://www.sbig.de/universitaet/glossar-htm/sampling.htm
quadratic stars are due to undersampling and as recommended I will try to improve that by activating Dithering during taking the pics and eventually Drizzle while stacking.

So when I saw your crop I got excited. How did you get the non-quadratic stars? Simple question, please bear in mind I'm a beginner, I will appreciate any comments.

The typical solutions to combat undersampling issues are (not necessarily in any order):

• If your optical train is presently using a focal reducer, don't use the focal reducer for the target in question. Just remove the focal reducer from the optical train. (If you're using a focal reducer/field flattener combo, remove that too. You're probably going to be significantly cropping the image anyway, so stars at the edge of the field don't really matter that much since they're ultimately going to be cropped out.)
• If you're using a monochrome camera that supports binning, don't bin as much or don't bin at all.
• Use a Barlow lens to increase the effective focal length. (This also applies to brand-name "Barlow" lenses such as Tele Vue's Powermates. 'Same concept.)
• Switch to a telescope with a longer focal length.
• Switch to a camera with smaller pixels.
• If you don't have the ability to change hardware, dither you subframes when acquiring, and use the "Drizzle" algorithm when stacking. You've already mentioned this option in your post above.

 

[Andy Resnick]

Hi Andy,

thanks for these images. What interests me is the occurrence of quadratic stars if I zoom into your original image (with two fingers on the iPad), whereas your beautiful 200% crop shows round stars.

I have observed this phenomenon too, see below 331x30" frames stacked with DeepSkyStacker, taken with my 102 mm / 570 Refraktor. The first image is already a crop (the original view angle is 3.5°) and the second is a very deep crop into the center.

Searching the web
http://www.sbig.de/universitaet/glossar-htm/sampling.htm
quadratic stars are due to undersampling and as recommended I will try to improve that by activating Dithering during taking the pics and eventually Drizzle while stacking.

So when I saw your crop I got excited. How did you get the non-quadratic stars? Simple question, please bear in mind I'm a beginner, I will appreciate any comments.

Thanks for the kind words!

I'd like to help, but I'm not sure I understand what you mean by 'quadratic stars'- are you referring to the image shown on the link you posted? Looking at the right image you posted I can guess, but I want to make sure I understand your question. :)

Two more questions: is your telescope a 102mm diameter, 570mm focal length refractor? And finally... what camera/sensor are you imaging with?

 

[timmdeeg]

The typical solutions to combat undersampling issues are (not necessarily in any order):

• If your optical train is presently using a focal reducer, don't use the focal reducer for the target in question. Just remove the focal reducer from the optical train. (If you're using a focal reducer/field flattener combo, remove that too. You're probably going to be significantly cropping the image anyway, so stars at the edge of the field don't really matter that much since they're ultimately going to be cropped out.)
• If you're using a monochrome camera that supports binning, don't bin as much or don't bin at all.
• Use a Barlow lens to increase the effective focal length. (This also applies to brand-name "Barlow" lenses such as Tele Vue's Powermates. 'Same concept.)
• Switch to a telescope with a longer focal length.
• Switch to a camera with smaller pixels.
• If you don't have the ability to change hardware, dither you subframes when acquiring, and use the "Drizzle" algorithm when stacking. You've already mentioned this option in your post above.

Thanks for your advice!

Yes I'm using a 3" 0.79 reducer and have never tried without it. My Sony A7iii is a full format camera with pixel size 6 micrometer. I have no idea how much of the image will still be suitable. I'll check, thanks again.

 

[timmdeeg]

Thanks for the kind words!

I'd like to help, but I'm not sure I understand what you mean by 'quadratic stars'- are you referring to the image shown on the link you posted? Looking at the right image you posted I can guess, but I want to make sure I understand your question. :)

Two more questions: is your telescope a 102mm diameter, 570mm focal length refractor? And finally... what camera/sensor are you imaging with?

Please see my answer to @collinsmark .

I am just curious that zooming in your first image yields something completely different than you 200% crop. Is it perhaps a matter of processing?

 

[Devin-M]

I was wondering about my optical tube focus so I wheeled it out for some daytime sharpness test shots at 2130mm f/14.2 Maksutov-Cassegrain on a Nikon D800 35mm full frame sensor, manual focus, typical test shots were 450iso at 1/800th sec, raw converted with adobe lightroom settings...

iPhone 11 "1x" lens (standard not wide or zoom), full frame:

Full Frame:

100% Crop:

Full Frame:

100% crop:

Full Frame:

100% crop:

100% Crop, Sombrero Galaxy, single unstacked subframe 90seconds @ 6400iso for comparison:

Fisherman's hand 100% crop again for comparison...

iPhone full frame yet again for comparison...

 

[Andy Resnick]

Please see my answer to @collinsmark .

I am just curious that zooming in your first image yields something completely different than you 200% crop. Is it perhaps a matter of processing?

I understand.

Yes, your problem is 'undersampling', or put another way, your optical system resolution is sensor-limited: the point spread function (PSF) produced by your optics is about the same size as, or smaller than, a pixel. Since your sensor is quite reasonable (some cooled cameras have 15 um pixel sizes; cell phone camera pixels typically are, by comparison, 3 um or less), I agree with collinsmark's suggestion to remove the focal reducer and possibly add a Barlow lens. Both of these will have the effect of magnifying the PSF (but also decreasing the field of view and increasing the f/# of your optics) making your system lens-limited and giving you nice round stars.

I would also suggest, if the cost of a Barlow lens is prohibitive, to get a phone adapter for your scope and try using that sensor. And, dithering/drizzle are (AFAIK) other zero-cost approaches.

What you notice on my posted images is also undersampling: I have to downscale the original image to about 20% to satisfy PF's posting rules. Since in my original image the PSF is about 4 pixels across, the downscaled image has effectively a PSF that is 0.8 pixels in size, so when you zoom in on that you can easily see the pixilation.

To be sure, the original image is pixellated also- here's a 600% crop of a (small) part of the original image- note that I did not perform any interpolation step after upscaling, to preserve the image structure:

Scaling 'only' to 200% wasn't sufficient to bring out the pixilation.

My last comment is that you are currently imaging at f/4.2 (if I did the calculation correctly). I'm somewhat surprised that your undersampling is so bad because when I image at f/2.8 (400mm) I don't get any undersampling- even when I image at f/1.4 (105mm) I don't get any undersampling effects. To be sure, seeing conditions in Cleveland are a good argument not to construct any local observatories- the size of my PSFs are comparatively large and entirely due to clear-air turbulence. Call it 'natural dithering' :)

Hope this helps- post results after you've tried a few things!

 

[Devin-M]

I understand.

Yes, your problem is 'undersampling', or put another way, your optical system resolution is sensor-limited: the point spread function (PSF) produced by your optics is about the same size as, or smaller than, a pixel. Since your sensor is quite reasonable (some cooled cameras have 15 um pixel sizes; cell phone camera pixels typically are, by comparison, 3 um or less), I agree with collinsmark's suggestion to remove the focal reducer and possibly add a Barlow lens. Both of these will have the effect of magnifying the PSF (but also decreasing the field of view and increasing the f/# of your optics) making your system lens-limited and giving you nice round stars.

I would also suggest, if the cost of a Barlow lens is prohibitive, to get a phone adapter for your scope and try using that sensor. And, dithering/drizzle are (AFAIK) other zero-cost approaches.

What you notice on my posted images is also undersampling: I have to downscale the original image to about 20% to satisfy PF's posting rules. Since in my original image the PSF is about 4 pixels across, the downscaled image has effectively a PSF that is 0.8 pixels in size, so when you zoom in on that you can easily see the pixilation.

To be sure, the original image is pixellated also- here's a 600% crop of a (small) part of the original image- note that I did not perform any interpolation step after upscaling, to preserve the image structure:

View attachment 303198

Scaling 'only' to 200% wasn't sufficient to bring out the pixilation.

My last comment is that you are currently imaging at f/4.2 (if I did the calculation correctly). I'm somewhat surprised that your undersampling is so bad because when I image at f/2.8 (400mm) I don't get any undersampling- even when I image at f/1.4 (105mm) I don't get any undersampling effects. To be sure, seeing conditions in Cleveland are a good argument not to construct any local observatories- the size of my PSFs are comparatively large and entirely due to clear-air turbulence. Call it 'natural dithering' :)

Hope this helps- post results after you've tried a few things!

is that a green star in the top right?

 

[Devin-M]

I wonder what's causing my focusing issue... if I focus on a pigeon's eyeball in daylight I can distinguish edges that appear 5 or 6 pixels wide but then at my last astrophotography shoot I had stars that were 26 pixels wide... I used a bahtinov mask to focus, but maybe I was just bad at it or maybe the mirror slap is causing some persistent shake even though I use a 3 second shutter delay after mirror flip up? maybe the whole thing is wobbling since I'm putting 40 lbs on a mount only designed to hold 10-12lbs with no star tracking? maybe temperature change of the front lens after I get focused but before I get on target which can take up to an hour since I have to do plate solving through my cell phone with poor reception? maybe it's the atmosphere since the star wasn't all that high above the horizon at the time?

 

[Drakkith]

maybe the whole thing is wobbling since I'm putting 40 lbs on a mount only designed to hold 10-12lbs with no star tracking?

Imaging at 2000+ mm focal length with no tracking on an overloaded mount? I'm amazed you can get 30 second subs, let alone 90.

 

[Andy Resnick]

is that a green star in the top right?

Possibly? I'm color blind... can't say for sure.

 

[Andy Resnick]

I wonder what's causing my focusing issue... if I focus on a pigeon's eyeball in daylight I can distinguish edges that appear 5 or 6 pixels wide but then at my last astrophotography shoot I had stars that were 26 pixels wide... I used a bahtinov mask to focus, but maybe I was just bad at it or maybe the mirror slap is causing some persistent shake even though I use a 3 second shutter delay after mirror flip up? maybe the whole thing is wobbling since I'm putting 40 lbs on a mount only designed to hold 10-12lbs with no star tracking? maybe temperature change of the front lens after I get focused but before I get on target which can take up to an hour since I have to do plate solving through my cell phone with poor reception? maybe it's the atmosphere since the star wasn't all that high above the horizon at the time?

Is there a way to securely mount your optics to a stable surface and perform some 'calibration' tests? I'm thinking about distant lights that approximate point sources or something similar. Atmospheric distortions will be very noticeable, but doing this in the early morning when the air is quiet might give you some clues.

 

[Devin-M]

I’m thinking of trying a 2nd round of focusing with the bahtinov mask after I get the telescope pointed at the target as that will give the telescope an extra hour or so to reach a stable temperature and also choose a target much closer to the zenith that way I’ll be shooting through less atmosphere.