wimvb

And very likely, other countries will follow.

Is the loo black inside? a plethora of dark matter jokes comes to mind. But lets keep it clean.

It’s all relative [to the original, which uses high end Canon telephoto lenses].

One could do a budget version of this with samyang lenses and ASI1600 or ASI294MC.

A dragonfly actually. It’s called the dragonfly telephoto array, and is configured this way to study extremely faint structures. https://www.dragonflytelescope.org/

I think it will depend on how the mirrors are held in their cell. Either accurate adjustments of clamps, or silicone blobs to ”glue” the mirrors. Either way, as long as the mirrors move in tandem, it should be ok.

My ”record” is about 7 months. Two years ago, I had a break due to the lack of astro darkness, followed by a very bad autumn. Add to that a busted knee. I didn’t start imaging until after new year, but hadn’t missed more than an occasional night. The weather was just awful that year.

It’s a university project; always enough students handy to tinker with it.

Differential flexure. If you are careful enough and adjust the mirror clamps the same, then as long as the mirrors move the same, differential flexure may be manageable. But just another reason to have two mounts.

Unfortunately that seems the sad story of the MN190. I get the impression that people replace them sooner or later.

But you gents are thinking too small the current rig is at 2 times 24 telephoto lenses. What do you call that? (Other than asking for trouble)

It gets twice the amount of data in one night, AND has the advantage of imaging two objects at the same time, or doing simultaneous mosaicing. Whatever you call it, it makes more sense than spending time and money to fix this

If I ever go for a dual rig, it may very well be with 2 * MN190. But not on the same mount. Btw, does @Tomatobro have the original focuser on his MN190, or an upgrade?

Tweak nr 1, enhanced contrast and sharpened the core. I'm not quite sure which I like best.

Thanks, Peter. That was the original intention when aiming for this target. But unfortunately at the cost of the core. I think I have that fixed now. I had hoped to get finer detail in the core, but Northern European skies don't cooperate.

The very first scope I bought (SW 150PDS) had issues on arrival. I attached the finder scope in its shoe, but no matter what I tried, I couldn’t get it aligned with the main scope. Even with a 25mm eyepiece, views through the scope were way off what I saw through the finder. I was about to return the 😖😡👿🤬 thing. Then I checked collimation ... I used the end plug of a 32 mm drainage pipe as my first collimation cap. Just drilled a small hole in its centre. It fitted perfectly in a 1.25” eyepiece adapter. Collimation perhaps wasn’t spot on after that, but certainly a lot better than before.

Last year I collected data for M94 but I never managed to create a pleasing image from it. Early April I collected new luminance and Ha. M94 has a very bright core, so in addition to the 120 s subs from last year, which had a burnt out core, I collected 60 s subs, this year, and created an HDR composition. With the Ha, I now have a presentable image. LRGB was collected with my MN190 and ZWO ASI174MM-Cool + ZWO LRGB filters short exposure L, and Ha were collected with the MN190 and ZWO ASI294MM-Pro + Baader 7 nm Ha filter RGB: 115 x 240 s (460 minutes) L: 97 x 120 s and 60 x 60 s (254 minutes) Ha: 40 x 300 s (200 minutes) Total integration time, approximately 15 hours M94 (ngc 4736) is a spiral galaxy in the constellation Canes Venatici, at a distance of about 16 million light years. From Wikipedia: "M94 has an inner ring with a diameter of 70 arcseconds (″) (given its distance, about 5,400 light-years (1,700 pc)) and an outer ring with a diameter of 600″ (about 45,000 light-years (14,000 pc)). These rings appear to form at resonance points in the disk of the galaxy. The inner ring is the site of strong star formation activity and is sometimes referred to as a starburst ring. This star formation is fueled by gas driven dynamically into the ring by the inner oval-shaped bar-like structure.[9] A 2009 study[10] conducted by an international team of astrophysicists revealed that the outer ring of M94 is not a closed stellar ring, as historically attributed in the literature, but a complex structure of spiral arms when viewed in mid-IR and UV. The study found that the outer disk of this galaxy is active." Some of the "complex structure of spiral arms" that Wikipedia mentions is visible in the inverted superstretched luminance data (see below). There are plenty of small faint galaxies in the background, but relatively few of them have information in Simbad, other than location and brightness (flux). Although I did find distance information on some: SDSS J125127.47+410225.7: a galaxy in a compact group of four galaxies (SDSSCGB 5669), with a redshift of 0.369. This puts it at about 4.8 billion light years from the Milky Way. SDSS J124938.39+411345.5 (upper right) is an emission line galaxy at a distance of 2.5 billion light years

I don't use ascom, but in the Linux eqmod driver (indi), I have to clear the mount configuration whenever the flip doesn't work. That always solves the problem. Perhaps something similar is happening here?

Thank you, Peter.

I used to have the same setup, with the wobbly aluminium tripod. The first improvement I made was to stiffen the tripod legs. The second improvement I made was to buy an AZ-EQ6. As you already noted, the mount is way above its load limit. The scope alone ways 5 kg, without camera or guide scope. The eq3 is a nice little mount that can perform very well, when loaded and tuned correctly. I've seen some amazing images where this little mount was used, here on sgl. If you put a small refractor on it, or just a camera with lens, you can get excellent results. But the combination eq3 with 150pds should never be marketed as an imaging kit. The 150pds needs an (h)eq5 at least. If you can't upgrade the mount, I suggest you put the 150pds in storage, and image with a lense or small refractor.

This is a rework of data from 2019. More experience in processing allowed me to pull a little more out of the data. A little more colour, a little more detail and a few more faint fuzzies in the background. The faintest of these are 3.2 Gly distant. The galaxy cluster at the lower tip of the Needle is"only" 2.3 billion light years distant. There are also a few QSO's in the field of view. Next season, I may revisit this galaxy and try to go deeper. Ngc 4565 itself is some 38 - 50 million light years from us (the larger estimates are from redshift measurements). It is a spiral galaxy with a distinct box-like bulge. The outer edges of the galaxy's disc are slightly warped, which is an indication that it is interacting with another galaxy; possibly ngc 4562, the smaller galaxy to the lower right of ngc 4565, or perhaps IC3571, that "smudge" straight up from the bulge and to the left of the upper tip of ngc 4565. Ngc4565 has an angular size of 13.8 arc minutes. If we assume a distance of 38 Mly (wikipedia), this means that the galaxy is about 153 000 light years across, some 50% larger than our own Milky Way. Essentials: telescope + camera: SW MN190 + ZWO ASI174MM-Cool with ZWO LRGB filters Only 5.3 hours of data, of which 100 minutes Luminance Processedin PixInsight

Ic 3355, 3363, and 3393 are all about 16-18 Mpc distant (multiply Mpc by 3.26 to get Mly). According to vizier.

That would be a nice project for @gorann next season. But in all fairness, I think the galaxy would get lost in the wide fov

No worries. 113.5 hours images are rare, but they do exist. It is said that for every magnitude of sky darkness that you lose, you need to multiply your integration time by 2.5. In order to show that tidal tail, we would probably need those 100+ hours.

Not necessarily so. The half meter mirror is quite slow (f/8.2). But the camera that they used has huge pixels, 9 micrometer. My previous configuration with 5.68 um pixels and an f/5.3 scope, had equivalent imaging efficiency. But at the cost of loss in detail that I could capture. Btw, there is some controversy regarding this galaxy and its tidal stream. Using the Dragonfly telescope, Van Dokkum and co-workers also tried to catch it, with different results. https://phys.org/news/2019-07-stellar-stream-galaxy-ngc-morphology.html