Laurin Dave

The Heart Nebula in HaR_OiiiG_OiiiB. Imaged through my Esprit 150/SX-46 with piggybacked Esprit 100/ASI1600mm on a Mesu 200 from late September to mid November. Ha and RGB through the 150 and Ha and Oiii through the 100. This is a four panel mosaic totalling 52hours Ha, 16hrs Oiii and 16hrs RGB, I'd like to have got more RGB and Oiii and added Sii but progress has been clouded out for the last few weeks and I feel the need to move on to new targets. Processed in Pixinsight and Photoshop with use made of the StarNet++ module in Pixinsight The Heart Nebula, IC 1805, Sharpless 2-190, lies some 7500 light years away from Earth and is located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. It was discovered by William Herschel on 3 November 1787. It is an emission nebula showing glowing ionized hydrogen gas and darker dust lanes. The brightest part of the nebula (a knot at its western edge) is separately classified as NGC 896, because it was the first part of the nebula to be discovered. The nebula's intense red output and its morphology are driven by the radiation emanating from a small group of stars near the nebula's center. This open cluster of stars, known as Melotte 15, contains a few bright stars nearly 50 times the mass of our Sun, and many more dim stars that are only a fraction of our Sun's mass. Thanks for looking Dave

Those stripes look like walking noise? are you dithering? Most apparent on the Oiii as the signal is weak and the stretch most extreme .. the glows on the right are amp glow which properly matched darks will remove

It’s also best to do the darks with the camera off the scope, it’s 10mm adapter on, the sensor cap on and facing into a desk to stop any light leaks you might get if it’s in the scope .. Darkflats are just darks with the same exposure temperature etc as your flats.. obviously if you take the camera off to do them you mess your flats up so I have a library of darks to suit my flats and lights exposures.. they are a year old now and still work well.. hth Dave

Carole.. just a thought but maybe focuser/camera droop as they turn upside down Dave

Very nice Ceph, if you weren’t aware with this camera it’s best to use matched darks (time, temperature, gain,offset) for both lights and flats.. no bias. Might sort out the stripes on the low signal subs.. Dave

Both very nice, like others I prefer the HSO, but some details are to me clearer in the SHO, if it were mine I’d tone down the green with selective colour.. I’d also do an HOO version Dave

That happened to me at Barry Island once 😕

Hi Alan Like Goran I have Esprit 150 and Esprit100 but have them piggybacked. The 150 has an SX-46 CCD on it and the 100 an ASI1600 cmos.. the 100 combo has a slightly larger fov and I aligned the scopes with shims.. image scales are similar at 1.5/1.2 arcsec/pixel. Both controlled by SGPro with the 150 as the master.. I dither and use an OAG and so lose 15-20% of the subs from the 100 but that’s still 80% more data than I’d get from one scope.. I have this setup to make the most of the UK’s cloudy skies.. and for Nebula take Ha, Oiii, Sii through the 100 and RGB Ha though the 150, for galaxies RGB through the 100 and Lum through the 150. what is your objective? Is it a close up and a wider field image to give it context ? If so you may find that having the scopes aligned doesn’t give the optimum framing for one or the other.. ( will depend on how large the larger fov is) is it to combine Narrowband or lum with colour at similar image scales? Etc Unless you are doing the later then given your excellent skies I’d just run two setups if you can get two mounts in your observatory.. more flexible simpler and you can still image the same target in different wavelengths.. Dave

Hi David I have encountered something similar with Mesu Sitech SGPro and Platesolve.. It does the flip ok but if, as last night the target is very close to the zenith/meridian then on target commence the mount will go to the correct side, take a plate solve image then slew to the other "incorrect' (ie just about to hit the pier) side and fail to solve.. I suspect its to do with Sitech settings conflicting with SGPro but have no idea which ones.. I get around it by switching off slew and centre and doing a manual plate solve very close to the target and then a manual slew to it.. When it gets to 30mins or so beyond the meridian it all works fine Dave

Another thing to maybe check is whether the USB ports on your laptop are timing out under power save..

Be interesting to see Rodd, maybe the sky background with lrgb will masks .. my mates instance was with Astrodon Oiii and asi1600

Rodd, a friend of mine had this happen the other day with Pixinsight, I referred him to Vliav’s response and he sorted it by changing the resampling back to to Mitchell Netrali (or something like that) Which he had previously used .. he thought it was down to a recent Pi update .. Dave

Very nicely done Richard.... StarNet's a great tool Dave

The Crescent Nebula NGC6888 in Cygnus. This image combines data acquired in 2018 with my Esprit 150/ASI1600mm with some recent wider field data from my Esprit150/SX-46 and piggybacked Esprit100/ASI1600m. In total 9hrs Ha, 7hrs Oiii and 30mins each RGB for the stars. Processed in Pixinsight and Photoshop with starless narrowband images made using StarNet module in Pixinsight. The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth. It was discovered by William Herschel in 1792. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energising the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures. (Source Wikipedia) Also visible at the lower middle-right is the Soap Bubble Nebula which was discovered by amateur astronomer Dave Jurasevich using an Astro-Physics 160 mm refractor telescope with which he imaged the nebula on June 19, 2007 and on July 6, 2008 (Source Wikipedia) Thanks for looking c and c welcome Dave

Interesting.. what length delay do you find works? Thanks Dave

Yep you'll pay VAT plus £12 handling charge. So £811.. Dave

That's lovely Martin.. very nicely done and you've given me an idea! Dave

All looks very neat, especially the plumbing ! and just noticed the drainage channel, very clever.. Angle grinder?

Great books Olly, very informative and I enjoyed reading your copies 😊.. I’ll put them on the Xmas list Dave

As Filroden says with this camera use matched darks and flat darks to calibrate and disable dark scaling. Bias on the ASI1600 is unstable which is why it’s best not to use it.

Oiii wavelength lies at the overlap between the green and blue filters, hence it showing in both.. Dave

Congratulations, all that hard work has paid off and your M33 looks very promising.. tricky on that size chip as it fills it. if I remember correctly sensor 90deg gets it on the diagonal which is convenient for the flip. Dave

Lovely wide field capture of the area and in less than 3hrs! What f stop are you using? Dave

Very nice David, particularly like the colours especially the blue Dave

Indeed they are Steve.. I keep my finder scope handy to quickly put on and sync manually through CdeC, can be quicker than a blind solve if its way out. A couple of weeks ago my guide star was fading away slowly.. went out to see that the scope was dewing up .. very odd I thought as dew control was on.. the next morning discovered that I'd inadvertently switched the power supply to variable and it was only putting out 8 volts.. the good news was that the Mesu and autofocus still worked and the Esprit 100 was clear! Dave