The Macclesfield Deep Sky Image

[Richard N]

EAA is pretty amazing. On the evening of the 29th. I took an image that had all of 280 seconds of integration (8 second subs). The area that I imaged was within the Persus Cluster. I then ported the image into Aladin to compared it with Panstarrs and SDSS.  The results were nothing short of amazing. Aladin uses the SIMBAD database (and others) to label objects. The image with some objects labelled is below. Further examination showed that I have captured a "Blue Straggler" and also (drum roll) a Quasar! This quasar (labelled QSO) is 11 billion light years away and heading off at 253,000 km/s - the speed of light is 300,000 km/s so it's really shifting...

Still gobsmacked.

Tech detail: 80mm refractro. AZGTi. Sharpcap. No post processing.

If you are interested in more unusual objects I do recommend learning how to use Aladin. It's a tool used by professional astronomers and requires an understanding of the merits of the numerous databases. It makes those EAA images much more interesting.

Edited December 31, 2023 by Richard N

[PeterC65]

I've also observed a Quasar via EAA, 4C+16.30, just a little dot but I was thrilled to be able to observe it at magnitude 15.7.

Something I do occasionally with EAA is to check the magnitude of the faintest star I can see, usually when observing a star cluster or just a star field. I zoom in on a promising patch and compare it with Stellarium. The faintest star I've managed to observe so far was magnitude 17.5.

 

[Richard N]

2 minutes ago, PeterC65 said:

I've also observed a Quasar via EAA, 4C+16.30, just a little dot but I was thrilled to be able to observe it at magnitude 15.7.

Something I do occasionally with EAA is to check the magnitude of the faintest star I can see, usually when observing a star cluster or just a star field. I zoom in on a promising patch and compare it with Stellarium. The faintest star I've managed to observe so far was magnitude 17.5.

 

I think that marks the difference between astrophotography and EAA. I was looking at an astrophotography image today where all the stars etc had been removed with just some nebulocity left. To me it was an evicerated view of the sky with all the interesting stuff removed. I’m planning on taking a good look at M31 sometime soon. But not to get a pretty picture, rather to look at some of the interesting objects within and around it. I suspect some get processed out in astrophotography images. 

[John]

There are some quasars bright enough to observe without electronic assistance. I've seen the brightest, 3C 273, with my 100mm refractor and several more with larger apertures.

 

[Richard N]

Incidentally I would strongly recommend using Aladin for examining EAA images. It’s a free tool used by professional astronomers. It does require some knowledge of the various surveys available to get the best out of it. I put my images in and sync them to a deep sky survey such as Panstarrs or SDSS. I then overlay data from Sinbad or Neds. It’s then straightforward to identify faint objects. You can then drill down to get all sorts of astrometric data and papers related to the objects. Took me a couple of hours to use it effectively. Time well spent. 

[Richard N]

7 minutes ago, John said:

There are some quasars bright enough to observe without electronic assistance. I've seen the brightest, 3C 273, with my 100mm refractor and several more with larger apertures.

 

Definitely! But not from my light polluted location. Most of them are mag 16 or fainter. 

[PeterC65]

26 minutes ago, John said:

There are some quasars bright enough to observe without electronic assistance. I've seen the brightest, 3C 273, with my 100mm refractor and several more with larger apertures.

 

I've added this one to my list of things to observe. Thanks.

[PeterC65]

22 minutes ago, Richard N said:

Incidentally I would strongly recommend using Aladin for examining EAA images. It’s a free tool used by professional astronomers. It does require some knowledge of the various surveys available to get the best out of it. I put my images in and sync them to a deep sky survey such as Panstarrs or SDSS. I then overlay data from Sinbad or Neds. It’s then straightforward to identify faint objects. You can then drill down to get all sorts of astrometric data and papers related to the objects. Took me a couple of hours to use it effectively. Time well spent. 

I will give Aladin a try.

[Fir Chlis]

On 31/12/2023 at 10:47, Richard N said:

Incidentally I would strongly recommend using Aladin for examining EAA images. It’s a free tool used by professional astronomers. It does require some knowledge of the various surveys available to get the best out of it. I put my images in and sync them to a deep sky survey such as Panstarrs or SDSS. I then overlay data from Sinbad or Neds. It’s then straightforward to identify faint objects. You can then drill down to get all sorts of astrometric data and papers related to the objects. Took me a couple of hours to use it effectively. Time well spent. 

 

On 31/12/2023 at 10:28, PeterC65 said:

I've also observed a Quasar via EAA, 4C+16.30, just a little dot but I was thrilled to be able to observe it at magnitude 15.7.

 

Something I do occasionally with EAA is to check the magnitude of the faintest star I can see, usually when observing a star cluster or just a star field. I zoom in on a promising patch and compare it with Stellarium. The faintest star I've managed to observe so far was magnitude 17.5.

 

I've just seen this thread, and had a look at some of my EAA images in Aladin, while waiting for the next observing session. This looks really interesting and I've had a go at checking out what is in my images.

Quite by chance, I found that my image of M77 had a quasar in it - so that's something new for me. And by comparing with Stellarium, I've found that I am seeing stars with magnitude 17.95 (and maybe dimmer), but this is the limit for Stellarium (with all the catalogs loaded) so I can't confirm if I'm seeing dimmer stars.

I've been able to get data from Simbad, when clicking on objects in my image in Aladin, but I haven't found how to get data out of NED. As you know, Simbad highlights in red, and clicking on an object will often bring up a web page, but quite a number of times it will just say that the object isn't in Simbad (unknown by Simbad). When I overlay my image with NED, there are far more objects (highlighted in blue), but when I click on them I don't get any information unless they are in Simbad.

 

Geoff

 

 

 

[PeterC65]

On 31/12/2023 at 11:10, PeterC65 said:

I will give Aladin a try.

@Richard N I've tried using Aladin twice now without much success and wondered if you could point me in the right direction?

I'm loading a FITS stack from SharpCap, the going to Image | Astronomical calculations to add the calibration via WCS. Is this the right thing to do? It doesn't get the calibration right, so when I click on an object in the image it says it isn't in Simbad. There seems to be an offset as the object marker in Simbad is located to the right of where it is in the image. Any suggestions? Can Aladin do plate solving and work this stuff out for itself? I'm finding it spectacularly unintuitive, and the manual is useless.

 

[Martin Meredith]

I've used Aladin a lot, but never for uploading/solving my own images. I simply put the relevant Aladin layer (DSS etc) side by side with my image and do a manual comparison.

What you might find useful is the custom layers function (accessed via the stack icon at the top left). This allows you to choose any catalogue you wish to overlay, by clicking on 'add catalogue' and then typing in part of the name. For instance, "milliqu" will get you the million quasars catalogue. Then click on 'load cone', which provides labels within a specified radius of the current point. You'd be amazed how many quasars there are in each field.

 

[Fir Chlis]

Since seeing in this thread about labelling /identifying, I’ve been looking at Aladin and, since I discovered it yesterday, Pretty Deep Maps.

As it was cloudy last night, I’ve now got a procedure for finding out what is in my photos, after the event.

First thing is to calibrate your own image using nova.astrometry.net/upload Processing can be temperamental – sometimes it’s quick, sometimes very slow. Load up the image, go to the results page, and wait for your result, then click on new-image.fits to download it. You always get a file called new-image.fits. I normally rename it (e.g. NGC3718.fits).

 

I then start up Aladin (desktop version) and drag and drop my image onto the Aladin Window. It usually goes in zoomed, so I zoom out (mouse wheel) until I can see the entire image.

I then click on the Panstarrs link near the top left-of-centre of the screen, which will load the Panstarrs image, obscuring mine.

By clicking on my image layer (bottom right of screen), and adjusting the Opacity slider just below there, I can gradually superimpose my image over Panstarrs.

I then click on the SIMBAD link near the top of the screen, which overlays icons over all items that SIMBAD knows about.

I'll normally zoom in now. Clicking on any of these icons and keeping the mouse there should show a small magnifying glass and a small information window will pop up, which can be clicked on for more information. You need be precise with the mouse position on a home PC – I suspect that Aladin was written for large hi-res computer screens. If there are two coincident objects, a table should appear at the bottom of the screen after clicking on the icon, You click on an entry in the table for more information.

Sometimes for the very first click in a session, things will be offset, but after that first click, this ‘feature’ seems to go away.

You can filter what is displayed by SIMBAD, but I haven't had a chance to look in detail at that aspect yet.

I hadn't found this terribly easy to navigate, but now that I have found Pretty Deep Maps and display this alongside Aladin, I can get a lot more information about my photos.

 

Geoff

[PeterC65]

@Fir Chlis, thanks, this is really helpful. I've tried following your method but using ASTAP to do the initial plate solving and that seems to work. I think the problem I was having is that the initial FITS file I was using wasn't properly plate solved. I need to spend some time now properly trying out Aladin. I'll also take a look at Pretty Deep Masks. I can't find it on Google. Can you post a link?

 

Edited March 17 by PeterC65

[Fir Chlis]

@PeterC65 It's Pretty Deep Maps, developed by @Martin Meredith, the link is in his signature - just look for his posting earlier in this thread. It's a big download, about 10Gb, and you need to unpack all of the 7 or so zip files into a single folder - and it's definitely worth reading the guide.

It's a collection of PDFs which have links to other PDFs in the collection. I found that Acrobat Reader on Windows was popping up a security warning every time I clicked on a link, but I have managed to change the security settings so that it doesn't do it any more. I'll let you know what I did if needed.

As you can't rotate Pretty Deep Maps, I rotated the coordinate system in Aladin to match.

I was using the .PNG file that was saved from a Live Stack in Sharpcap when I pressed the Save as Seen option at the end of stacking an object.

[PeterC65]

2 hours ago, Fir Chlis said:

@PeterC65 It's Pretty Deep Maps, developed by @Martin Meredith, the link is in his signature - just look for his posting earlier in this thread. It's a big download, about 10Gb, and you need to unpack all of the 7 or so zip files into a single folder - and it's definitely worth reading the guide.

OK. I do remember looking at that now. Quite a lot to download.

The issue I'm having is with plate solving my stack snapshots. These are usually PNG files so they don't have the FITS header with the starting point. The only plate solver I've found that works reliably is the one built in to SharpCap and that one won't allow saving of the FITS header as far as I can tell.