Can anyone platesolve this?

[lukebl]

Folks, This is a capture of part of the sky using a RunCan Night Astro camera. A very basic low-res CMOS camera, hence the poor quality, but very sensitive and used for recording asteroid occultations.

It's part of a sequence captured this morning to record the occultation of a star in Orion by the asteroid Aquitania. I basically slewed the scope to the relevant corordinates of the star (J2000: RA 06h 05m 53.6s, Dec +09° 19' 57.3"), and captured a movie of about 60 seconds around the time of the occultation. However, the starfield doesn't seem to match anything in my Carte du Ciel at those coordinates, and Astrometry.net can't platesolve it.

Can any of you clever folks manage to platesolve it for me?

This is the basic stacked image with the GPS timestamp:

Here it is edited with the timestamp photoshopped out:

[davew]

http://nova.astrometry.net/upload

Quite simple really. Give it a go,

Dave

[geoflewis]

8 minutes ago, davew said:

http://nova.astrometry.net/upload

Quite simple really. Give it a go,

Dave

Hi Dave,

Luke said that Astrometryt.net wouldn't solve it in his original post. I tried it and it failed for me too - now trying advanced settings with expected coordinates, but it's not looking promising (UPDATE - it failed again...!!). I no longer have Astrotortilla or I'd try that and PS2 needs very accurate coordinates, so that's probably not going to work either.

Luke, what is the image scale, e.g. degrees radius?

Geof

Edited September 5, 2019 by geoflewis
Update

[davew]

2 minutes ago, geoflewis said:

Luke said that Astrometryt.net wouldn't solve it in his original post

OMG ! That's frightening. I didn't even register that ! Either word blindness or stupidity

I imagine the view is incorrect anyway because of the cloning,

Dave.

[lukebl]

2 hours ago, geoflewis said:

Luke, what is the image scale, e.g. degrees radius?

Unfortuantely, I'm not sure!

I understand that the sensor is 1/1.8" CMOS (i.e. 7.18 x 5.32mm) and it was captured on a telescope with a 1624 mm focal length. I used a 0.5x rocal reducer, but I don't know the actual resultant effective focal length as I guess that's dependent on the distance between the sensor and the reducer.

[geoflewis]

1 hour ago, lukebl said:

Unfortuantely, I'm not sure!

Ok Luke, no worries.

I tried a couple of things in astrometry.net advanced settings, but as you reported it doesn't want to play, so I'm not sure that I can help further, sorry....

Geof

[JamesF]

I wonder if the noise in the image is creating false positives for stars that are subsequently messing up the plate solving?

Can you grab an image of a known location with the same camera and plate solve it?

James

[Paul M]

Try this

So how did he do it?

I found Aquitania in Sky Safari at the time you stated. Highlighted a nearby star in the field: HD251604. Nothing in the SkySafari field looked light your image but Sky Safari has an option download DSS images of the area of a selected object. So I got that DSS image and could immediately identify your field. I cropped the DSS image and plate solved it.

You'll see it's rotated about 45 deg counterclockwise to your image and is mostly the right side of your image.

Should get you there though.

[Paul M]

Full size:

[Paul M]

And just to help orientate, I've highlighted the same triangle of stars in each image:

[Merlin66]

Paul,

Well done  mate!

Great outcome.....

[lukebl]

10 hours ago, Paul M said:

Try this

 

So how did he do it?

I found Aquitania in Sky Safari at the time you stated. Highlighted a nearby star in the field: HD251604. Nothing in the SkySafari field looked light your image but Sky Safari has an option download DSS images of the area of a selected object. So I got that DSS image and could immediately identify your field. I cropped the DSS image and plate solved it.

You'll see it's rotated about 45 deg counterclockwise to your image and is mostly the right side of your image.

Should get you there though.

Great stuff and thank you!

I actually tried to solve it in a similar way in Carte du Ciel, by downloading the DSS image, but just couldn't find a match with my image amongst the mass of stars in the downloaded image. Not knowing the field of view was a big problem. I can work that one out now.

[geoflewis]

Excellent solution Paul, thanks for the lesson - definitely one for the astro toolkit

Geof

[lukebl]

Thanks again! By superimposing the images in the correct orientation and uploading the DSS image again to Astrometry, I've now worked out that the field of view with the corrector is 29.9 x 23.9 arcmin for future reference.

I've also determined that the reducer (it's a very cheap one) considerably distorts the field, which is probably why it won't platesolve. Not a problem when you're just measuring the star blinking off and back on, though.

[Paul M]

6 hours ago, geoflewis said:

Excellent solution Paul, thanks for the lesson - definitely one for the astro toolkit

Geof

Did it look like I knew what I was doing?   That is the first time I've ever plate solved!

I really just worked it out as I went along. I'm an armchair astronomer first and foremost and love playing with planetarium software. My intention was to identify the field visually but when the DSS image option popped up I got an idea...

The first thing I got from the DSS image was an indication of the field size. After that anything seems possible!

[geoflewis]

3 minutes ago, Paul M said:

Did it look like I knew what I was doing?   That is the first time I've ever plate solved!

 

3 minutes ago, Paul M said:

when the DSS image option popped up I got an idea...

Necessity is the mother of invention....!! 👌