Time-Lapse of Comet Catalina (C/2013 US10)

[Davide Simonetti]

A very short time-lapse of Comet Catalina (C/2013 US10) passing through Ursa Major on the morning of January 20th 2016.

https://www.flickr.com/photos/davidesimonetti/24503982965/in/datetaken/

24x60 second exposures 

at 3200 ISO - one shot 

taken every two minutes.

Captured with digiCamControl

Guided with PHD

Processed in Photoshop and compiled in Virtual Dub and Windows Movie Maker

[Davey-T]

Very nice animation.

Dave

[laudropb]

Very nice time lapse. Gives a real idea of the comets motion.

[goose35]

Imaged catalina last night i have to have a bash at timelapse with my subs thats a great vid

[Davide Simonetti]

Imaged catalina last night i have to have a bash at timelapse with my subs thats a great vid

That's one of the nice things about imaging comets...you can use the same data in different ways 

[Pete Presland]

Its amazing how quick its moving.

[Paul73]

Great sequence. Any idea of the total distance moved in that time (km / arc ")?

Paul

[PhotoGav]

Excellent! Did you shoot that in London?

[happy-kat]

That's cool

[Davide Simonetti]

Great sequence. Any idea of the total distance moved in that time (km / arc ")?

Paul

I'm afraid I'm not sure how to work that out Paul. Originally I was just shooting frames to stack for a single image and then I realised I had enough for an animated sequence. The comet was really moving fast though - so fast in fact that the Ra/Dec was changing significantly as I put the info into the scope handset.

[Davide Simonetti]

Excellent! Did you shoot that in London?

Yup, this was shot from North London (Haringey area) on an unusually clear night 

[Davide Simonetti]

Its amazing how quick its moving.

That comet was really shifting! It was difficult to enter the co-ordinates into the handset because the Ra/Dec was changing so fast. I would have gone for even more frames to give a better idea of where it was and where it was heading but the guiding went a bit squiffy and mucked up the timing so I stopped after 24 frames.

[PhotoGav]

How fast is the comet moving...? From observations over three hours at the telescope in Marlborough, my colleague estimates that it is travelling across our field of view at about 7km/s. That doesn't take into account its movement away from us.

[Davide Simonetti]

How fast is the comet moving...? From observations over three hours at the telescope in Marlborough, my colleague estimates that it is travelling across our field of view at about 7km/s. That doesn't take into account its movement away from us.

I'm not knowledgeable enough to  be able to work out the comet's speed but just from observing it was evident that it's moving really fast. To image it I had to keep exposures to no more than a minute to avoid it streaking which meant using a high ISO. I'm not sure if it's moving faster than other comets I've imaged because this is the first time I've used guiding when capturing one of these objects (I was hoping I'd be able to get away with longer exposures to try and capture it's tails but that wasn't to be). On previous comets I was restricted to 30 second exposures at the most.

[orion25]

Wow! That's amazing! I've read that as of last week the comet was moving at about 132,000 mph (~212,000 kph), heading back to the Oort Cloud.

http://earthsky.org/space/comet-catalina-c2013-us10-november-december-january-2015-2016

Your animation really shows Catalina on the move!

Great job!

Reggie

[calli]

Nice one.

 

Can you please share some informations about the wedge and your guiding technic?

 

Cheers.

Carsten

[Davide Simonetti]

On 1/24/2016 at 21:45, calli said:

Nice one.

 

Can you please share some informations about the wedge and your guiding technic?

 

Cheers.

Carsten

Hi Carsten,

The wedge is a simple homemade thing made of wood which is fixed to the tripod. It is designed so that the camera doesn't bash into the tripod when slewing. The alt-az mount sits on top of this so that where it would normally point straight up it now points at 51 degrees (so it can be aligned on Polaris for a polar alignment - I live in London) The wedge is a fixed angle so it only really works in London and the South East of the UK (sorry about the rubbish picture but it should give an idea).

For guiding I use the Orion 50mm Mini Guide Scope and my ZWO ASI 120C camera. The software I use is PHD . Obviously it's not an Ideal setup but it's the best I can afford at the moment and it works most of the time. I hope that helps 

 

[calli]

Thanks Davide,

that really helps. I have the same Telescope (and an also tight budget and willing to first get out most from what I have), however the first thing was to put it on a more sturdy tripod. I am thinking about to build me a wedge some months now, normally I print all needed parts on my 3D printer but this will not work here :-)

I am still wondering why it should not possible to guide an Alt/Az mount (in Alt/Azm Mode!). I played a bit with LinGuider on a raspberry Pi and it seems that this is one road block. On the Mount side there seems to be the problem that when the telescope tracks it will not accept delta movements. However, as soon I have a star tracked I don't care about the tracking and can use only the guider.

Carsten

[Davide Simonetti]

Wow, 3D printer...that must be a useful piece of kit  I don't think guiding will work properly in alt-az mode, however, I never tried. I was hoping that just using a wedge would give me longer exposures but the difference was negligible which is why I opted for guiding and though it can be terribly frustrating I can now get at least 8 minute exposures whereas before the most I could hope for was 30 seconds . I did experiment with turning the tracking off to see if guiding would do all the work but there is far too much movement so the only way for me is tracking in EQ mode and guiding. As soon as I can afford one, I want to get a proper EQ mount. My tripod isn't sturdy enough and there is no way to properly counterbalance all the weight on my mount.

[calli]

Yes, a 3D Printer is great if you are in CAD. I am more a maker than an engineer (I have a diploma but in biotech so not very much CAD here) and often have to "evolve" my designs. It would be VERY bad and expensive if this would be made in a normal maschine shop. I just designed the parts for a dew heater and a focusser (here a link to the topic:

), in the background you can see the printers :-)

For the guiding in Alt/Az mode, I think it can work, only maybe the solution is so uncomon nobody cares to put effort into it. I think the bigger Alt/Az mounts from Celestron and Meaede just do it fine? The other thing is the FOV rotation I guess. How is that for your 8 minutes subs?

Carsten

[Guy Wells]

Cometary animations are nice.

[Davide Simonetti]

6 hours ago, Ras Skipper said:

Cometary animations are nice.

And fun to do 

[Davide Simonetti]

9 hours ago, calli said:

Yes, a 3D Printer is great if you are in CAD. I am more a maker than an engineer (I have a diploma but in biotech so not very much CAD here) and often have to "evolve" my designs. It would be VERY bad and expensive if this would be made in a normal maschine shop. I just designed the parts for a dew heater and a focusser (here a link to the topic:

), in the background you can see the printers :-)

For the guiding in Alt/Az mode, I think it can work, only maybe the solution is so uncomon nobody cares to put effort into it. I think the bigger Alt/Az mounts from Celestron and Meaede just do it fine? The other thing is the FOV rotation I guess. How is that for your 8 minutes subs?

Carsten

The field rotation is a large part what I'm trying to avoid and with 8 minute subs it would be very noticeable. Stacked images would have to be cropped radically. I like what you've done. Your focuser looks interesting, nice design, how well does that work?

[calli]

The focuser works good. I am not 100% happy with the design, I think there is too much lateral force on the motor axle and the bearings. Maybe I need to rething the belt idea and switch to gears.

Carsten

[Davide Simonetti]

On 1/28/2016 at 11:17, calli said:

The focuser works good. I am not 100% happy with the design, I think there is too much lateral force on the motor axle and the bearings. Maybe I need to rething the belt idea and switch to gears.

Carsten

I think gears might do a better job than the belt but I admire your ingenuity