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NGC4565 - Needle Galaxy in LRGB

LRGB Collaboration
Crowd imaging projects •11 replies•116 views
In case you're *not* interested in joining, please let me know your thoughts. Here are some possible answers:
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Björn Arnold avatar
Björn Arnold avatar
Hi,

With a bit of luck, it might be that we have a rather clear night on Saturday. Since at my location, astronomical darkness is said to start at 11:11pm, taking a set of LRGB data of an object can become difficult when there's no projection when the next clear night might happen.
I think this might be a good opportunity to collect data as a group.

What I would image with is my 8" SCT, reduced to 1420mm FL and my mono camera (2.4um pixels), yielding a resolution of 0.35"/pixel (since it's CMOS, binning can be done later but even without binning, I believe the results look pleasing - please check my M81). The FOV would be 0.53x0.35 degrees.

Anybody there who would like to join?

Please share your thoughts or comments. 

Björn

Here's a star map with a possible framing (the smaller frame is the above setup, the larger frame would be my APO at f=370mm).
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Taddeuccis avatar
Taddeuccis avatar
This time i have to pass… images acquired from Bortle 8 skies would ruin all the work
Jérémie avatar
Jérémie avatar
That’s in my blind spot of the sky.... Unfortunately I can only image up to 60 degrees dec and start shooting when they are at my zenith, for ~6 hours. I put a 360degrees image of my garden in Stellarium to share my view :-)

I may propose later to group-shoot something that will be close to Polaris and require many, many hours to be visible : Ou4 nebula (squid nebula). But to avoid making people lose their time with my subs, I will try first to get a few hours from my bortle 8 sky : otherwise it is a bit like asking people to shoot if for me...

That’s too bad for the needle : I have been wanting to shoot it since I got my RC8 (asi183mm like you have), but that’s behind the neighbours building...

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Björn Arnold avatar
Björn Arnold avatar
Thanks for your feedback! The galaxy is just a proposal. I also thought about collecting more Luminance data for the M82 that I already shot under heavy moonlight to show much fainter detail. If any of you have ideas, please create a thread in the group's forum. 

@Taddeuccis I'm just wondering if that would be really the case. Of course it depends on your place how high the object's in the sky. 

@Jérémie That view of yours looks really tough! Depending on where I set up my rig in my garden, I have quite some opportunities. Usually the north eastern quadrant is completely blocked through my house. In addition, I consider everything below an alt. of 25 degree as "not observable" for my location.

As I said: it's a hobby. Join if you like and can. Open your own proposals if you have something in mind. I think with this attitude one can only gain something.

Clear skies! (and that's the major issue in the recent weeks)

Björn
Taddeuccis avatar
Taddeuccis avatar
The problem is that the object is right above Rome… so light pollution It's really a problem. Maybe i can aquire some h-alpha data… but even that is pretty bad, unless you got 50h of exposure
Daniel Erickson avatar
Daniel Erickson avatar
Jérémie:
I put a 360degrees image of my garden in Stellarium to share my view :


Those are pretty cramped quarters! I have some trees and power towers, but nothing like that... I do have the north circumpolar stuff all year though... Here's my question, though--how did you take that picture and put it into Stellarium?

Thanks!
Daniel
Daniel Erickson avatar
Daniel Erickson avatar
Björn Arnold:
Anybody there who would like to join?

Please share your thoughts or comments.


I can certainly get on target, but I'm concerned that my RedCat wouldn't contribute much to the effort...galaxies are such tiny blurs in my FOV...then there is that rain.  If you think there's even a remote chance of my data being usable, let me know and if there's a window, I'll shoot it.
Björn Arnold avatar
Björn Arnold avatar
Daniel Erickson:
I can certainly get on target, but I'm concerned that my RedCat wouldn't contribute much to the effort...galaxies are such tiny blurs in my FOV...then there is that rain.  If you think there's even a remote chance of my data being usable, let me know and if there's a window, I'll shoot it.

If I'm not mistaken you use a DSLR and an OSC with a SONY IMX183 chip? I checked the numbers for the IMX183 which would give you 2"/pixel. Usually people say that for LRGB, L can be shot in high resolution and RGB in lower res (i.e., usually through binning). Certainly the bayer matrix is effectively reducing the resolution already for the R and B. Without any practical experience for this scenario, I would still say, the data should be compatible and produce reasonable results. (in the end, the experiment decides who's right).

However, I'm just checking the weather forecast and as usual the opinion of the weather forecaster changes like the weather. It might already be clear tonight. What seems to be rather certain is that it'll be windy over the weekend which makes the SCT a welcome target for wind. My APO behaves much better under these conditions.

So, I'm open to also shoot another target this weekend using my APO and come back to the Needle another day.
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Brian Boyle avatar
Brian Boyle avatar
Hi Bjprn, I would love to have a go with my RC8/ZWO1600MM combo.  Unfortunately the Needle never get higher than 19degrees from my place at -45S and barely rises above the walls of my observatory.  I could shoot it through the open door (facing North) for an hour or so, but I suspect the image quality will not be great.  I would class my site as a "4arcsec at best" site.  I could take some colour data if you want.  How long do we have to get the data?  The rest of the dark part of the lunation doesn't look too great. 
Brian
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Jérémie avatar
Jérémie avatar
Daniel Erickson:
Jérémie:
I put a 360degrees image of my garden in Stellarium to share my view :


Those are pretty cramped quarters! I have some trees and power towers, but nothing like that... I do have the north circumpolar stuff all year though... Here's my question, though--how did you take that picture and put it into Stellarium?

Thanks!
Daniel

Hi @Daniel Erickson  !
Very easy if you already know how to make pano photos. I copy paste some links heres : but the process is (i) make your « latlong » (width = 2x height) using Photoshop or PTGui, (ii) in Photoshop with lasso tool or any other technique, determine the transparency zone for the sky (mask) and save as a PNG with the transparency layer (alpha), (iii) put that into a proper directory in the Stellarium main directory, with a little text file.

(i)
https://www.youtube.com/watch?v=nkdiqbt3Dms
or 
https://www.youtube.com/watch?v=yw5FwrZwTdc

(ii) and (iii)
https://www.skyatnightmagazine.com/advice/diy/stellarium-how-to-create-a-customised-landscape/
Daniel Erickson avatar
Daniel Erickson avatar
Jérémie:
Very easy if you already know how to make pano photos.


@Jérémie  Thanks so much! Easy to do with the right directions!
Björn Arnold avatar
Björn Arnold avatar
Brian Boyle:
Hi Bjprn, I would love to have a go with my RC8/ZWO1600MM combo.  Unfortunately the Needle never get higher than 19degrees from my place at -45S and barely rises above the walls of my observatory.  I could shoot it through the open door (facing North) for an hour or so, but I suspect the image quality will not be great.  I would class my site as a "4arcsec at best" site.  I could take some colour data if you want.  How long do we have to get the data?  The rest of the dark part of the lunation doesn't look too great. 
Brian

Hi Brian,

Thank you for your offer! Unfortunately, tonight the weather won't allow shooting anything. I took the APO outside last night for not losing the skills with my equipment. I realized that the nights became quite short now (while yours are still getting longer).

Since you're at 45S, the Needle is indeed difficult. Do you have a target that you could shoot more easily and would like to shoot but also still in my range (49N)? 
I was thinking that for projects where people are located north and south, the months of March and September (+/- 1month) could be better to find a common target as the nights have both equal lengths which gives better time frames? 

I also like to shoot more with my SCT. It took me a while to get to the point of making good (my opinion) images. The small APO is/was much easier to manage.

Cheers,
Björn
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