Dragon_Astro

On 12/04/2020 at 20:04, Martin Meredith said:

Arp 104 is a great place to start this thread. Yes, I can see a hint of the bridge in your shot.

I managed to capture the bridge a few years back but only with a lot of stretching... (and 12.5 minutes of exposure). Mike, perhaps you need to go longer than 5s with a CCD due to read noise?

There appears to be some kind of z-shaped galaxy cluster to the R too but I it isn't an Abell cluster as far as I can see.

Here's a nice paper describing Arp 104 https://arxiv.org/abs/1009.0219v1 with some great photos from the 0.9m and 3.5m scopes at Kitt Peak, Arizona.

A little fact about ARP 104, is that it’s also known as Keenan’s System, after Philip C. Keenan who first wrote a paper about the bridge in the 1935 😊.

Gave this a quick look last night, wow talk about needle in a haystack! 😄

Thanks Martin

 On the next clear night, looking like next week now, I want to revisit the area and get a few more long subs to stack.

I’ve been wondering what magnitude some of the objects are in this field?

4 hours ago, ScouseSpaceCadet said:

One telescope just isn't enough... From RVO, a new unused customer return Skymax 102 for a third cheaper. Accompanied by a dew shield (Yes I know they're easy to make for buttons, but I couldn"t be bothered...).

 

Aah so you bought it 😄

I wondered where it’d gone, that 127 is still there 😏🤔🤔

I’m sure most of us have seen a picture of the amazing Hubble Deep Field and with the area of it being just above the Plough, it’s relatively “easy” to have a go at capturing the brighter parts of it.

I had a quick go last night, using SGP to plate solve using the co-ordinates for the HDF that I found online.

So attached is an image giving the area of the field, and my effort which I reversed into a negative for easier viewing.

1 single 5 minute sub with the SW 150P and AA 183M. 

Many stacked subs would bring out even more.

Heart & Soul Nebula, and the Double Cluster.

Canon Nifty Fifty, Altair 183M + Baader 7nm filter.

Roughly 5mins of 15s subs live stacked and dark subtraction in SharpCap.

Quick experiment last night with the Canon Nifty Fifty lens attached to the Altair 183m Hypercam + Baader 7nm filter.

Roughly 5mins worth of 15s subs live stacked in SharpCap.

22 minutes ago, Stu said:

It did have its challenges! Phi Aquarii was right on the limit of naked eye visibility so I had to do a kind of naked eye star hop to find it as in this map. I then got the finder on it and it was very obvious then even at low power.

Using the finder got confusing because obviously everything is upside down and low power as it is, there was just too many stars to get on target.

Had a clearish spell between 1-2am but still couldn’t find it 🙈

Was tired, and my star hopping skills aren’t the best. Clear forecast tonight, so might try again when the imaging set up is fully out.

About an hour ago MO said it was clear for 1am....now it’s changed to cloudy with rain 😩

Very nice with the colour boosted a bit 👍🏻

Gin huh? Which one are you drinking? 😁

http://fdsa-blog.blogspot.com/2013/08/extragalactic-objects-in-triangulum.html?m=1

And IC 132 & IC 133 😊

You also captured the mag15 globular cluster C39 👍🏻

Just found them on Wiki....

The biggest, brightest one in the top pic I think is Ngc588, discovered in 1861.

Really good! Even still as a WIP 😊

Ive just started collecting data for m33, it really does require long subs doesn’t it? Surface brightness is that low.

It sure looks like O3, will have to check if it’s there on my CduC 🤔

Very nice!

Did you have to use a flattener when using the dslr with your WO 66?

I’ve got a SW Equinox 66, wondering how well it would work with my 450D 🤔

24 minutes ago, Stub Mandrel said:

Did wonder about one of those.

Yeah it’s not bad, mines the first version, they do another one with 4gb memory buffer.

I never use it as full size capture, the subs end up at 40mb each.

As I said, the Cocoon above is with 15s subs, only 28 of them....so that’s only 7.5mins collectively 😄

If you collected 6+ hrs of longer subs....you’d be onto a winner.

I hop about from one DSO to another, so not really hit it’s full potential at all. Must get into better habits 😁

I have an Altair 183, just a fan with no set cooling, admittedly yes the star burst is/was there. Found it very frustrating at first but correct darks get rid of it totally....100%

Heres a recent capture from the past couple of nights, I know it needs more data to smooth it out but shows what can be done with just 15s subs, mono cam, so it’s LRGB.

My guiding wasn’t set up because I was cloud dodging 😄, so subs would’ve been longer.

S.Wales doesn’t look hopeful tonight, the rest of the UK looks good though.

Early night for me I think.

14 minutes ago, Martin Meredith said:

I haven't used it so you may be right, but it is more fun trying to spot it 'manually' 😉

Very true 😏

A few subs over a few nights, then using AstroArts flicker function should help spot any movement.

17 minutes ago, Martin Meredith said:

Hi Geoff

I seem to recall capturing Pluto in a 1s exposure with a sensitive mono camera (large pixels) on a 8" f4 scope. I don't recall what the skies were like but probably in the range SQM 19.5 to 20.5. With skies of SQM 20 and a target of mag 14 I estimate an SNR of around 28, which makes it easily detectable. As others have said, the combination of a slower scope, less sensitive sensor and brighter skies will knock you back. Even so, I'm going to stick my neck out and bet that it *is* possible for you to detect it in under 5 seconds with your kit and skies. Mag 14 is quite bright for a point source.

It is worth making a test shot of any known star field (e.g. an open cluster where magnitude data is available) and estimate what magnitude stars you can detect in say 1s, 2s, 5s etc. A good object is NGC 6910 in Cygnus for this test. I've attached a single 10s sub where I estimate I can get down to mag 17-18. Doing a good stretch and inverting will help bring out the fainter stars.

Finding Pluto is another issue. Taking a shot on 2 or 3 successive nights and animating is the easiest approach (except for getting 3 clear nights in a row!).

cheers

Martin

 

NGC 6910

 

Would submitting a sub to Astrometry not automatically annotate Pluto, or does it not include planetary orbits?

As said, could just need the autostretch to be applied?

As for Sharpcap and doing longer subs, you need to tick the LX (long exposure) box next to the gain slider. Then you’d be able to do subs of 5, 10 mins+.

Or could be that your gain just  needs raising, yours could be too low if others are using 200 with the same camera.

I was out for a bit last night, but cloud and mist rolled in alot  earlier than forecasted.

Plate solve in sgp wasn’t playing ball, which was unusual because it’s been pretty reliable up till now.

Managed an hour live stack imaging in Sharpcap, trying out the new dither function, which worked well straight away.

Yup I gave up too after only managing to capture 6 subs on the Elephants Trunk.

Forecast was “clear” all night and it was even mentioned on the news that it was going to be great for UK astronomers.

Like you did, I used the cloud time to fiddle with things. PhD settings and nail polar alignment a bit better for me.

2 hours ago, symmetal said:

I checked out Sharpcap and it is intended for video imaging for planets, moon etc. using many short exposures and is not really suitable for long exposure imaging. Dithering isn't used for planetary imaging so wouldn't be a feature. The default file capture format is AVI (a video format) means its intended use is planetary imaging. It has a very good polar alignment tool, useful for setting up your mount for long exposure imaging, but good polar alignment isn't a requirement for video imaging. Sharpcap doesn't support camera cooling either on first glance, as for planetary imaging that isn't important. Taking a thousand extra video frames to stack would remove the extra noise due to not being cooled.

I would just use Sharpcap for polar alignment if you wish, and then use APT for your long exposure imaging as you're familar with that from your DSLR imaging, and there's really little difference between DSLR and astro camera imaging in that respect. You have dithering available and set point cooling with APT.

Also, proper gain and offset settings can be set in the Ascom driver using APT. The gain setting in Sharpcap does correspond to the Zwo gain settings I believe, but the offset setting is called 'brightness' under Image Controls section and the numbers don't correspond to the actual Zwo offset settings, but are arbitrary values used looking at the histogram to avoid black clipping.

Alan

SharpCap can be used for long subs for deep sky work, because I do for subs lasting minutes, along with many other people. SharpCap can also be used to capture Fit file format as well as PNG.

The “offset” is the “black level” slider under the gain.

It can also capture your Light subs and apply your master Dark frame to it at the same time, it saves all your various darks in a folder. 

The latest version of SharpCap also does dithering linked with PhD2.