NGC55 17.5 hours

[Nicola (Nicola)]

Beautiful! I wish I could get such images...

[LucasB (Lucas)]

What a beautiful image Paul, especially for a faint galaxy like NGC55. Love the rich colour! Apparently there is a fix for the diffraction spikes for the 8300 microlens chips. I have been informed by a fellow IIS member that if you download CCDOps Version 5 from SBIG and go to Fix ME spikes in the menu it can remove them. Haven't tried it myself but if you want to have a crack let me know how it goes. Works on fits files.

Lucas

[Shiraz (Ray)]

excellent image Paul. The bulge is particularly interesting and clearly defined.

[madbadgalaxyman (Robert)]

Originally Posted by Paul Haese

Thanks Robert for your considered comments. I found one or two images out there in cyber land that sort of hinted at the spiral structure. Some of the commentary suggested it might be a barred spiral, that is caused by a night of high cloud in the mix.

Yes, NGC55 sure looks more regular in deeper exposures. Not surprising, as it is actually a regularly rotating disk structure (as shown by the rotation velocities of its neutral atomic hydrogen gas).

Low luminosity spiral galaxies are not "pretty things" because they are invariably somewhat chaotic in their structure (rarely do they have very well-defined spiral arms). However, much of this irregularity is confined to the distribution of luminous young stars.
[[ maybe M33 is only "pretty" (= strongly two-armed) because of an interaction with M31 ?!? ]]

Here is the GALEX image (downloaded from GalexView interface), which was made from two filters: the Far Ultraviolet band plus the Near Ultraviolet band.



The older stars are seen in the NUV band, which is displayed as yellow. The recently formed luminous O and B stars are extremely prominent in the FUV band, which is displayed as blue.
(even a small amount of current star formation causes the galex FUV band to detect a lot of light)

Any spiral arms that are currently forming stars will "light up like a floodlight" in the galex FUV band. Older spiral arms won't.

Sometimes, I resort to a bit of defocussing of an image to try to get a handle on the main structures in less regular galaxies like this one. Better still, go to 800 nanometers and longer in the wavelength of observation, so as to get rid of the chaotic dusting of superluminous stars.

Here is a really fun comparison, the galaxy NGC 247 as seen by Galex:



My morphological notes (from multi wavelength images) for NGC 247 say "probably one-armed, possibly barred", which is very typical for a lot of low-luminosity spirals.

[strongmanmike (Michael)]

Nice work Paul, some nice colour variation in what is a pretty boring galaxy really, so well done 17.5hrs?..really? Hmmm?...not sure I would have persevered that long.. even with 4"

Mike

[astronobob (Bob)]

Hi Paul, That an awesome image, plenty deep for a galaxy which gives it a real appealing Glow. fantastic !
And yeah, i can imagine you saying that the scope was looking like a straw
Real nice image Paul.

[Ross G]

Beautiful colour and detail.

A great galaxy photo Paul.


Ross.

[Paul Haese]

Thanks guys,

Mike I am following Martin's advice and even still don't have enough time. His advice to me last year was go 20-30 hours minimum. I have found with 20 hours of data the processing tends to be a lot easier and allows so much more stretching. You are lucky with the diameter you have and the field of view, plus the extra cooling. It would be nice to have that, but not within current budget.

Thanks for that extra info Robert. Appreciated.

[DJT (David)]

That's a great image, Paul. Love the processing etc.

Thanks

[stevous67 (Steve M)]

17.5 hours. I'm jealous. Good job Paul, very nice result.

Steve

for clear skies this new moon!

[Paul Haese]

Thanks guys. Automation is king when it comes to data gathering. Lovely nights sleep last night while the scope collected data on two objects I am working on. That's how you get 17.5 hours Steve.

[strongmanmike (Michael)]

Originally Posted by Paul Haese

Thanks guys. Automation is king when it comes to data gathering. Lovely nights sleep last night while the scope collected data on two objects I am working on. That's how you get 17.5 hours Steve.

Yeeees....wooould be nice

Mike

[Paul Haese]

Originally Posted by strongmanmike

Yeeees....wooould be nice

Mike

It could be yours too Mike. You just have to give up the NJP and automate your dome. Not much to do.

[strongmanmike (Michael)]

Originally Posted by Paul Haese

It could be yours too Mike. You just have to give up the NJP and automate your dome. Not much to do.

Not much to do???? Hmmm? firstly, ya got a higher paying job for me

Would be good...would be good.....

[Paul Haese]

Yeah I hear their hiring in the labour party. Sell that old tired NJP and get something with a home position and you will be set.

[strongmanmike (Michael)]

Originally Posted by Paul Haese

Yeah I hear their hiring in the labour party.

Hey I would be interested in doing that actually, just too many more experienced people want to fight the good fight good luck to them

Sell that old tired NJP and get something with a home position and you will be set.

One day.....

[Bassnut (Fred)]

Originally Posted by strongmanmike

just too many more experienced people want to fight the good fight

"good fight", no, thats wrong, but the "fight", thats true, give you that.

[Bassnut (Fred)]

Top work Paul, well done.

[naskies (Dave)]

Originally Posted by strongmanmike

Not much to do???? Hmmm? firstly, ya got a higher paying job for me

Would be good...would be good.....

You should create an Australian Astrophotography Enthusiasts Party and become a senator... I hear the pay's pretty good

[Rex]

Beautiful rendition Paul, the most colourful I have ever seen of this galaxy.