The Dumbbell Nebula (Messier 27 or NGC 6853) is a planetary nebula in the Vulpecula constellation, at a distance of about 1360 LY. Its central region contains the largest known white dwarf star.
For this image I used three 240 second exposures on Lightbuckets LB-0003 with the following filters:
Hydrogen-Alpha in Green
Sodium II in Red
Oxygen III in Blue
MaximDL was used to stack, align and screen stretch. The image was then cropped using Gimp.
Messier 99 is easily visible this time of year, situated in constellation Coma Berenices. It was one of the first objects to be identified as a spiral.
I used Lightbuckets and a standard RGB filter with a 60 second exposure for each. Imported into Maxim for stacking and screen stretching. Not as nice as I would have hoped. Maybe I just missed something in Maxim.
The Orion Nebula (Messier 42) is one of the most impressive astronomical objects to capture by CCD. Most images of it are captured using the standard RGB palette. Not to be outdone, I’ve attempted to create a stacked image using different wavelength filters, essentially mimicking what’s been dubbed the Hubble palette.
This image was taken using three 120 second exposures on Lightbuckets LB-0003 with the following filters:
- Hydrogen-Alpha in Green
- Sodium II in Red
- Oxygen III in Blue
I used MaximDL to stack, align and screen stretch. Then I used Gimp to add weight to the Red channel, which brings out all the yellows and colour details. Not bad for my first attempt using such a short exposure. MaximDL is awesome!
Given that its fall and M31 is in good position for viewing, I thought it would be worth capturing some pics. So during our last new moon, I used Lightbucket’s wide-field scope (LB-0002) to capture 30 second exposures in R/G/B x 5 each. My intent was to stack them and really show off some colour contrasts.
Its harder than it sounds. The whole exercise turned out to be a learning experience with Maxim DL. Not only is M31 way too bright to show off these colour differences with such a small image set and small exposure time, but its also a huge object! Of course I already knew this, but I figured the wide-field CCD would be big enough. Not so.
Here is a stacked image showing the core cloud and some of the spiral shadows. Beautiful, but I wanted to glean more details from my images.
So I played with DL’s histogram stretching and this is what I got. Note the “blue-ness” of the cloud is now represented and there is a lot more spiral detail (but I still could not coax any red stars to stick out more). Interestingly, the signal-to-noise ratio takes a hit (see the graininess) when you try to bring out more detail.
So today’s lesson is that when stacking images to coax out detail, you have to strike a balance between getting a clean image with little detail vs. a grainy image with too much detail.
Seeing as how the summer triangle is high in the sky now, I thought it appropriate to photograph M57, near Vega. Here is the result using as few minutes as possible on Lightbuckets. If I somehow manage to increase the astronomy fund, I’m sure this will get much clearer.
I was reading a telecope magazine the other day, drooling over the super-expensive dobs that I can’t afford when I came across an article on web-based observatories. What a cool idea. So I went to Lightbuckets to check it out. Wow! I can rent time on some really big scope in the middle of the New Mexico desert, fully automated with kick-ass CCD capabilities. All for the price of a week’s worth of overpriced coffee from Starbucks.
I just had to give it a try. So I randomly picked an unremarkable globular cluster — M53 and scheduled a session. Weather permitting, the site generates all the colour filtered, dark, bias and flat files automatically and very politely emails you when its done. I even got to sleep through the night. After pumping everything through Maxim DL to pretty it up, here’s what I got. I must say that I am very impressed. I now have my very own $30K scope. Just less coffee.