Search found 1327 matches
- Sun Apr 26, 2020 5:12 pm
- Forum: Deep Sky Imaging
- Topic: Recreating Edwin Hubble's discovery of a Variable Star in the Andromeda Galaxy
- Replies: 4
- Views: 1601
Recreating Edwin Hubble's discovery of a Variable Star in the Andromeda Galaxy
On October 6, 1923 renowned astronomer Edwin Hubble discovered a pulsating star in the Andromeda Galaxy which quickly led to the revolutionary discovery that M31 is a galaxy unto itself 2.5 million light-years away, and not a gaseous cloud of stars within our own Milky Way. I dipped into my archive ...
- Sun Apr 26, 2020 2:24 pm
- Forum: Live Stacking
- Topic: Dark universe swamped by colured pixels
- Replies: 13
- Views: 4525
Re: Dark universe swamped by colured pixels
Like Dave I too started with the ASI120MC. I've attached a single 120-second light frame of M33 Triangulum Galaxy so you can see how the sensor was swamped by hot pixels. This camera is not designed for Deep Sky. It's best for Lunar, Planetary, and for guiding. You can still get decent Deep Sky imag...
- Sun Apr 26, 2020 1:08 pm
- Forum: Deep Sky Imaging
- Topic: Eclipsing Binary Star System: GK Boo
- Replies: 5
- Views: 1724
Re: Eclipsing Binary Star System: GK Boo
Today's NASA Astronomy Picture of the Day (APOD) is a celebration of the 100th anniversary of astronomy's Great Debate held at New York's Museum of Natural History between Harlow Shapley and Heber Curtis. Shapley argued that the Milky Way was the size of the known universe and that the Andromeda Neb...
- Sun Apr 26, 2020 12:17 pm
- Forum: Polar Alignment
- Topic: Polar aligning from ANY part of the sky
- Replies: 14
- Views: 14106
Re: Polar aligning from ANY part of the sky
This has got me thinking...
Let's suppose I was able to actively guide in both RA and DEC. If my polar alignment is off by 1 degree can I still get decent astrophotos using guiding software like PHD2? In other words, how critical is PA when you can guide?
Brian
Let's suppose I was able to actively guide in both RA and DEC. If my polar alignment is off by 1 degree can I still get decent astrophotos using guiding software like PHD2? In other words, how critical is PA when you can guide?
Brian
- Sat Apr 25, 2020 10:41 pm
- Forum: Polar Alignment
- Topic: Polar aligning from ANY part of the sky
- Replies: 14
- Views: 14106
Re: Polar aligning from ANY part of the sky
I visited the website. Accuracy within 30 arc-seconds is not good enough for me. I can only speak for myself and one other person but we do not actively guide. We rely on the accuracy of our polar alignment and periodic error correction. My mount is 50 years old. I have no control over the declinati...
- Sat Apr 25, 2020 9:35 pm
- Forum: Deep Sky Imaging
- Topic: Eclipsing Binary Star System: GK Boo
- Replies: 5
- Views: 1724
Re: Eclipsing Binary Star System: GK Boo
Thanks everyone for your encouragement. I was hoping to capture more data last night but the forecast fell apart as time approached. In the meantime I wanted to briefly discuss the differences between the two applications I used in my original post: 1. AstroImageJ, aka AIJ, allows me process my raw ...
- Fri Apr 24, 2020 4:16 pm
- Forum: Deep Sky Imaging
- Topic: Noise Reduction in Deep Sky Images
- Replies: 12
- Views: 3677
Re: Noise Reduction in Deep Sky Images
Dave, Great write up! I like your "compare and contrast" style. I too have found noise-reduction to be woefully inadequate. I use GIMP's "selective Gaussian blur" followed by sharpening, not the other way around. I downloaded Neat a few months ago. My impression was that it did a...
- Fri Apr 24, 2020 3:03 am
- Forum: Deep Sky Imaging
- Topic: Eclipsing Binary Star System: GK Boo
- Replies: 5
- Views: 1724
Eclipsing Binary Star System: GK Boo
Photometry with your CMOS or CCD camera has always been and continues to be of great importance to science. There are many different types of variable stars. There are Cepheid type stars that lie in the Instability Strip of stellar evolution that are used to measure the distance to galaxies, and the...
- Fri Apr 24, 2020 2:02 am
- Forum: Deep Sky Imaging
- Topic: NGC 5394/5395 will challenge you
- Replies: 4
- Views: 1564
NGC 5394/5395 will challenge you
One month ago I came across this "NASA APOD" image: https://apod.nasa.gov/apod/ap200304.html I looked it up in planetarium software (C2A) and saw that it was a mere 2 arc-minutes in size. That's quite a challenge for my 418mm refractor but hey I'm a glutton for punishment. I decided to use...
- Wed Apr 22, 2020 9:53 am
- Forum: How do I?
- Topic: Polar Align is good but something not right.
- Replies: 7
- Views: 1855
Re: Polar Align is good but something not right.
Yes, you are right I suppose. From your description it is hard to quantify "veering left".