Photos of the our milky way galaxy

Click For Summary

Discussion Overview

The discussion revolves around the methods used to capture images of the Milky Way galaxy and other galaxies, focusing on the techniques employed by telescopes and the challenges of observing from within our galaxy. Participants explore the differences between artistic representations and actual photographs, as well as the implications of exposure time in astrophotography.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant notes that images of the Milky Way typically show only a portion of its arms, suggesting that many representations are artistic renditions rather than actual photographs.
  • Another participant explains that capturing images of hundreds of galaxies involves pointing a telescope at a specific area of the sky for extended periods, although the exact duration is uncertain.
  • A participant describes the visual experience of the Milky Way from a dark site, emphasizing that it appears as a wide band of stars, which photographs can enhance by revealing thousands more stars.
  • One contributor shares their experience with the Hubble Deep Field observations, detailing the process of taking multiple exposures over a significant time frame to capture faint galaxies.
  • Another participant seeks clarification on the meaning of "long long time" in the context of telescope exposure and questions the significance of the number of orbits around the Earth during the observations.
  • A later reply provides specifics about the Hubble Deep Field's exposure time and the technical aspects of the cameras used, noting that ground-based telescopes have limitations compared to space telescopes.

Areas of Agreement / Disagreement

Participants generally agree on the basic methods of capturing images of galaxies, but there is some uncertainty regarding the specifics of exposure times and the capabilities of different types of telescopes. The discussion includes competing views on the visibility of the Milky Way and the nature of astronomical images.

Contextual Notes

Limitations include the dependence on definitions of what constitutes an image of the Milky Way, the challenges of observing from within the galaxy, and the unresolved details regarding the exact exposure times and techniques used by different telescopes.

Who May Find This Useful

Individuals interested in astronomy, astrophotography, and the technical aspects of telescope operations may find this discussion informative.

yalgaar
Messages
15
Reaction score
0
I have seen several photos of the our milky way galaxy, other galaxies and some photos of even 100's of galaxies in the same picture.

How do they do it? Usually if you see in the sky, all you see is the stars. (naked eyes)
I believe to be able to see actual of our milky way galaxy we need to be very very far from it; but we are part of it. How can we see it even with the best telescopes?

I have read there are highly sophisticated telescopes that watches the space for quite a long time to get a picture of 100s of galaxies but would like some detailes explanation on how is it done?
 
Astronomy news on Phys.org


You have never seen a picture of any more then a portion of a arm of our galaxy. That is all we can see, any images of OUR galaxy that you have seen must be an artists rendition.

Other galaxies are easy, just point a large telescope at the sky and let it soak up light for a while. How long a while, I am not sure.
 


You can't see the whole of our galaxy because we are in it .
You can see part of the galaxy (from us to the centre) - on a dark site in the south it looks like a wide band of stars, like a cloud across the sky.
Photographs can show up many 1000s more stars and so make it look more solid.
 


Exactly like Integral said, to get images of 100's of galaxies you just point your telescope at one part of the sky for a long long time.

One of my professors in astronomy was involved in the Hubble Deep Field observations, which basically consisted of taking the HST and pointing it at one patch in the sky for about 150 orbits around the earth. The result is this:
http://upload.wikimedia.org/wikipedia/commons/5/5f/HubbleDeepField.800px.jpg

It doesn't really take a sophisticated telescope, just a lot of patience :)
 


Nabeshin said:
Exactly like Integral said, to get images of 100's of galaxies you just point your telescope at one part of the sky for a long long time.

One of my professors in astronomy was involved in the Hubble Deep Field observations, which basically consisted of taking the HST and pointing it at one patch in the sky for about 150 orbits around the earth. The result is this:
http://upload.wikimedia.org/wikipedia/commons/5/5f/HubbleDeepField.800px.jpg

It doesn't really take a sophisticated telescope, just a lot of patience :)

Thanks for all your answers. This picture is really cool. Could you please explain what does it mean by "long long time" I am sorry I really don't know much about telescopes. I believe when you look at a telescope you see stuff. What difference it makes if you see it for longer time?

Also what does it mean by "150 orbits around the earth"?
 


The Hubble deep field (the above image) is about 30-40 hour exposure in each of 4 colours.
Scientific cameras are black+white with a filter to select the colour.

The telescope (HST) is in space and it took about 10days to make all the exposures, during which the telescope orbited the Earth 150 times.
Ground based telescopes are larger and in some colours can see fainter object (although with less sharpness) but they can't observe the same point for 40hours at a time - dawn gets in the way!
 

Similar threads

  • · Replies 31 ·
2
Replies
31
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 29 ·
Replies
29
Views
9K
  • · Replies 25 ·
Replies
25
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K