Imaging of astronomical objects or large regions of the sky.

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3answers
63 views

How do we get images of galaxies?

First of all a very basic question upon which my main question is based. "Are the pictures of milkyway galaxy we see on books/mags are real ? ". If they are real then my question is, how we have taken ...
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0answers
31 views

Is it possible to approximately know the wattage/luminosity of a lamp knowing distance and using a DSLR?

I'd like to know if it is possible to approximately know the wattage/luminosity of a lamp knowing distance and using a DSLR (digital single lens reflex camera) mounted on tripod. Maybe, when shooting ...
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0answers
31 views

I have a fits file. I need to find the brightest pixel?

When I use astropy.fits to read the data of the fits file, I get a numpy array of values of shape(64,32,32). I am not able to understand what does this array contain. Ofcourse they are not RGB values ...
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3answers
109 views

How do we determine the pressure at the surface of a star?

Is there any means to do so? I know there are some means to determine the surface temperature.
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0answers
27 views

Diameter of Stellar Object Using Magnification

I took a picture of Jupiter through my telescope, using an iPhone. I know the magnification of the telescope lens I used, and can Google to get the magnification of the iPhone lens (the magnification ...
4
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3answers
73 views

Raw data acquirable from amateur astrophotography

What raw data can I possibly acquire from an 8" Classical Dobsonian Telescope, and a DSLR? Could anything eye-opening to amateur astronomers be computed or calculated first-hand with such equipment? I'...
17
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1answer
1k views

Land proportions in NASA blue marble photographs

What is the explanation for the apparent size difference of North America in these two photos from NASA? Image source Image source
26
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5answers
11k views

How do we know what the Milky Way looks like?

There is no way (with the current technology) that we could send a probe outside the Milky Way in a reasonable amount of time. So, how do we know what the Milky Way looks like, and what factors do ...
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8answers
7k views

How can we take pictures of something billion of light years away?

I have had this question in my mind for a long time, I thought you guys might enlighten me easily. I am confused about some space photographs and claims like "this galaxy is 13 billions light years ...
22
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4answers
5k views

How did they take photos of Jupiter?

How did they take photos of Jupiter - I mean Jupiter is illuminated and that's a lot of light to produce. Am I missing something, and there was some sort of dark photo technology used, or was there ...
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0answers
19 views

Non-uniform lens flares [duplicate]

I assume -- and maybe wrong -- that lens flares, in photography, are caused by light getting "trapped" inside the curved lens and bouncing around (due to refraction and non-perfect total internal ...
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4answers
1k views

Why Can We See Stars In The Sky

Why is it when we look up into the night sky we can see stars. but when you see pictures taken from the ISS you don't see any stars. Why is this?
7
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1answer
265 views

What Causes the Noise Floor of Modern CCDs?

CCDs are getting pretty good these days, but all systems are subject to noise. A typical value for a CCD seems to be 20 electrons RMS per pixel. This article from qsimaging.com says CCD Read ...
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2answers
2k views

Aligning images of starfields

I have two images taken within 30 minutes of each other in the same part of the sky. They are very similar but are slightly offset due to the Earth's rotation and other factors. I know: the X, Y ...
8
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2answers
291 views

Why do astronomers never put a scale on their photographs?

Why do astronomers never put a scale on their photographs? I have been looking at images of the Bird nebula, a collision of three galaxies, but in none of the dozen or so that I have found, nor in the ...
3
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1answer
120 views

If the observable universe keeps expanding would we eventualy see light 24/7… clouds permiting? [duplicate]

If we can see more observable universe could there be a time when day and night looked the same?
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1answer
47 views

Does an uneven and/or moving surface affect quality when using a solar filter?

I have chosen to make my own solar filter using Baader as opposed to Mylar or anything else based on these: http://physics.stackexchange.com/a/25204/6805 and http://irwincur.tripod.com/...
6
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1answer
189 views

What sort of equipment would I need to take a photo like this?

I'm interested in doing some astrophotography and I'm looking into the equipment needed to get a photo like this: http://www.flickr.com/photos/cscunha1984/6619321531/in/faves-heyvian/ I'm not looking ...
3
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3answers
217 views

Quality loss when adding more components to a telescope?

I would think this would be inherently true, but I'm curious: (Assuming the highest quality amateur instruments are used.) Is quality lost when, say, adding a T-mount adapter, diagonal or any other ...
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2answers
5k views

Celestron NexStar 6 SE vs. Orion XT8 [closed]

I'm interested in purchasing a new telescope and have narrowed it down to the NexStar 6 SE vs. the Orion XT8. I'd like to be able to get into astrophotography and read that having the Go-To (auto-...
5
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3answers
99 views

How to get started in Astronomy (UK based) [closed]

I have always been interested in space and astronomy (in my youth - I wanted to be an astronaut). However for various reasons, I never quite got started. I now want to get started - small but ...
17
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5answers
36k views

Can the “Milky Way” galaxy be seen by the naked eye in a clear sky?

Is this photo "real"? Are the stars not super-imposed in the image?
21
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5answers
3k views

What do the colors in false color images represent?

Every kid who first looks into a telescope is shocked to see that everything's black and white. The pretty colors, like those in this picture of the Sleeping Beauty Galaxy (M64), are missing: The ...
7
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1answer
107 views

When taking a sequence of exposures for stacking/coaddition, what dither patterns are most commonly desired? Why?

When taking a sequence of exposures for stacking/coaddition, what dither patterns are most commonly desired? When visiting a telescope, what default dither patterns would a visiting astronomer like to ...
13
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5answers
5k views

Where can I find public domain astronomical pictures?

Where can I find public domain astronomical pictures of nebulae, stars, etc. that can be freely used?