Questions tagged [night-sky]

Questions regarding the visible night sky during nighttime from Earth.

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4
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2answers
2k views

How can we know if a star which is visible in our night sky goes supernova?

Let's say there is a star about 3000 light-years away from earth visible in our night sky. If this star were to go supernova tomorrow(not relative to earth's night sky), we would know about it 3000 ...
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2answers
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Will Starlink deface the night sky?

There is some discussion (and there are some questions on this site) about the impact of Starlink on observational astronomy. I am not an astronomer, but I am amazed by the beauty an immensity of the ...
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What is use of Greek Letters in Astronomy? [closed]

We see letters such as $\epsilon$ or $\alpha$ or $\beta$ or $\eta$ etc... (possibly all Greek letters) Can Somebody state the use of all Greek letters in astronomy?
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How will planets behave in the night sky as seen by Mars colonists?

Certainly among the first colonists on Mars there will be a few people interested in Astronomy enough to enjoy the night sky. For them, familliar Mars will be missing and there will be a new, ...
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1answer
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What are the aspects does the moon differs between cities located on the same latitude?

What are the aspects does the moon (astronomical position and other astronomical aspects) differs between cities located in the same latitude? - For example: Seattle, Munich, Vienna, and Ulaanbaator ...
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Are the stars distributed in uniform distribution, on the celestial dome, with respect to brightness?

Has there ever been a statistical analysis of the distribution of stars in the sky (on the surface of the celestial dome), by brightness? I want to know if they are uniformly distributed. For example, ...
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3answers
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Did the night sky ever change in recorded history?

I wonder whether there has ever been a major change of the firmament in recorded history, like changes in the positions of stars, changes in constellations, or stars disappearing after going supernova....
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Density of stars on celestial sphere

The pattern of stars on the surface of the celestial sphere seems perceptually to have an universally looking structure. If you pick a region of the sky at random, for instance by using the (excellent)...
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1answer
129 views

Naked-eye limiting magnitude: mismatch between Wikipedia, online converter and Shaefer's formula

I'm trying to make sense of the difference between the reference Sky Quality Meter (SQM) readings given in the Wikipedia article on Bortle scale, online converters like [1] that are based on Shaefer's ...
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1answer
39 views

Star visibility above horizon map likewise day & light map or moonlight world map

I am looking for an option to present the given star visibility world map likewise day & night map or moonlight world map like below: Question: Is it possible to generate a map like this for some ...
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1answer
152 views

When I see Mars, I see only red light

I have a 700 mm focal and 76 mm aperture telescope. I bought it a few days ago. I tried to spot Mars for 3 days but I only see red light. I use an 20 mm eyepiece for finding it and 4 mm eyepiece for ...
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What would go into the design of a simple sky quality meter, used to measure night sky brightness?

@MCG's answer mentions several methods to classify night sky quality or brightness, and goes on to say: Additionally, you could always purchase a SQM (Sky quality meter) which is a small, portable ...
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Will the night sky ever be more stars than darkness? [duplicate]

Given enough time, will enough light from distant stars reach Earth so that our night sky will be more than 50% stars?
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1answer
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Star Map Vs Star Catalogue vs Planetarium Software

What is the difference between a star map, star catalogue and the sky provided by planetarium software? I have read the wiki but was having a hard time understanding how the data, accuracy and detail ...
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0answers
299 views

Identify moving object in the sky at night?

Last night in the Carribean, I was looking at the sky at about 8PM EST, and I noticed this really tiny object moving pretty fast from left to right, just between the two stars in the photo. It's very ...
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1answer
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How much clearer are stars in earths orbit?

As a child I remember my parents taking camping in California, and upon stepping out of the car I was awestruck at how thick the Milky Way galaxy was and at the number of stars everywhere. I've always ...
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1answer
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How do I find out when a constellation reached its zenith?

I found this website to look at the sky at the specific time and location: http://www.fourmilab.ch/cgi-bin/Yoursky - you can insert latitude and longitude and time to see how the skies looked at any ...
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1answer
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Is sky-glow affected by height?

I'm an architecture student and my graduation project will consist of building a research center for outer space, my question is whether or not height would affect sky-glow or not ? Thanks in advance, ...
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2answers
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Is there a webpage that shows the night sky but can filter out dim stars?

This webpage is very good for viewing the night sky and learning the names of the stars Timeanddate - Astronomy However, it shows too many stars. Because I live in the city, I can only see about 50 ...
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What is the average luminance of the star background?

What is the luminance of the star background, i.e. of all the objects outside of the Solar system? E.g. if we measured average luminance of the sky from the far side of the Moon (so that solar and ...
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1answer
98 views

How can I see a star behind a mountain range? Do I move apart from it and up?

Could some explain what I need to do to see a star that, from my point of view, is behind a mountain: Obviously, if it's one mountain, and not a very high one, I can just climb it to see what's ...
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3answers
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Is there any scientific correlation between cold nights and star-lit skies?

I've many times heard expressions such "cold, starry nights". It's apparently poetic to describe star-lit night skies as being "cold". Is this based on reality in some way? Is ...
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1answer
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Why doesn't the night sky keep on getting brighter and brighter every day? [duplicate]

I think this should happen because of the below logic. Consider Day 0 of planet earth. There is no light coming from any surrounding star that has reached our planet and hence its pitch dark. On Day ...
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1answer
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What inaccuracies are in this Stellarium depiction of the sky?

I found this depiction on Stellarium of the sky as seen from near the Apollo 12 landing site on January 11, 2131. The earth is the black circle in the arm of the Milky Way. Here is a similar view ...
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2answers
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Does the Sun and Moon basically appear to "move on the sky" identically regardless of location and date?

For a long time, I've been trying to use Stellarium (simulation) and many visualizations and animations in order to get a good idea of how the Sun and Moon move across the sky, as seen by a human from ...
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1answer
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Historical Lunar Tables and the Associated Error Bound

Consider as an example, AstroPixel's ``Six Millennium Catalog of Phases of the Moon''--- http://astropixels.com/ephemeris/phasescat/phasescat.html My question is two-fold: How are these tables which ...
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Can someone help me to identify this section of the night sky?

I have this image from a treasure hunt, I'm fairily certain it's a real piece of the sky, but I've been unable to identify it, can anyone help?
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0answers
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What could have this blue "bouncing" trail been? [closed]

Last night at around 8:45 PM (UK Time), I saw something I've never seen before. It was a cloudy night and I saw a flash in the sky. When I looked towards it, I saw something that looked like a ...
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2answers
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How dark/bright are polar nights?

During the polar night directly at the pole the Sun sets once and—after a period of twilight—stays down for months at a time. The only sources of non-human-made light are the stars, the auroras, and ...
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2answers
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My local night sky is so bright that I can only see the Moon, so would a low-cost telescope be any use?

Light pollution is so bad near our home that we can't see anything other the Moon in the night sky. For instance there is a street light on all night right in our lane and there are many other housing ...
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1answer
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Right ascension, Equinox, Positions Help

I am trying to answer the following question which I slightly understand but need a clearer explanation: What are the times of year to observe an object at X hours of RA at visual wavelength? I am ...
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1answer
75 views

360 degree image of the whole sky

I look for an image that I know exists. It is an image showing the whole sky, showing all stars and galaxies bright enough to be visible at the resolution, projected to the same shape that is commonly ...
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2answers
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Events I cannot explain

In the last few days I experienced two events I cannot explain. I watch the sky since I was a child so I'm aware of most events like satellites, ISS, Iridium flares, etc... First event It was about 22:...
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5answers
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Seeing comet NEOWISE?

Today the NY Times published an article that explained how to see NEOWISE at night. The article explains it like this: To catch NEOWISE yourself, look up at the northwest skies about an hour and a ...
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1answer
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Where should I be looking to see Neowise in southern Sweden?

I'm in the south of Sweden and just spent over an hour trying to find Neowise, but didn't see it. I live in a rural area, there are no lights nearby and there is a small hill with clear visibility ...
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3answers
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I'd like to photograph NEOWISE from Los Angeles, what is the optimal time?

I live in Los Angeles and have a camera adapter for my telescope -- nothing fancy just an Astromaster 114. What is the optimal time, in terms of dark sky and bright comet, to take a photo of Comet ...
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2answers
345 views

How to make a star chart from entries in a Bright Star Catalogue?

I know very little in astronomy, but I want to use the data in a Bright Star Catalogue to create star map projections for a specific time and place. For example one line is ...
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0answers
56 views

How does the Astronomical Twilight depend on the night length or the day length?

Some references say that the Astronomical Twilight starts at the last 1/8th of the night length, so it is long in Winter and short in Summer; But by using the 18 angle (sun elevation below the ...
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2answers
4k views

How to create 3D animation of particles position vs time in python?

I am trying to make a 3-D animation of stars' position vs time. I have the information of the stars' x, y and z co-ordinates over time. I was looking at the example of Matplotlib and did understood ...
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1answer
121 views

How to make projection from altitude and azimuth to screen with screen coordinate system?

Thanks to @ohoh for helped translate ra and dec into alt and az. Now that I have this data(altitude and azimuth), how can I plot it in something like this, with the coordinate system going like this?
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1answer
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Brightness, altitude & azimuth for satellites?

I'm using the heavens-above website to identify a satellite I've seen several nights this week. The question is related to how I can search the satellites table with the information I can provide. ...
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3answers
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Perceiving movement of stars

Are there any stars visible to the naked eye whose position, over a normal human lifetime, can be seen to have changed (relative to other stars in the vicinity)?
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Moving objects in the sky tonight 27th March 2020 [duplicate]

Multiple moving objects not in a line. The are staggered single line and in groups of two or three. One or two moved downward. They had a dim light orangey colour. It was not obvious that these ...
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2answers
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Which kinds of astronomical observations most need to avoid the Moon being up?

This comment to Did nobody in the Astronomy community think 12,000 new satellites in LEO might be a problem? links to Phys.org's New ESO study evaluates impact of satellite constellations on ...
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Why the Milky Way appears to be arching across the sky?

The Milky Way galaxy is disc-shaped and earth is in its plane: (source) In the following image the milky way appears to be arcing across the sky: (source) This looks like an out of plane view of ...
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Is there a place where one can see the beginning of the universe? [duplicate]

If the night sky Is dark because we’re seeing the world as it was a long time ago, when there wasn’t much to see, is there a place on the universe where we can see the universe at the beginning of ...
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1answer
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Encode place and date in star pattern

Disclaimer: I'm an astronomy noob You sometimes see in (B?) movies, that they infer dates from sky patterns. I was asking myself if you can encode a place and date in a mostly meaningful pattern? ...
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1answer
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Sky from Equator at 8,000 years Before Present?

The Stellarium software allows future views of the sky. I need an online resource (planetarium projector?) that shows pre-historical views, and from the Equator at 8,000 years before the present.
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Any night sky image databases

I was wondering if there were any available databases for photos of the night sky. It doesn't have to feature pictures of any particular star, just has to be a large collection of photos from the ...
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2answers
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Why do I see rainbows around the moon?

Regularly, I see rainbows around the moon. Here is approximately what I see: Right at the edge of the moon, I see a bright blue ring of light. Further out, I see an inner rainbow. This is not as ...