Questions tagged [star]

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3
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1answer
160 views

How do we measure the brightness of the stars?

How do scientists measure the brightness of so distant stars?
3
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2answers
3k views

Calculating star radius from temperature and absolute magnitude - what am I missing?

In an attempt to visualise nearby stars, I've tried to get the star radius (measured in solar radii) using the equation provided on the following site: http://cas.sdss.org/dr4/en/proj/advanced/hr/...
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1answer
48 views

Orphaned star systems and intergalactic travel (in fictional context)

Context: I'm looking for some authority on a particular idea that I brought up in regards to a new update brought out for a space travel sim game, Elite Dangerous The vessels in that game can travel ...
1
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1answer
69 views

Calculating the orientation of the night sky

How would one calculate the rotation/tilt of the earth to simulate the Night Sky in a self-written tool or app. I am trying to built an app for my telescope to show me on my phone what I am looking at....
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4answers
966 views

Visible Stars in Andromeda Galaxy

So when I look at images taken of Andromeda, I see a lot of individual stars. Image by André van der Hoeven It seems to me that the actual individual stars that far away would be too small to ...
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0answers
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Lights moving fast and in a straight line coming from the northwest headed southeast tonight at 9:15CST [duplicate]

What is going on tonight? Bright lights in the same high orbit moving very fast across the night sky from Northwest heading southeast...then 10 minutes later same line but far fewer almost in ...
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5answers
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Stars in constellation patterns by catalogue number?

I need a resource that can tell me the stars that make up a constellation (pattern), preferably by Henry Draper or some catalogue number? All i can find is lists of every star in a constellation (area)...
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1answer
63 views

How is the distance of a star from Earth calculated in the HYG star database

The HYG star database can be found here From the hygdata_v3.csv file, how are the cartesian (x,y,z) coordinates calculated? (Is there a mathematical formula for this?) And in the dso.csv file, there ...
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0answers
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Fast moving stars at equal distance in straight line 18.04.2020 evening [duplicate]

Yesterday, I have observed fast moving bright stars at equal distance in straight line (18 March 2020) in Germany around 20:00 in night. I was facing the east direction. What could be the reason for ...
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1answer
212 views

When Betelgeuse goes supernova, will the explosion hit any neighboring stars?

There is evidence Betelgeuse might go supernova "soon". Are there any stars in the vicinity of Betelgeuse that are close enough that they will be hit by the explosion of this supernova? What would be ...
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1answer
64 views

Was it a space station?

I just looked at the sky and saw a star, not so bright but moving very fast and in almost a minute it disappeared, as it was so fast. Timing was in between 9.35-9.45 PM in Nuremberg, Germany. My ...
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0answers
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Identify moving object in the sky at night?

So last night 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 difficult to ...
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5answers
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Are the stars in constellation located in a plane or they are in different distances

Are the stars in constellation located in a plane or they are in different distances from each other and when we observe them from the Earth we think they are all in a plane?
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0answers
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How to extract surface temperature of star from B-V magnitude over all ranges of B-V?

Background: According to the wikipedia article about the color index, one can approximate the effective surface temperature of a star from its B-V index by the ...
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3answers
521 views

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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1answer
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Is there a relationship between stars' absolute magnitude, spectral class and relative location in a cluster?

I am interested to know whether a pattern has been observed with regard to the characteristics of a star (in particular, its absolute magnitude and spectral class) and its location relative to others ...
2
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1answer
61 views

How can I check if we can observe a certain star (given its equatorial coordinates) from a certain location on Earth (given its DMS coordinates)?

I am given the equatorial coordinates of a star (e.g. Sirius has RA: 6h45m8.9s and Dec = -16°42'52.1"). Now my question is: can we observe this star from a specific location on Earth (e.g. from ...
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0answers
23 views

Line of “stars” following one another [duplicate]

Last night (2020.04.08 9.20PM Balerna-TIcino -Switzerland) me and my husband seen a line of "stars, moving in a straight line at first with some of those moving in different directions. They kept ...
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1answer
580 views

What is the most appropriate way to estimate the helium composition of a star?

Say we have to estimate the helium content in Proxima Centauri. We begin by calculating the content of helium in the Sun (source): $24.85$% of $2.10^{30}$ kg. Mostly all the energy is generated due ...
6
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2answers
791 views

What is the furthest star for which we can measure the diameter?

If a star is close enough that we can measure its parallax and that it doesn't appear point-like, then we can deduce its diameter. Can we measure the diameter of all the stars for which we can measure ...
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0answers
29 views

I saw something move in the sky and i am not sure what it was :( [duplicate]

I saw a little light from between two stars(it had the same size as the star) moving in a straight line and then it went from one side of the moon and came out from the other end(i am not sure but i ...
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1answer
122 views

How do K, F, A and B stars die?

I know that M (red dwarf) main-sequence stars slowly fade to white dwarf stars, and that G (yellow dwarf) main-sequence stars become red giants and then shed their outer layers in a planetary nebula ...
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0answers
30 views

What were the moving lights in the sky tonight? [duplicate]

Tonight we saw moving lights in the sky south east of Orion's belt. Anyone any ideas what they were? About 20 of them all going in the same direction east.
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1answer
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What is the precession of the star S62? [closed]

What is the angle of precession of the star S62 orbiting the Milky Way supermassive black hole?
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0answers
51 views

Alien “train” in night sky any one else seen these [duplicate]

on march 1 2020 my sister and I were out about 530am and near the big dipper stars were moving one the two one then two (* ** * **) for about 15 minutes this continues like a train moving they seem to ...
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2answers
2k views

Does any iron fuse in stars before they go supernova?

I understand that iron and all heavier elements consume more energy to produce than they make, and that is what eventually leads to a supernova. I also understand that a lot of the heavier elements ...
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1answer
68 views

how to calculate distance between galaxies in the distant past

for example, assume there is a high redshift galaxy called "A" with z=6, so how to calculate the distance between us and another galaxy B when the light left the galaxy A? For example, say B has a ...
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0answers
31 views

Yesterday I saw multiple moving objects in my telescope when i was looking for M31. Do you have any idea what it could be? [duplicate]

Yesterday, when I was looking at the Andromeda Galaxy in my telescope. I saw three star like objects, moving across the sky. I followed them to see what is was, though i still don't know. They where ...
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3answers
151 views

Is there a stellar database that indicates how long ago stars in our Galaxy formed?

There are several ways of determining the age of a star: its position in the HR diagram, the presence of a protoplanetary disk, it belonging to a cluster... When did the stars in our Galaxy form? Do ...
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0answers
36 views

Stars moving in line and some moves around [duplicate]

I am from South Africa this morning around 05:00 I saw 7 to 9 stars moving in line and some moves around. What cause that to happen. Because I have never saw something like that before.
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0answers
67 views

What is the dielectric constant of a star?

1) What is the dielectric constant of a star, especially its corona? Is it of order 1 or is it quite large? 2) How much do "impurities" (elements other than H and He) affect the dielectric constant?
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1answer
75 views

Estimating star temperature

I have an assignment, where I'm supposed to estimate the temperature of a star in at least two different ways, and determine which of the approaches gives the most reliable estimate. All that is given ...
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1answer
1k views

How much illumination do the background stars provide?

I'm trying to get a better understanding of what things look like in "outer space." The main problem I'm trying to solve right now, is how much illumination is provided by the background stars. Is it ...
2
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1answer
150 views

Estimating a star's radius, temperature, and luminosity based on its mass

(See updated figure and description below.) I've been trying to generate ballpark estimates for the radius, temperature and luminosity of stars in the main sequence based solely on their masses (...
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1answer
47 views

Q: star scaling calculation

If in our neighborhood of the Milky Way, the typical spacing between stars is 1 parsec, and the relative velocities between neighboring stars are of order 20 km/sec, what would the spacing between ...
5
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1answer
206 views

Proxima as Supernova

Follow this question. If a star at the same distance from us as, say, Proxima Centauri had exploded as a Supernova 4 years ago (I know, it can't explode as supernova, let's say it can)... How bright ...
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3answers
5k views

What is this web on the surface of the Sun?

I was going through my Social Media Feed and found the attached post too frequent. The caption reads this is the best image of our Sun. Just as an example, the Universe Today's This is the Highest ...
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2answers
209 views

What star is the closest to Betelgeuse?

Based on this answer, I should be able to figure out this question, if I know the distance between Betelgeuse and its nearest neighbor. So what is Betelgeuse's nearest neighbor? I do mean the ...
11
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1answer
1k views

What is a hypernova and have we observed any?

Inspired by the question "What does it mean for a star to go nova or supernova? Can I safely observe these?", I am curious about what hypernovas are? Have we observed any occurring, or the at least ...
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2answers
87 views

Why does the Gaia color-magnitude diagram have this shape?

I was looking at the visualization tools of Gaia, and tried plotting a color-magnitude diagram. On the right hand side of the image, photGMeanMag (mag) (the amount ...
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2answers
366 views

What planets or exoplanets orbit the Sun’s elder twin HIP 102152?

Has anyone done any research on the planets that orbit the HIP102152? Since that star is similar to ours and older, I postulate that it’s likely those planets are most worthwhile searching for ...
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1answer
119 views

When exactly star Sirius shines into the queen's chamber of Great Pyramid?

I read that Great Pyramid was built to resonate with Sirius by aligning an airshaft that connected to queen's chamber. That is, the light of Sirius going through the shaft would be able to shine into ...
11
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3answers
283 views

What do the fusing 'onion layers' of a pre-supernova star look like to scale?

I'm sure we've all seen the diagrams of various layers of element fusion from hydrogen to silicon in a star that's just about to go supernova. (Picture from courses.lumenlearning.com) I suspect ...
2
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1answer
65 views

How can a star's rotation speed be measured?

How can a star's rotation speed be measured? If stars could be resolved, then you could use the Doppler shift to see that half of the star is bluer and the other half is redder, but stars (other ...
2
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1answer
135 views

“Juxtapositions” of moon,stars and planets in the sky,

What are "Juxtapositions" of the Moon, stars and planets called? When the Moon, stars and planets take exactly the same position after few or many years, how to describe the positions and what is ...
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2answers
58 views

How variable does a star have to be, to be a variable star?

Variable stars are stars whose apparent magnitude varies. But there are so many phenomena that can cause a star to be variable, that I would expect all stars to be variable. A rotating star has a ...
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0answers
38 views

Henyey method for interior parts of the star

Does there exist a code that implements Henyey method for interior parts of the star?
4
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1answer
226 views

Creating an HR diagram from tabulated stellar data

I teach statistics and study Astronomy. I'd like to create an activity for my statistics students using star data. They could enter the data into Excel and create an HR diagram. We are currently ...
2
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1answer
71 views

Redshift and Velocity relation

Let us say that we have an object so its total velocity is defined as \begin{equation} v_{tot} = v_{pec} + V_{rec} \end{equation} Where \begin{equation} V_{rec} = H_0r \end{equation} and \...
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5answers
529 views

Without using absolute magnitudes or isochrones, how might we tell a star's age and evolutionary status?

Usual methods of estimating stellar ages involve isochrone approximations. It can also help to estimate a star's radius by correlating its absolute magnitude with effective temperature and apparent ...

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