Questions tagged [star]

Questions regarding large spheres of plasma undergoing fusion.

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1answer
29 views

How to use spectral flux density data while using Planck's law giving spectral radiance?

I'm currently working on a fun project in my free time where I'm trying to calculate the temperature, among other things, of stars based on their spectra. Since I have essentially no prior experience ...
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1answer
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Distance between objective lens and eyepiece

I am trying to make home telescope, I have a convex lens of focal length 1000mm and eyepiece (plano-convex) with 25mm focal length. What is the ideal distance between objective and eyepiece to see ...
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Can a star turn into a planet?

I have read in a magazine that a star can actually form back to a planet... is it true?! Does it mean all the planets in our galaxy can be revived back to what they were before?
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1answer
575 views

Why is detecting brown dwarfs difficult?

Why is detecting brown dwarf stars tedious and not always successful? They emit light in the infrared region, and given that we're surrounded by state-of-the-art technology in space today, why haven't ...
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1answer
44 views

Where do stellar classes names come from?

Under Morgan-Keenan classification stellar classes are called O, B, A, F, G, K, M, but what is the logic behind these letters? I can't see any pattern and I doubt they have just been chosen randomly. ...
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1answer
77 views

Is there a relation between mass, radius, and luminosity in deuterium-burning brown dwarfs?

I'm a worldbuilder and my setting has a lot of brown dwarfs. While I'm trying to keep my setting as science-compliant as possible, I can't seem to find any resources for brown dwarfs like there are ...
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2answers
119 views

Best way to simulate star sizes to scale in celestial sphere

Using the Hipparcos catalogue, I am trying to create a celestial sphere. As all the stars are a fixed distance from the centre of this sphere, the only way to differentiate the distances and magnitude ...
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1answer
85 views

Unable to detect stars and constellations in simulation of stars from the Hipparcos catalogue

I am creating a planetarium program using Unity3D and C# to plot out stars from the Hipparcos catalogue. Using the Plx, _RA.icrs and _DE.icrs columns of the dataset, I have managed to work the ...
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1answer
49 views

What equipment and techniques were used to study Betelgeuse's diameter in 1920?

Comments below What is the maximum distance measurable with parallax? discuss challenges associated with parallax measurements of Betelgeuse and link to Wikipedia’s Betelgeuse; Distance measurements ...
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Bunch of stars moving on sky in triangular and different other shapes [duplicate]

Today I saw different Stars are moving on the sky in shapes of triangle and some randomly. its about 4:20 am in Nasarpur Pakistan and last star I saw at 4:32 am. They are moving in direction (North ...
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1answer
93 views

What are the necessary steps required for calculating the size of a star? [closed]

Title pretty much says it all. Basically, what exact variables are used, and what steps need to be taken, in the calculation of the size of a star? Preferably, some example data for how a the size of ...
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3answers
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A question about star names… E.G. CW Tauri, DZ Bootis, IQ Lupi, EU Eridani

Take the following examples of star names/identifications:- Regulus is the common name for a star. HIP49669 is the Hipparcos ID for the star HD87901 is the Henry Daper ID for the star 32 Leonis is ...
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any proof that stars are born, and die?

I've heard from a lot of people that stars are "born" (usually from black holes), then grow bigger, then eventually "die" by some kind of supernova etc., but have any of these events actually been ...
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957 views

Are there neutron stars whose magnetic axis and rotating axis are the same, and if so what will happen?

I know that there's probably a higher chance of having a neutron star that has its magnetic axis inclined to the rotational axis rather than having it perfectly aligned. If they are not aligned, the ...
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1answer
118 views

How do we measure the brightness of the stars?

How do scientists measure the brightness of so distant stars?
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1answer
45 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 ...
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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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1answer
56 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
879 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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1answer
51 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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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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1answer
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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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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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1answer
36 views

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 ...
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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
578 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 ...
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2answers
772 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
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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
114 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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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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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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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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1answer
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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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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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0answers
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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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66 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
66 views

Stellar age determination - code

I'm trying to determine the age of some stars. I have many parameters that characterize these stars: $T_{eff}$ ,log ${g}$ ,$[Fe/H]$, $V$... I've tried to use the isochrones package but so far no ...
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1answer
73 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
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 ...
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2answers
363 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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2answers
200 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 ...
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2answers
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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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1answer
63 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 ...
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2answers
57 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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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?
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1answer
199 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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I saw this ball of light moving across the sky [duplicate]

As I stated in the title, I saw this ball of light moving across the sky. It wasn't moving fast, but it wasn't moving slow. So, I was sitting my dad's car when I looked through the windshield and at ...
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1answer
242 views

How much more life could the Sun acquire via star lifting?

It has been proposed before that we could use this technique to remove hydrogen from the Sun to lower it's rate of fusion and extend it's life, so it doesn't fry our planet. I am wondering how much ...
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1answer
287 views

Distance to Proxima Centauri (Gaia VS New Horizons parallax program)

The current best parallax measurement for the nearest star to the Solar System, Proxima Centauri, has been given by the European Space Agency's Gaia mission. This is $768.5004\; \pm \; 0.2030 \; mas$ (...

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