Questions tagged [estimate]

Questions asking for approximate results by making an educated, reasonable guess based on the information given.

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Size of the Unobservable Universe

If you search that question on Google, the answers will be "250 times the size of the observable universe" or "more than 15.000.000 the size of the observable universe". Both of ...
jack_O'Dim's user avatar
5 votes
3 answers
1k views

How do I estimate the difference in the speed of time flow between Earth and a distant star?

I can use data from Gaia Mission to estimate radial velocity(from RVS) and proper motion(from parallax), to take into account special relativity. The remaining question is what data should I use to ...
FrogOfJuly's user avatar
1 vote
1 answer
33 views

Magnitude difference between companion in binary from mass difference in binaries

Is there any hypothesis on how to estimate the difference between visual magnitudes of binary components based on their masses? Thank you
Anna-Kat's user avatar
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1 vote
1 answer
52 views

What is the period of Gamma Cassiopeiae?

Gamma Cassiopeiae is a variable star whose magnitude changes between 1.6 and 3. On what timescale does it vary? The Wikipedia page says that it is irregular, but what is the timescale of its ...
usernumber's user avatar
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24 votes
1 answer
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How long between the moment a meteor is first visible and the moment a meteorite hits the ground?

A meteor is usually only visible for a couple seconds at most, but I would guess that it usually stops being visible high above the ground. Meteors often don't make it to the ground as they completely ...
usernumber's user avatar
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2 votes
0 answers
57 views

How scientists estimated the number of near-Earth supernovae over the last 11 million years?

According to this article on wikipedia, An estimated 20 supernova explosions have happened within 300 pc of the Earth over ...
user avatar
4 votes
2 answers
110 views

Photometric redshift - empirical methods (machine learning)

I am currently learning about estimation of photometric redshifts with machine learning methods (or empirical methods in general). These methods use the knowledge about the photometry and the ...
user120112's user avatar
6 votes
1 answer
119 views

3C273 jet mass estimate

In this picture of 3C273, we can see a jet—estimated to be around 200,000 light-years long—being emitted. I'm trying to find an estimate for the mass of the jet. It's a stream of ...
Jim421616's user avatar
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2 votes
0 answers
50 views

In SETI has anyone calculated an estimate of the mean time between observations?

So the Drake Equation, proposed by Frank Drake, is often cited as a means to estimate the number of intelligent civilizations that exist in the observable universe. Initial calculations by Drake ...
docscience's user avatar
5 votes
1 answer
203 views

How did Batygin estimate when Planet Nine was ejected?

Konstantin Batygin has estimated that if Planet Nine was ejected, it would have been ejected 3-10 million years after the formation of the Solar System. I'm curious as to how he arrived at this ...
HDE 226868's user avatar
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1 vote
2 answers
565 views

Number of stars & planets in Milky Way Galaxy?

Is there any specific numbers on stars & planets count on Milky Way Galaxy ?
Mani's user avatar
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