Questions tagged [astrometrics]
11 questions
21
votes
6 answers
Given a photo of the Moon, taken from Earth, is it possible to calculate the position of the photographer's site?
Given a photo of the Moon, taken from Earth, is it possible to calculate the position (Earth longitude and latitude) of the photographer's site?
I am thinking about photos taken with a normal camera lens and not with a telescope, for example photos…
13
votes
2 answers
How is distance between sun and earth calculated?
How has the distance between sun and earth been calculated?
Also what is the size of the sun?
xyz
- 665
9
votes
3 answers
How are Cepheids used to evaluate their distance?
Cepheids are used to evaluate distances. What is the math and physics behind their use?
Stefano Borini
- 3,970
7
votes
1 answer
Reverse Sun position algorithm?
To find the sun's position (elevation, azimuth) we can use many algorithms including the PSA algorithm.
These algorithm share the fact that the input is the local time, longitude and latitude and the output is the elevation and azimuth.
is there any…
Mina Samy
5
votes
1 answer
A method to estimate the relative magnitude of a star using nearby stars
I remember a method to make a reasonable estimate of the magnitude of a given star X by using two other stars of known magnitude as references. The method used evaluation phrases like "the star X and the reference star appear to have the same…
Stefano Borini
- 3,970
4
votes
2 answers
Converting between Galactic and Ecliptic coordinates
I was hoping someone would be able to tell me the formula to convert between ecliptic and galactic coordinates. I've been able to convert values using http://lambda.gsfc.nasa.gov/toolbox/tb_coordconv.cfm but have no idea how they were able to…
Tim Mutton
- 141
4
votes
2 answers
How does one measure Earth's speed of revolution around the sun?
I know that there are several formulae that one can plug numbers into to arrive an estimate of Earth's speed around the sun (Kepler's third law for instance), but I'm wondering how these things are measured.
Since Earth is moving in an ellipse…
Kitchi
- 3,767
- 2
- 23
- 38
4
votes
2 answers
How do we measure distance using parallax?
This is a quick mock-up of how stars are measured using parallax method.
My question is :
How on earth (literally) do we measure the anfle $\theta$?
Is theta measured from the zenith of Earth? ie, Are the gray lines the zenith of earth?
Max Payne
- 639
2
votes
2 answers
IRIS alternative on mac?
I need to process some images taken from a telescope to determine the intensity of an astroid.
This way I can determine the rotation period of this asteroid.
The pictures were taken the usual way (I guess, I'm not an astronomer, this is a school…
romeovs
- 392
2
votes
0 answers
Calculating distance to an asteroid on a given day
I'd like to calculate the distance between the Earth and an asteroid at a given date. Is this possible using the data from JPL's small-body database? Is there a better way?
ty.
1
vote
1 answer
Perturbations of planetary Orbits
I have, for years, been an Astronomy and physics nerd. For the first while, I was a total astronomy nerd. Then I slowly transitioned into physics and have been, for less than a year, a physics nerd. In this shirt while, I have taught my self…
Damon Blevins
- 479