All Questions
Tagged with fundamental-astronomy observational-astronomy
21
questions
2
votes
0
answers
43
views
LSR and peculiar motion corrections to RAVE survey velocities
I am working towards getting a bunch of halo stars in our galaxy for my thesis. I am doing this with the help of a Toomre diagram and I am stuck. I am using the RAVE survey in conjunction with Gaia as ...
- 173
7
votes
1
answer
1k
views
On what basis is the information about the distance and velocity of the Voyager probes determined?
Voyager 1 was the first-ever object to reach interstellar space on
August 25, 2012 when it passed beyond the sun’s realm of plasma
influence (the heliosphere)[...]
(source)
Although some of their ...
- 213
4
votes
1
answer
468
views
Have there been studies of "old photons" to see just how constant things like Planck constant has been?
The question Are photons aged? and answers therein have got me thinking:
I vaguely remember hearing something about experiments where "old photons" were collected by large telescopes from very ...
- 30.7k
1
vote
1
answer
936
views
How Did Early Astronomers Measure Distances?
Prior to the era of radar and other forms of radio/RF/EM ranging, what approaches, methods, and techniques did early astronomers (e.g., Kepler, Cassini, Copernicus) use to measure the distance(s) from ...
user28134
2
votes
1
answer
2k
views
Making sense of the lomb-scargle periodogram
I am trying to use the periodogram to tell when a signal is periodic or not by following the tutorial for the astropy Lomb-scargle periodogram here.
http://docs.astropy.org/en/stable/stats/...
- 23
2
votes
1
answer
471
views
Simulating Noise in Astronomical Images
I want to add realistic noise to a simulated image but I am a little confused about the process. I want to have some Gaussian random noise representing the readout noise and to also add Poisson noise ...
- 147
1
vote
1
answer
280
views
The Solar Motion and the peculiar velocities of stars
Local standard Of Rest is the hypothetical origin of a reference system with respect to which the motions of all stars in some neighborhood of the sun average out to be zero
which type of motions of ...
- 351
3
votes
1
answer
103
views
If I look beyond (about same region, higher redshift) a galaxy, will I see its progenitors?
Is there a range of redhsift dz, such that if I look at z+dz from a massive object at redshift z, I will see its progenitors?
(in a LCDM scenario of halo assembling, with smaller halos evolving ...
user19333
2
votes
2
answers
183
views
How small a location is possible to identify when any visible star is at its zenith directly above?
How small an area on Earth is it possible to identify with any precision when any celestial object (star, planet, comet, nova) (visible with the naked eye alone) is at its zenith directly overhead?
--...
- 21
1
vote
1
answer
66
views
How to find if a set of objects lies within a given resolution (5 arcsec) on a telescope?
I am new to astronomy and I was given the task of finding out if there are objects which can't be resolved by a telescope of resolution 5 arcseconds.
I was given the values of RA and Dec of these ...
- 136
6
votes
1
answer
325
views
How to know that the 21cm Hydrogen line is the actual emission and not any other redshifted line?
Is it possible that we mistake some other wavelength emission to be 21 cm because of redshift?
- 503
2
votes
1
answer
75
views
The M-theory to understand black holes [closed]
I am a layman in astronomy. Can someone please explain it to me whether the M-theory can be used to explain what is happening in the centre of the black hole where the singularity exists? Or is it ...
- 49
4
votes
0
answers
61
views
Does an algorithm exist that takes an image of the night sky and tell you where in the milky way that perspective likely originates? [duplicate]
In Stargate they talk about using the stars on other planets to figure out their location. I know that's fiction, but it made me wonder if such an algorithm (with arguably little usefulness right now) ...
- 141
0
votes
1
answer
95
views
Frequency of transit in planar and non-planar planetary systems
Supposing that another planetary system is in one plane like our solar system, if let's say that the transit of one planet is visible then is it safe to also assume that all planets in the system must ...
- 11
1
vote
1
answer
154
views
does a minority of all planetary systems show transits?
do most or only a minority of all planetary systems to show transits?
I feel like its minority due to the random orientation of their orbits?
But the thing is I seem to find conflicting information.
...
- 11