3
votes
1answer
86 views

What is the bluest narrow band filter mounted on ground based telescopes?

If we want to check a QSO's lyman alpha narrow band image, could a ground based telescope do that? I mean under the circumstance that its lyman alpha shifts to 3300A.
2
votes
1answer
42 views

Hour angle sunrise calculation problem

I am trying to program a sunrise/sunset calculator using this formula tutorial. If you follow the steps, eventually you get to this formula for "H" (the "hour angle"): $H = \arccos( [\sin(-0.83) - ...
2
votes
1answer
46 views

Calculate telescope orientation based on RA, DEC and Lat/Long

I'm parsing FITS files for a project based on data from a telescope. These files include 'DEC', 'RA' and lat long values. I understand roughly the concept of celestial coordinates and I assume that ...
2
votes
1answer
40 views

Maximum Amplitude of a Lissajous Orbiting Object in a L4 or L5 Position

I stumbled on The Lagrangian points during some wikipedia reading. After looking at the gravity contours, I naturally come to the conclusion that the L4 & L5 should have a wave pattern and then ...
2
votes
1answer
54 views

Black dwarf binary systems

I know black dwarf stars do not exist yet, and that they are what white dwarfs end up after a long time. The question is really simple: would it be possible to have a binary system in which one of the ...
1
vote
1answer
50 views

seasons elongating and shortening

I have heard of years with longer summers and winters and shorter springs and falls and vice versa because of a change in the earths axis. Is this from the procession that causes the season switch ...
1
vote
1answer
14 views

What are possible methods of discerning a starburst AGN composite galaxy?

I'm currently working on an independent project that involves discerning starburst galaxies that are themselves within active galaxies. I would assume radio observations would be best to discern star ...
0
votes
1answer
42 views

How did the reionization epoch make the universe “transparent”?

I've been reading about the reionization epoch of the universe, and it isn't entirely clear to me. As I understand it, very shortly after the big bang the universe was ionized, with the electrons ...
0
votes
1answer
34 views

What did I see streaking across the sky last night?

I was enjoying a casual naked eye view of the summer sky last night around midnight in a new jersey beach town. The sky was pretty clear for around here.The Milkyway was just visible and there was no ...
7
votes
0answers
89 views

Dark Flow: statistical limits on existence

Dark Flow has been thrown around as a term a lot lately, especially with the latest Planck results. New Scientist reported last year that it was now statistically improbable, but the paper by Atrio ...
6
votes
0answers
61 views

How many galaxies disappear beyond the Hubble Bubble horizon every year now?

The accelerating expansion of space means that the space between us and far away galaxies expands faster than light can travel through space. There is a horizon of possible observation beyond which ...
6
votes
0answers
103 views

Determining effect of small variable force on planetary perihelion precession

Is there an analytical technique for determining the effect of a small variable transverse acceleration upon the rate of precession of a planet orbitting around the Sun according to Newtonian gravity ...
4
votes
0answers
47 views

Are there large underground caverns on Mars?

Scientists talk about the possibility of life underground on Mars, and I assume they are talking about microscopic life that can live in small gaps in the soil or rock. But is there any evidence that ...
4
votes
0answers
45 views

What was the greatest spatial extent of the Asteroid Belt prior to the Late Heavy Bombardment?

Reading the article On the asteroid belt’s orbital and size distribution (Gladman et al. 2009), there is an interest point made: asteroids a few kilometers and smaller in size are recent ...
4
votes
0answers
44 views

What are the current observational limits on the existence of Dyson spheres/swarms/rings?

A Dyson sphere/swarm/ring is a hypothetical structure an extra-terrestrial entity would construct to collect a large fraction of its host star's light, and would likely generate a fairly strong ...
3
votes
0answers
79 views

Magnetic fields of peculiar HgMn A type stars

Are HgMn (peculiar A type) stars really possess global magnetic fields? See, for example, paper Hubrig et al. 2012: http://arxiv.org/abs/1208.2910
2
votes
0answers
86 views

is there any theory or observational evidence that our universe is electrically neutral or not?

It seems our universe is neutral in large scale. There is CP violationwiki problem about matter and dark matter. Similarly is there any theory about whether our universe is electrically neutral? ...
2
votes
0answers
50 views

what is the farthest object we've been able to bounce signals off of to date?

I know people bounced lasers off of Venus and Mercury in 1960s in order to test the Shapiro delay. Since then, we've developed higher-power lasers and radio transmitters (Bolshakovo transmitter). ...
2
votes
0answers
76 views

How many new galaxies enter the observable universe each day/year/decade?

Each day light has more time to reach our eyes from distant galaxies. In one day, light travels 2.59×10^10 km. So our observable universe (assuming my simple math skills apply here and there isn't ...
2
votes
0answers
38 views

Exoplanet naming conventions

I'm looking for any exoplanet nomenclature, official, semi-official, proposed, or just a good idea, beyond what can already be found on Wikipedia at ...
2
votes
0answers
39 views

Why can primordial tensor perturbations of the CMB be ascribed to gravitational waves?

Why can primordial tensor perturbations of the CMB be ascribed to gravitational waves? Is this attribution unique, or are there other michanisms that could lead to the ecitation of tensor modes? In ...
2
votes
0answers
24 views

need data-point: actual counts per second with APD (avalanche photodiode) detector

I'm designing a sensor system to perform specialized [astronomy and space-sciences] experiments, and need a "reality check" to support or adjust my theoretical calculations. What I need is the ...
1
vote
0answers
40 views

Can astronomical radio sources be used as a verifiable randomness beacon?

A randomness beacon is a source of random data that is broadcast to multiple parties. Users listening to the beacon receive the same sequence of random strings and no one can predict the values in ...
1
vote
0answers
34 views

What is the explanation for rapid inflation just after the big bang?

I often hear about cosmic inflation occurring rapidly after the Big Bang, but have never came across any explanation for it. What supposedly caused this inflationary period in the early universe? ...
1
vote
0answers
22 views

Singularity in Laplace Method for Orbit Determination

I have a question about Laplace angle-only method for orbit determination where the line of sight vectors are being interpolated. I read somewhere that the method fails (due to a matrix being ...
1
vote
0answers
12 views

Why does Mars' experience an 'ice age' at high axis obliquity, when Earth experiences an ice age at low axis obliquity

This paper here goes into some detail about how Mars' experiences its own form of 'ice ages' on a quasi periodic basis driven by the wobbling of its axis. The main mechanism outlined is that the ...
1
vote
0answers
11 views

Is Mars' mantle homogeneous or heterogeneous and what might this say about mantle convection?

A supervisor of mine made an off-hand comment about the fact that Mars used to have plate tectonics, and there is evidence that Mars used to have plate tectonics, however now it does not. The theory ...
1
vote
0answers
82 views

In 2016, the summer solstice will coincide with a full moon. How often does this happen?

I found that the solstices work on a 400 year cycle based on this. I can't find anything similar for the lunar cycle. Is there a formula I can use to calculate the date of the full moon?
1
vote
0answers
87 views

How likely and severe is the threat of a gamma ray burst to earth?

In the National Geographic article: http://news.nationalgeographic.com/news/2009/04/090403-gamma-ray-extinction_2.html it is suggested that a gamma ray burst likely caused a mass extinction in earth's ...
1
vote
0answers
26 views

Can Space-Time Itself Have Energy Qualities Like Momentum?

Hypothetically, if space could be moved or scaled, what would happen to everything inside? I'd like to know if an element of momentum could be transferred to objects by contorting space-time. Other ...
1
vote
0answers
30 views

Intrasolar planetary surface temperature change divergence from Earth

Considering the vast amount of insulating gas emitted by human activity on Earth without a coincident release on all other planets in the solar system as well as the phenomenon that planets in a solar ...
1
vote
0answers
39 views

How exactly can the hypothetical conformal invariance of the CMB spectrum be established by analyzing tensor modes?

In the introduction of this paper at the top of p11, it is mentioned that a hypothetical enhancement of the scale invariance of the CMB spectrum to conformal invariance could potentially be ...
1
vote
0answers
25 views

local stellar mapping data

I've been playing around with Near Star Map, and I think I kind of want something more sophisticated, so for all stars within 100ly/30pc, is the following known? velocity (it would be nice to have a ...
0
votes
0answers
14 views

Landing on an “earth-like” planet (practical application)

This may not belong here in astronomy and my apologies if that's the case. The hypothetical: We find, and are able to travel to (in a reasonably short amount of time), a planet that is for all intents ...
0
votes
0answers
8 views

What known comets are binary?

Many asteroids are today known to be binary, to have "moons". But what comets are known to be binary? Or what fraction of them are theoretically thought to be binary? And if possible, then separate ...
0
votes
0answers
27 views

Are ascending node of sun, the point of intersection of prime meridian and equator and center of earth all collinear?

I did a bit of googling but couldn't find the exact answer, so are the following 3 points collinear or not ? 1_center of earth 2_ascending(or descending) node of sun 3_point of intersection of ...
0
votes
0answers
18 views

What is frequency range?

Using the NED, you can search via frequency range corresponding to the selected pass band filter. I'm a beginner here and don't really understand. Here's the quote: NOTES: Objects with ...
0
votes
0answers
8 views

Classification of a Comet

Google's definition of a comet is: a celestial object consisting of a nucleus of ice and dust and, when near the sun, a ‘tail’ of gas and dust particles pointing away from the sun. This ...
0
votes
0answers
22 views

Alt-Az or Polar?

I have a Meade wedge that I am to install on one of their LX200 telescopes. Will I be able to align in alt-az afterwards? Is polar easier or harder to make an alignment? Any other tips welcome. Thanks ...
0
votes
0answers
29 views

Derivation of the formula for longitude of ascending node for a satellite

I've been looking into the document IS-GPS-200H to understand how to calculate satellite location in the ECEF coordinate. I am having problem understanding the formula to derive $\Omega$, the ...
0
votes
0answers
22 views

Is it difficult to see DSO in your eyepiece?

I want to know if bringing the image of a DSO in eyepiece generally represents a problem for beginners in astronomy.
0
votes
0answers
27 views

In regards to the holographic principle, what exactly is information?

I'm having trouble understanding what exactly "information" is in the context of the holographic principle suggested by string theory. Can it be equated to a matrix of ones and zeros? Does this ...
0
votes
0answers
46 views

What is the galaxy M87 doing these days?

The massive elliptical galaxy M87 in the Virgo cluster is 53,490,000 light years away. It also contains one of the largest, heaviest supermassive black holes in the known Universe. But it's also my ...
0
votes
0answers
22 views

What is the ratio of cosmic microwave background radiation to normal radiation?

I would like to know the ratio of cosmic microwave background radiation to normal radiation in the universe. I am considering cosmic microwave background radiation to include the microwave, and any ...
0
votes
0answers
21 views

Why doesn't this paradox disprove (some) multiverse quantum gravitational theories?

As I understand it, one theory of the multiverse is that there are an infinite number of universes separated by small distances in other (than our observable 3/4) dimensions and that gravity is weak ...
0
votes
0answers
21 views

Coordinates of the Moon

How does one compute the right ascension and declination of the Moon at a given time (or for that matter, the altitude and azimuth)?
0
votes
0answers
37 views

Connection between Earth, Moon, Theia, and astroid belt?

Are there other fragments aside from the Moon that resulted from the collision of Earth and "Theia" (as it's called in recent main-stream press stories)? And if not, why not? And what happened to ...
0
votes
0answers
10 views

Any new info about solar flares hitting the Moon added by the LADEE mission?

This article from 2011 mentions simulations about the sputtering effect caused by a solar flare hitting the Moon: "We found that when this massive cloud of plasma strikes the moon, it acts like ...
0
votes
0answers
26 views

Torus of the AGN

How much do we know about the structure of the torus surrounding the galactic nuclei? Is the shape defined or still under speculations? And are there different structures for this torus possible i.e., ...
0
votes
0answers
31 views

Triangular Asterism Trigonometry

Using the SIMBAD database for Alnitak, Saiph, and Sirius -- i.e.: Alnitak: FK5 coord. (J2000): RA = 05 40 45.527 DEC = -01 56 33.26; Saiph; FK5 coord. (J2000): RA = 05 47 45.389 DEC = -09 40 10.58; ...

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