# All Questions

10 views

### Does 2 merging black holes necessarily make a quasar?

2 black holes are about to merge to become a larger black hole. Does this mean it'll become a quasar? From what I know, quasars are supermassive black holes or a collective amount of them. So, if it ...
12 views

### If black hole can swallow light then why don't it do the same for quasar?

My question actually is that if a black hole can swallow everything even the light then when the two black holes combines it forms a quasar which is very high light ,then why don't it swallow that ...
3 views

### Are all models of ocean planets thoeretically cloud covered?

Take for example an ocean planet slightly smaller than the Earth. Let's say it has a planet-wide ocean that is on the average 10 miles deep. Say for argument sake, that there is a molten, rotating ...
5 views

### Moon's negative greenhouse effect?

Using the standard formula for effective temperature of a planet, Venus has T(eff)=227K, Earth has T(eff)=255K and Mars has T(eff)=217K (using albedo for Venus a=0.7, Earth a=0.367, Mars a=0.25). ...
177 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.
3k views

### Average amount of annual daylight at any place on earth

If this is the wrong group please direct me to the correct one. It seems intuitively obvious that the amount of daylight per annum should be the same for any latitude on earth. For example, 12 hours ...
17 views

### Restfull web-service providing orbital data of solar bodies (planets, comets, asteroids, dwarf planets)

I would like to be able to connect to a web-service and retrieve JSON data containing information on current (as of today or so) orbits of planets, comets, asteroides, dward planets in our solar ...
72 views

### Can we see the past image of Earth because of curving light by massive objects?

I know massive objects can curve light, can we capture the image of past Earth by lights from Earth that curved by massive objects?
145 views

### If Alpha Centauri A's solar system exactly mirrored our own, what would we be able to detect?

Suppose there was an exact replica of our solar system 4.4 ly away (people included). What would we be able to detect and with what telescope(s)? Which planets? Could we detect radio transmissions ...
41 views

### Why are the magnetic poles of a pulsar so far off the rotational axis, yet stable?

My understanding is that a pulsar is a neutron star whose magnetic poles don't coincide with the rotational poles and whose magnetic poles sweep through Earth (allowing us to hear radio noise). If we ...
285 views

### Does Sun have a reflection on Earth?

The new Google Maps1 presents an actual view of Earth, with the current position of Sun illuminating half part of Earth in real time. It is quite an exquisite view. My question is based on the ...
28 views

### Is Ceres a terrestrial-type (dwarf) planet?

Does Ceres belong to the terrestrial-type celestial bodies?
18 views

### Finding a location using the direction of shadow, UT and date approximately

Does anyone know how to find a location by using : the direction of shadow relative to the normal (for example azimuth angle) the Universal time (UT) and date I have a satellite image and I know ...
78 views

### Brightest star of the night sky

I read in many astronomy sites that Sirius is the brightest star of the night sky and that Orion’s Belt points to Sirius. For some days I have been regularly watching Orion (just before dawn) but the ...
21 views

### Is it possible to see a circular explosion in space from earth?

If these were not explosions could it have been space debris
27 views

### Double Planet Orbiting Wide Binary Star?

Right now I'm writing a sci-fi story that develops in a double planet. But that's not all, the double planet (along with a couple more planets) orbit a big star and the whole system is orbited by ...
82 views

### Stellarium 0.10.4: planet orbits change over time?

If I draw the orbit of Mars in stellarium 0.10.4 for 23 Sep 2015, it passes south of Chi Leonis: If I advance the date to 17 Oct 2015, however, the orbit of Mars correctly goes right through Chi ...
53 views

### Is ours the first universe?

I see here that after a very long time into the future, "Estimated time for random quantum fluctuations to generate a new Big Bang". This begs the question, do we speculate that our big bang was the ...
178 views

### How to calculate a planet's current position within the solar system

I'm making an application that needs to calculate a planet's current position within the solar system - I don't want to calculate its position in the sky. For example, what I want to do is exactly ...
38 views

### Successor to the Hubble Telescope

Are there any plans for the 'Hubble2'? Maybe with an even bigger mirror capable of even finer resolution, to look even deeper into the origins of the universe? If so, when can we expect to see it in ...
25 views

### What does the BinTableHDU store?

I'm just getting started with very primitive analysis of FITS data, and I have a 'raw' FITS file which I don't know how to get different wavebands of data from (if this is even possible). ...
39 views

### Existence of multiple universe?

In this youtube video, Prof. Michio Kaku mentions there could be multiple universes and if there are, then there could be a worm hole to some other universe. My question is: We are not sure if the ...
38 views

### What constellation does sun occupy by location and date?

How can i find the location of the sun and which constellation it would occupy based on the location and date of year. for example: an observer is in Des Moines, Iowa on April 10th, which ...
428 views

### Gallery of 'actual images' from space?

Where can a gallery of actual unaltered photographic images taken in (or of) space be found? Specifically ones that are untouched, not colorized (not necessarily black and white, but they usually ...
123 views

### Are there are any photographs online that approximate what the Milky Way looks like to the unaided eye?

I love seeing all the long-exposure photographs of the Milky Way, but I'm going to Cherry Springs State Park in Pennsylvania next month, and I'm wondering if there are any photos that approximate what ...
223 views

### Could there be dark matter black holes?

Could dark matter compress and form black holes? Since dark matter is even more abundant than normal matter, a dark matter black hole should not be rare...right?
63 views

### If we found evidence of life on Mars, how would we know that it originated on Mars rather than Earth?

Consider this scenario. One of the probes sent to Mars either very soon, or within the next century, finds conclusive micro-fossil evidence that life once existed on Mars. One theory today that is ...
179 views

### Disc of the milky way

For those that haven't seen this link - please have a look as it's a an awe-inspiring 360 interactive panormic image of the milky way (may need a bit of time to load though!). I've found myself idly ...
224 views

### How to calculate conjunctions of 2 planets

So, the recent conjunction of Jupiter and Venus seems to have spawned lots of excitement over this "rare" event. But what I can't figure out, is exactly how rare it is. And I've seen such conflicting ...
84 views

### What light source can cause a shadow of a cloud onto the next cloud above?

Scenario- -Time & Environment-11:00pm Super Moon small town population 40,000 in Central Ca. -Nearest body of water is 80 miles away 4 small lakes of about 1 mile in diameter. -Pacific Ocean is ...
55 views

### What happens when two black holes collide?

There are many hypothesis saying that there will a collision between the milky way and Andromeda galaxy...so what happens when two black holes will collide?? And how will it effect the other objects ...
30 views

### From Mean Moon to True Moon in an old procedural calendar

This is a follow-up to How to interpret this old degree notation? It is about an old calendar system which generates a luni-solar calendar with a procedural method, using a handful of calculations ...
8 views

### How would we thrive on a planet whose rotational period is different than Earth's? [migrated]

Atmospheric pressure/composition, temperature, or gravity wouldn't be considered, or let's assume that all of that is the same as Earth's. Would we "rest/stay awake" however long or short it takes to ...
28 views

### Can you see pleiades and sirius at the same time on the sky?

I am would like to know if you can see pleiades and sirius on the sky at the same time from Greece? What time of the year would that be? And I would be very greatful if someone knows some interactive ...
112 views

### If a person were to die on the Moon or Mars, would the body decompose?

There wouldn't be enough oxygen for any bacteria to decompose the body, right? Not to mention, the radiation of space might kill off most organisms on it. So would it decompose, given millions of ...
38 views

### What are the cosmological ramifications if we probabilise and continuify the order of differentiation in $F=\frac{d(mv)}{dt}$? [migrated]

Newton's second law of motion states that $F=\frac{d(mv)}{dt}$. This is a first-order differential equation, in which the order of differentiation of momentum is 1. So we can write it ...
171 views

### Metallicity of Celestial Objects: Why “Metal = Non-metal”?

Metallicity of objects refers to the amount of chemical elements present in it other than Hydrogen and Helium. Note: The other elements may or may not be actual ...
700 views

### When will all eight planets in our solar system align?

Ignoring expansion of the universe, entropy, decaying orbits, and interference from any bodies colliding with or otherwise interfering with their orbits, will the eight planets known planets in our ...
51 views

### Luminosity Schechter function for galaxies

Just a question I am having trouble understanding. I have the Schechter luminosity function for galaxies, given as: ...
75 views

### Origin of the magnetic field of neutron stars

It seems a little counter intuitive that neutron stars possess such strong magnetic fields. Its electric charge is presumably zero, so however fast it spins, it shouldn't generate any magnetic field. ...
27 views

### Eclipses of Jupiter's Moon during Retrograde motion

When Jupiter is undergoing retrograde motion as seen from the Earth, would you expect the eclipses of Jupiter’s moons to occur several minutes early, several minutes late, or neither? Can someone ...
21 views

### How would the explosion and fallout of a nuclear bomb on the moon compare to one on earth?

What effects would the atmospheric and gravitational differences between the earth and the moon have on a nuclear bomb explosion and fallout?
100 views

### Are galaxies moving away from us faster than before?

Are all galaxies moving away from us at constant speed even those that may be moving in our direction as the space is being formed? How does nothingness appear to push matter? A black hole sucks as ...
32 views

### Why is metallicity important in the death of stars?

I always thought that mass was the sole determinant of a star's fate. Then I saw the table here. So why does metallicity influence a star's ability to become a black hole or neutron star? Does it have ...
58 views

### Do neutrinos have as much information as photons do?

If neutrino detectors keep improving so that a fair number of neutrinos can be observed, would they be as informative for astronomy as photons are? They are of course a very valuable complement to ...
24 views

### Low precision GMST formula clarification

According to the website http://aa.usno.navy.mil/faq/docs/GAST.php, a low-precision way of calculating the GMST is via the following formula: GMST = 18.697374558 + 24.06570982441908 D The website ...
38 views

### How does gradual crossing over of the Roche limit transform a planet or moon?

Some cartoon simulations (an example) of an object (assume here a large moon with Earth-like density) which crosses the Roche limit of a much more massive giant planet, illustrate a circle suddenly ...
18 views

### dataset of stars in the milky way galaxy [duplicate]

Does anyone have any idea were I can get a dataset of stars in the milky way galaxy, their mass and their planets and distance of planets from their star? I have tried various catalogs of NASA. I ...