1
vote
1answer
9 views

How large must an object be to be seen through a telescope?

I've studied this in a few optics classes before, but I'm drawing a blank at the moment. If I know the aperture size and focal length of a telescope, as well as how far away the object I want to view ...
0
votes
1answer
11 views

Hubble law, cosmological redshift and distance

I have got confused with some cosmology formulas which calculate distance. The most famous formula is indeed the Hubble law which says (nowadays) velocity is proportional to Hubble's parameter at ...
2
votes
0answers
17 views

How to read NOAA/NASA GOES satellite data?

I requested satellite image data (GVAR_IMG) for a project that I am working on from the GOES satellite, but I don't know what format it's in or how to read it. When I open it with a text editor it is ...
5
votes
1answer
70 views

How did New Horizons take such well-lit pictures of Pluto?

The photos of Pluto from New Horizons are truly beautiful. But considering that Pluto is so far away from its nearest start - our Sun - how is it so well lit up? Did the New Horizons have a massive ...
3
votes
3answers
37 views

How much more massive would Pluto have to be to clear its neighborhood?

How much more massive would Pluto have to be to clear its neighborhood?
0
votes
1answer
39 views

Is expanding universe adding potential energy?

A system with two massive bodies has potential energy proportional to their separation. Since the universe is expanding, is the potential (and total?) energy of such a system slowly increasing? What ...
3
votes
1answer
255 views

How can a planet have a 90° inclination?

Planetary systems as we understand it exist from a disk of mass when the parent star is young. That's why all our planets are in the same plane, or close to it. See also Why is the solar system ...
2
votes
0answers
21 views

Orbits in a binary star system

I know of three sets of stable orbits in a binary star system: orbiting closely around star A, orbiting closely around star B, or orbiting distantly around both stars (and their mutual center of ...
1
vote
1answer
20 views

Why do some neutron stars become pulsars? [duplicate]

I suspect this may be an open problem in astronomy, but I have to ask anyway. There doesn't seem to be any large-scale difference in the formation of pulsars from the formation of "normal" neutron ...
8
votes
1answer
480 views

Do all orbiting bodies eventually collide?

If two celestial bodies are in orbit, will they always eventually collide if not acted upon by outside forces?
0
votes
1answer
35 views

Where can I find a catalog for stars within 450 light-years of Earth?

Where can I find a catalog for stars within 450 light-years of Earth? I'd prefer one that has approximated masses as well.
1
vote
2answers
48 views

What does Stephen Hawking mean by 'an infinite universe'?

In the recent $100m search for extra terrestrial life project project, Stephen Hawking is quoted in the following way: "We believe that life arose spontaneously on Earth," Hawking said at Monday's ...
1
vote
0answers
14 views

How can exoplanet moons be detected? [duplicate]

How can exoplanet moons be detected? Are there current methods to differentiate exoplanets with moons and exoplanets without moons? Or, are only the combined masses of the exoplanet and its moons ...
4
votes
1answer
26 views

Why do some artificial satellites decrease and increase in brightness multiple times?

I just observed a satellite almost directly above me travel for a few minutes while constantly dimming and then getting brighter. It did this for about 3 minutes until it faded out. I also observed a ...
2
votes
1answer
37 views

About the reference for equation of state

Well, I am a post graduate studying mathematics. Current I am working on the mathematical theory of star(not an expert thought). When I am making some assumption on the equation of state (for a star ...
-2
votes
1answer
24 views

What would Earthlike planets bigger than Earth with <10 m/s^2 gravity and complex life be like?

Large is bigger than Earth. Assuming that such planets exist (though I guess if such planets don't exist that would explain much of the Fermi paradox). Maybe some amount of iron is needed though, to ...
0
votes
1answer
24 views

If your near a black hole and your time is slowed down, would a supernova be observable to both you and someone outside of the blackhole's pull?

Let's say that Person A is on a planet orbiting a blackhole(Like the one from interstellar) and time is slowed for Person A. Person B is back home on Earth. Now let's say a supernova happens and it's ...
2
votes
2answers
28 views

Galaxy Cluster Temperature

I've read once in an article that the temperature of the medium between the galaxy superclusters is extremely high. What does that temperature really mean? particles' velocity? Why is that so? Is ...
3
votes
1answer
111 views

Are there any Stars we know don't have planets?

We have been looking for planets around other stars for a while (see related Are there any other Earth-like planets in the universe? ) and we are finding lots of planets, some of them are Earth like ...
6
votes
1answer
79 views

why does pluto have a high orbital inclination

Pluto has a high orbital inclination compared to the planets in our solar system. What has caused Pluto to have such a different orbit -- was it always like this, or did something happen to make it ...
-1
votes
0answers
15 views

What is the command to start star lab software [on hold]

I have installed starlab software. I need to know the command to start star lab.
0
votes
0answers
16 views

Linear motion in the equatorial frame

I would like to calculate how the RA/Dec changes when an object has an apparent linear motionin the equatorial sphere. For example, more or less what an artificial satellite would do in a circular ...
2
votes
3answers
102 views

During night on the Moon is there Earth light and Earth phases?

I realise that night time on the Moon is two weeks, however I am curious if during the night there, whether or not the Earth reflects light in similar manner to the Moon. On the one hand, I know it ...
3
votes
1answer
29 views

First time visit to dark sky stargazing site: what do I need?

Complete newbie here. I have an opportunity to visit one of the few designated dark sky sites here in Pennsylvania, Cherry Springs State Park. I plan on camping out over night, but I have never gone ...
1
vote
0answers
18 views

How to find the distance between two quasars

I want to calculate the distance between two quasars of which I know the angular position and the red shift. Let $Q_1=(\alpha_1,\delta_1, z_1)$ and $Q_2=(\alpha 2,\delta 2, z_2)$ and suppose $z_2 > ...
2
votes
2answers
67 views

Massive Nearby Stars

Is there a possibility that I will find records of stars with masses around 25-30 solar masses within 30 parsecs of solar system. If not, how far do I need to look?
6
votes
1answer
78 views

Pluto- Current theories regarding its geological nature?

The images of New Horizons from Pluto will take more a year to arrive from space, for the moment with have some compressed images as a preview. Nasa has advanced some information regarding the ...
0
votes
2answers
50 views

Calculating the mass of star

I am doing a project which requires that I have data for the mass of several stars. However, the data for mass of stars is obviously not readily available as it's really hard to calculate. In such a ...
4
votes
1answer
65 views

Speed of blast from supernova

How fast does the blast front of a supernova expand at? Is it close to the speed of light or is it less than a quarter of the speed of light?
1
vote
1answer
63 views

Can a supernova make a new star? [duplicate]

Today I was wondering with a friend about the birth of a star. So we know that stars are born from a nebula, but the residue of a dead star (like a supernova) is itself a nebula. So can a star be born ...
1
vote
0answers
37 views

Any freely available large stellar spectra catalog?

For a non-astronomy personal project I would like to have a large set of optical stellar spectra combined with absolute magnitude when available. I search for a dataset that contains 10k - 10M ...
1
vote
1answer
37 views

Has SETI data been used for astrophysics? How, or why not?

SETI collects alot of data from space, mostly radio. I wonder if this data has any astrophysics value other than SETI?
0
votes
0answers
15 views

How will the Breakthrough Initiatives affect other astronomy observations?

BACKGROUND The Breakthrough Initiatives is in the news because of a $100 million private donation for a SETI project. It doesn't seem to be for building any new observatory (but maybe for buying ...
1
vote
1answer
68 views

Can a galaxy splits into multiple galaxies?

Is there any naturally occurring event powerful enough that can cause a galaxy regardless of shape and size to divide itself into two or more smaller galaxies?
4
votes
1answer
81 views

Could an ejected “extra ice-giant” still be lurking in distant solar orbit?

BACKGROUND Hot Jupiters are thought to have migrated inwards, implying that another giant planet has been ejected in order to conserve the orbital momentum of those planetary systems. The number of ...
2
votes
1answer
75 views

Can we see Earth by looking into space?

It is known that spacetime is curved,so I am wandering to know if its possible to look into space and we see earth (light from earth long long ago). Did I understood spacetime correctly and if its ...
2
votes
1answer
319 views

Shall we say now that Pluto is “larger than Mercury” ?

http://pluto.jhuapl.edu/News-Center/News-Article.php?page=20150717-3 "Scientists working with NASA’s New Horizons spacecraft have observed Pluto’s atmosphere as far as 1,000 miles (1,600 kilometers) ...
0
votes
0answers
34 views

why do peple think the most energetic events in the universe are GRBs?

Recently people have found supermassive black hole binaries with very short orbital period. link They should be more energetic than GRBs when they merge, right? It seems people do not talk about ...
0
votes
0answers
17 views

How does the lack of magnetic field on Mars affect the possibility of using electricity there? [closed]

Thank you to all who spend time and energy reading this and using your brains. I am learning about electricity and magnetism and find that they are two phenomena of the same thing. What that is...? If ...
0
votes
1answer
35 views

Why do we observe spectral lines of specific energy?

The basis of my confusion is that atomic orbitals, even when described accurately by quantum numbers, have definite energies, meaning they represent energy eigenstates of the wave function. They're ...
1
vote
0answers
32 views

Is the Tombaugh Regio on Pluto visible from Earth?

Is the Tombaugh Regio on Pluto discernably visible from Earth ground based or Earth orbiting telescopes? And more generally, can surface features seen in Hubble images be matched with images from New ...
0
votes
0answers
17 views

Are lunar occultations visible to the naked eye?

The Moon occults a lot of stars. But are these events visible to the naked eye? Won't it be blinded out by the crescent even at its thinnest just before sunrise? Did ancient astronomers actually ...
1
vote
1answer
35 views

What is a “jumping trojan”? And what do their orbits look like?

I was googling Neptune's trojan companions and found on Wiki this claim about ~200 km diameter (316179) 2010 EN65: " the object is actually a jumping trojan, is jumping from the Lagrangian ...
3
votes
2answers
143 views

Does Pluto have impact craters?

I've heard from a lot of sources that Pluto doesn't seem to have any impact craters, but I see a few things that look like impact craters, highlighted in this picture: For comparison, here's ...
0
votes
1answer
56 views

How significant is a planet's density to the formation of life?

I'm doing some writing set on a fictional earthlike planet that for reasons needs to be substantially larger than Earth but can't have substantially higher gravity. I've been able to compromise with a ...
2
votes
3answers
148 views

How did our ancestors discover the Solar System?

I wonder, how did our ancestors discover the Solar System? They did not have any telescopes to see distant objects, right? Even a planet looks like a star from a distance. They discovered the ...
1
vote
1answer
53 views

Whats to be gained from the New Horizons mission once its beyond the Kuiper Belt?

Now that we have seen what Pluto has to offer and New Horizons is headed to the Kuiper Belt, is there anything we can gain from the mission in interstellar space after it travels beyond the Kuiper ...
0
votes
1answer
39 views

How do you determine which star, between two, is more luminous?

For example, if star 1 is 4x bigger than star 2 but both are the exact same temperature how do you determine which is more luminous?
2
votes
1answer
115 views

Real images (not “artist concept”) by NASA

Does NASA make publicly available real images of missions in an organized manner? What I mean is: Say I'm looking for the images taken by New Horizons - a simple list of the images in chronological ...
1
vote
1answer
15 views

Any tip on maintaining a log of celestial objects?

I am an amateur observer and Olympus 10x50 binocular is my tool. As I keep locating celestial objects (Planets, Stars etc), I would like to maintain a log of the observed objects. The purpose of the ...

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