1
vote
0answers
9 views

Roll, Pitch and Yaw of Orbital Planes

I a have been reading about celestial mechanics and particularly about planetary orbits. I understand that a planet's orbit can be tilted (pitched) with respect to the Earth's ecliptic and that it ...
0
votes
1answer
14 views

Finding the suns position in the sky anywhere at any time

What am I looking for? from any point Latitude, Longitude and date D I want to know where the sun is in the sky at any given time anywhere on our planet. I even don't know what the outcome will be ...
3
votes
4answers
113 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 ...
4
votes
4answers
141 views

Image sets for testing stacking algorithms?

I am looking for sets of astronomical images for testing different kinds of stacking algorithms. The idea is simple: if one has $N$ images of the same object, the signal-to-noise ratio of the ...
1
vote
1answer
77 views

Can the Sun become a big ball of gold atoms?

The atoms inside the core of sun are continuously fusing and forming other atoms. Can this continuous fusing make gold atoms?
2
votes
1answer
18 views

What causes the aurora of other planets to have different colors?

All I could come up with is it depends on the atmospheric composition of the planet as they will interact with the charged solar particles which might be true but is there is there a definite reason ...
2
votes
1answer
75 views

What's to be gained from the New Horizons mission once it's 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 ...
-1
votes
0answers
33 views

Why does Mercury have some cold temperatures?

We all know Mercury is very close to the Sun, so why does Mercury have some cold temperatures? In contrast, the chilly night side can get as cold as minus 279 F (minus 173 C). From here.
1
vote
1answer
41 views

Sun's apparent motion above the arctic circle during summer solstice

I'm having difficulty with an apparent contradiction about the sun's motion during the summer solstice above the arctic circle. The YouTube video The North Pole Entire Summer of never ending sun ...
4
votes
1answer
70 views

What's the distribution curve for meteor sightings?

I know that meteor showers have a "peak" observation time. What does the distribution in time look like? Is one side of the peak steeper/shallower or longer/shorter than the other side, and if so, ...
1
vote
1answer
22 views

stellar metallicity

I saw a talk recently mentioning that another factor that may determine a star's metallicity (besides age) may be how far from the center of its "birth cluster" it is when the short lived hot central ...
0
votes
1answer
24 views

What is a Seyfert galaxy?

I know Seyfert galaxies are types of active galaxies, but I do not understand what separates them from other types of active galaxies. Are they brighter/not as bright as other types of active ...
8
votes
2answers
2k views

Is it possible to witness a star's death?

Given that the stars' distances to Earth are measured in light-years (for example, Sirius is 8.6 light-years away from Earth), what we are seeing as Sirius now is actually its state 8.6 years ago, ...
4
votes
0answers
26 views

Were parts of the Universe deflating during Inflation?

I was reading about the history of the early universe in Carroll & Ostlie and specifically looking at Inflation, which, as I understand, occurred because our [observable] part of the universe ...
1
vote
1answer
21 views

Real-time position of a distant celestial body

How might it be possible to determine (via some specific online empemeris or via some well-understood algorithm) the current position of some distant celestial body (e.g. Betelgeuse)?
1
vote
2answers
62 views

How/where to check where the Sun is (constellation)?

I would like to check in which constellation the Sun was in at some time in the past, any recommendations how to do that?
3
votes
1answer
22 views

Is the Astronomy community still concerned about the lumpyness of matter distribution in the universe?

A decade or so ago, when I was still a science undergrad, one of the open questions in astrophysics was to explain the uneven distribution of galaxies in the observable universe. That is, why did the ...
-3
votes
0answers
38 views

What if the earth stopped rotating and revolving at the same time?

What will happen to us are we going to move in a tangential direction with earth axis of rotation ?
0
votes
0answers
32 views

Is the speed of a black holes gravity faster than light?

If light cannot escape a black hole because of it immense gravitational pull, wouldn't that mean that everything that the black hole consumes be sucked in faster than light?
0
votes
1answer
20 views

Road map for a faster spaceship [on hold]

New Horizons, speediest yet, is currently running at about 15 km/sec relative to the sun. What is the roadmap for future ? How is it possible to reach much faster speeds ?
2
votes
1answer
165 views

The dark side of the moon

I encountered this statement that the dark side of the moon is hidden from our sights. Could someone please explain?
4
votes
2answers
88 views

Why does radio astronomy offer higher resolution images than optical?

According to this lecture,"Radio astronomy has several advantages over optical astronomy...We can make the highest resolution images, and see things happening on the smallest scales." Why is this? If ...
0
votes
1answer
15 views

How to specify SM libraries for MOOG

I am running MOOG on OS X Yosemite and with $MOOG running the abfind driver I can force fit elemental abundances with an appropriate input line list and model ...
0
votes
1answer
43 views

When will the next summer solstice and a full moon coincide? What day?

What day will the summer solstice and full moon coincide? As far as I know the next time will be in 2016. I would like to know what day.
3
votes
3answers
1k views

Does a black hole become a normal star again?

Stars which satisfy the Chandrasekhar limit can become a black hole. What happens to star after it becomes a black hole? Does it regain its status of star?
1
vote
2answers
70 views

What is faster than a supernova explosion?

Is a supernova explosion really fast or is it just fast, metaphorically speaking? Can you cite the fastest known phenomenon in astronomy (neutron stars, pulsars) besides supernovae in terms of ...
2
votes
1answer
27 views

International Space Station

Recently, I have been going out to observe the ISS when it is within sight of my location. I have noticed that the ISS, based on the time that I have to observe the space station during any given ...
2
votes
2answers
54 views

Do most planetary systems have fewer planets than the solar system?

It is my impression that most planetary systems have, at most, three to four planets. Is that real? Or is it just that we lack the ability to detect most planets?
0
votes
1answer
41 views

Can things move faster than light inside the event horizon of a black hole?

Black Holes are regions of space where things get weird [Citation Needed]. Past the event horizon of a black hole, any moving particle instantaneously experiences a gravitational acceleration towards ...
3
votes
2answers
63 views

Gravitational lensing in Newtonian physics

Famously, when Eddington attempted to measure gravitational lensing during the Eclipse, it was the measured magnitude of the lensing that gave gravity [pun, obviously, intended] to General Relativity ...
5
votes
2answers
139 views

Likelihood of a stable system with a dwarf planet's orbit inside that of a gas giant

I keep thinking of various planetary system configurations, and would like to know: What are the fundamental references based on Monte Carlo long-term simulation of planetary systems' evolution that ...
1
vote
1answer
33 views

Why are there no Oe or Ae stars?

The unique characteristics of Be stars are mainly because of their circumstellar discs. I wonder what makes Be stars special that only they have unique characteristics? Which kind of stars have discs ...
0
votes
2answers
25 views

Simulating location of the moon

I'm researching high altitude photography and want to know a schedule for taking pictures of the moon. Preferably I want a picture of the (full) moon on the horizon. How would I go about scheduling ...
1
vote
3answers
1k views

How much magnification is needed to see planets of solar system?

I have a 3inch Newtonian reflector telescope with 300 mm focal length. I can use highest magnification of 75x using a 4mm eyepiece. But in 75x I can't see details of Jupiter what was expected. Instead ...
2
votes
1answer
38 views

Does tidal heating imply orbit degradation?

What compensate the energy loss in tidal heating? Is it orbital decay?
4
votes
0answers
63 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 ...
17
votes
4answers
1k views

Where does the Solar System end?

This is a question I've heard many times in the past, and a quick search of the site says it hasn't been asked here, so I figured I might as well ask (and answer) it. I know that it is rare for ...
1
vote
1answer
23 views

how many bodies can i see by 90x telescope

I am a 9th class student so Im a begginer of telescope hence please help me. Please answer my following question. How many bodies can I see by 90x telescope? 2) How will I know that when and where I ...
3
votes
1answer
38 views

Ultra Low Cost Telescope Project

A few years or so ago there was a project that distributed small very low cost telescopes (perhaps around US$20). What was the name of (and links to) that project?
0
votes
0answers
29 views

Could the warp drive be possible? [on hold]

Many people say that we'll never reach the speed of light, but if someday we constructed a warp drive, would it be possible to reach that speed? If not, what is maximum velocity we could reach with ...
-2
votes
0answers
75 views
0
votes
1answer
34 views

Relationship between temperature and HRD [on hold]

If the temperature of a star is increased, and the size of the star is not modified, the point which represent the star in the HRD moves: Upwards to the right Upwards to the left Downwards to the ...
0
votes
0answers
17 views

Units of angular power spectrum

I am not sure whether this question might be better suited for crossvalidated or stackoverflow, but I will give it a try here: I have a map of the full sky in in the healpix format, units are $\rm ...
2
votes
4answers
2k views

Why did the moon abruptly change positions in the sky?

Three or four weeks ago I was outside showing my neighbors how cool the moon was through a 'backyard' telescope in broad daylight (~8PM PDT). It was 3/4 of the way across the sky (setting behind the ...
-1
votes
0answers
19 views

Stellar velocity dispersion (bulge)

Can I calculate the stellar velocity dispersion from the modified Hubble law? Actually I have seen that there is formula $$\text{Velocity Dispersion}^2 \equiv \frac{\int (\sigma^2 + V^2) I ...
1
vote
1answer
21 views

IAU Dwarf planet definition Point 2.b - is not a satellite

I am a bit confused with point 2.d of the IAU's resolution on dwarf planets. (2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun (b) has sufficient mass for its ...
1
vote
1answer
48 views

How long will it take to reach the closest earth like planet

Using the engines today how long will take humanity to reach earth like planets?
1
vote
1answer
23 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 ...
2
votes
1answer
59 views

Why are there no more images revealed by New Horizon?

Since a few days after the flyby there are no more images published on the NASA page. Why is NASA waiting to publish any more images for some reason? Or is there something happened to New Horizon?
1
vote
1answer
37 views

What is the largest possible size for a brown dwarf?

What is the largest possible size for a brown dwarf before it has enough mass, capable of sustained fusion, thus becoming a star?

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