1
vote
1answer
12 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
15 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 ...
-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.
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
22 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)?
-3
votes
0answers
39 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
33 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
25 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 ...
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 ...
1
vote
1answer
23 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 ...
1
vote
1answer
79 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
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?
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?
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 ...
2
votes
1answer
28 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 ...
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
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 ...
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, ...
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
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
38 views

Does tidal heating imply orbit degradation?

What compensate the energy loss in tidal heating? Is it orbital decay?
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 ...
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 ...
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
0answers
75 views

If the Sun became a black hole, would it swallow our entire Solar system?

If the Sun became a black hole, would it destroy all the planets?
-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
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
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
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?
0
votes
0answers
40 views

Star like light moving in the sky, what could it be?

I was camping this weekend away from the city, so my friends and I decided to spend one of the nights watching the sky, since it's impossible to see anything around where we live. After a little ...
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
28 views

how to assess a periodical signal?

After folding a light curve, we may get some kind of shape. How to tell whether there is a real periodical signal quantifiably? The fluctuation may be small, and the folded shape may not be perfect. ...
5
votes
2answers
537 views

How is a non-rotating black hole created

How are non-rotating black holes formed? I guess that non-rotating black holes are formed from non-rotating stars but I couldn't find any proof that such a star exists on the internet. If this is ...
2
votes
1answer
58 views

What is the highest recorded temperature in space

What is the highest recorded temperature in space? I'm not asking about Planck temperature that is a fraction of a second before the Big Bang. I'm asking about the temperature that has been recorded ...
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 ...
0
votes
0answers
21 views

Can the explosion of a supernova destroy the Earth? [duplicate]

If there anywhere in near space a supernova that can destroy Earth? Not by the gamma-ray, but literally by supernova explosion itself?
0
votes
0answers
25 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 ...
2
votes
2answers
94 views

Can I measure the moon's gravity?

Since I learned about Newton's gravity law, I wonder if I can measure the moon's gravity using (almost) no special equipment. The best I could come up with is a pendulum, which is in a resting ...
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 ...
1
vote
2answers
44 views

L4 and L5 stability

For what I know, L4 and L5 are high points. Although, they are stable points. Why? I thought it was the same being a high point and being a unstable point. If I'm off-topic, please let me know where ...
1
vote
1answer
45 views

How is the heat production inside moons compliant with Conservation of Energy?

A Nova episode said that during stages of some moons' elliptical orbits, the moon is stretched, and friction causes the inside of the moon to heat up. I do not understand how this is compliant with ...
-1
votes
1answer
53 views

Which force makes planets to continuously revolve around their parent star?

We know that planets revolve around their parent star (or specifically Barycenter), they maintain a specific speed of revolution so that they don't end up smashing into their planet star. Which force ...
3
votes
1answer
81 views

What if our galaxy didn't have a SMBH?

From my understanding, it is believed that almost every big galaxy and especially spiral galaxies have supermassive black holes (SMBH's) at the center. Also, from what I've read, a SMBH isn't required ...
2
votes
1answer
32 views

What measure should I use to help optimise the design of a telescope in a cubesat?

I have started a project in Melbourne, Australia called nanosat eye in the sky to put a telescope in a cubesat and put it in LEO. The idea is then to add the telescope to itelescope. I need to learn ...
-2
votes
1answer
24 views

Radial Density Profile Equation

The Virgo Galaxy Cluster has a mass of $10^{14} M_{\odot}$ and its centre is $16Mpc$ from Earth. The large elliptical galaxy $M87$ lies at the centre of the Virgo cluster. $M87$ has a supermassive ...
1
vote
1answer
27 views

Meteors made of differing substances. Will they all burn up?

If an object enters Earth's atmosphere, what determines whether it burns up or not? Example A feather is released from a space-ship 30,000 km away from Earth and falls under the influence of Earth's ...
1
vote
1answer
20 views

Elemental abundances in the crust of exoplanets and accessibility to them

Suppose I am orbiting a rocky planet (density = 4.4 g/cm3) two-thirds the mass of Mars in the Habitable Zone of Gliese 251. This planet has a thin atmosphere, presumably from out-gassing, still has ...
1
vote
1answer
99 views

What is the largest hydrogen-burning star?

I am wondering what is the largest known core hydrogen-burning star? A look at the list of largest known stars on Wikipedia seems to indicate VV Cephei B (at the bottom of the list), but I would like ...

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