0
votes
0answers
2 views

How well do planetary orbits fit with Johannes Kepler's in- & circumscribed Platonic solids?

In Mysterium Cosmographicum (1596) Johannes Kepler proposed that the relative distances between the orbits of the six ancient planets (six because heliocentrism had recently added Earth as one of the ...
2
votes
2answers
66 views

How to calculate position of an unknown star knowing positions of some other stars from an image?

Suppose I know the coordinates (right ascension and declination) of the stars marked with red. How should I calculate the coordinates of an unknown star, marked with yellow? Searching over the web, ...
2
votes
0answers
22 views

Can there be an object with planetary discriminant between Ceres and Neptune?

The planetary discriminant is a measure of how dominant a body is within its region of the solar system. For (true) planets, it is >10000 and for dwarf planets it is <1. See this answer for more ...
0
votes
0answers
12 views

Capturing Ceres

Would it be possible to slightly change the Ceres trajectory to make it ending up orbiting the earth without messing up the solar system ? Which energy would be required and how long would it takes ? ...
1
vote
1answer
3k views

Why is the Solar Helical (Vortex) model wrong?

Could someone give a lay description of why the Solar System's depiction of motion as a vortex is wrong? ref: Youtube video The helical model - our solar system is a vortex Please don't take for ...
4
votes
2answers
112 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 ...
0
votes
0answers
11 views

Do the planetary ring lasts? [duplicate]

Almost all gas giants in our solar system are observed to have a planetary ring comprises of ice, dust and rocks. My question is do these rings obediently sticks around their foster parent until our ...
5
votes
3answers
227 views

Why are all quasars so far away?

Why are all quasars so far away? If the universe is homogeneous, we could expect to have a homogeneous distribution of quasars, but all of then seem to be far away from Earth. Why is that?
1
vote
0answers
11 views

Why don't all space junks burn up? [migrated]

Man-made satellites have to use boosters to accelerate to maintain orbit around the Earth, space debris and old satellites with depleted booster should be pulled by either Earth's gravity or slowed by ...
0
votes
0answers
12 views

What are the analysis steps in taking raw data from Kepler to a planetary system determination

I wish to get a concise list of the analysis steps required to take raw light data from a Kepler data set of a star through the steps needed to get to an analytical determination of the existence of a ...
0
votes
0answers
11 views

Chances of man-made satellite colliding with space debris [migrated]

Firstly, has a man-made satellite, or indeed any spacecraft, ever collided with space debris and been destroyed? What are the chances of this happening? (I imagine very slim, but how slim?) And do we ...
5
votes
2answers
43 views

Why aren't secondary mirrors offset to get rid of diffraction spikes due to the support vanes?

Some kind of ellipsoidal shape mirror could reflect to a secondary mirror which is not in the way of the infalling light. Two advantages are immediately obvious. The primary mirror would not be partly ...
0
votes
1answer
32 views

Asteroids in langrangian Points 4 & 5

There are Asteroids "trapped" in Jupiters Langrange points 4 and 5 called trojans and greeks. Are there any asteroids in the earths L4 and L5? Have we seen asteroids in Lagrange points of the earth ...
-3
votes
1answer
49 views

How much time comet is within the Earth's orbit? [on hold]

Comet on the parabola orbit flies by Sun. I would like to know what is comet's full energy? What is its distance from Sun at perihelion?
-2
votes
0answers
22 views

How much time runs from derailing to the fall of the satellite and its true anomaly at the fall? [on hold]

Planet with a radius R and mass that goes around on the elliptical orbit with a semi-minor axis a and eccentricity e. Its speed of the fall equls v0. What is full of energy at the satellite at ...
-1
votes
0answers
16 views

Retrograde momevent and Distance of Saturn from the Sun and its Sidereal Period [on hold]

The numbers marked a reference position of the planet at the beginning of the relevant month. Elongation Saturn at stationary point (jam) is 109 degrees. I wonder how much elapses between two ...
-3
votes
0answers
19 views

To what extent we should just before the collision with the rock change the speed of the probe that it would be relative to the rock equal to 0? [on hold]

We are having a satellite lauched from the Earth to reach the roch on a hyperbolic orbit around the Sun. The both have the opposite velocity vectors. I wonder how long does it take to reach the rock ...
1
vote
1answer
32 views

How to calculate full (mechanical) energy on the hyperbolic orbit?

For example, for a comet that travels on the hyperbolic orbit around the sun.
0
votes
2answers
112 views

Putting mass-luminosity relation and Hertzsprung-Russel diagrams together leads us to a mass-age relation; so how do stars lose their mass over time?

I think that the title is completely clear, but here's an expansion: I was just reading about Mass-luminosity relation that says massive stars are more luminous than tiny ones. Well, let's talk about ...
0
votes
3answers
110 views
+50

Longest and shortest wavelength

What is the longest and what is the shortest wavelength of light? How fast would a light-emitting object have to recede in order to shift the frequency of light to increase the wavelength from the ...
-2
votes
1answer
56 views

Michigan's Pole Star

Unfortunately, I'm not any good at figuring these things out myself so hope for help here. If the (true) north pole were over the Keweenaw Peninsula of Northern Michigan, what would the North Star be; ...
2
votes
3answers
72 views

What must/do astronomers reveal beyond their academic papers?

Academic papers often make claims about observational data and results from computations. The papers only refer to names of data sources (such as an observatory) and of mathematical methods without ...
1
vote
1answer
36 views

How to deal with shifting CCD bias (zero exposure) levels?

The median values of the bias frames coming from our teaching telescope shift up or down with each capture. For example: ...
4
votes
3answers
225 views

Why do dark objects look white from a distance? (Moon, Ceres, but not Earth!)

What makes the Moon shine white in the sky, although it seems to be as dark as asphalt? Earth's average albedo is 3 and 4 times that of the Moon and Ceres respectively (0.37 vs 0.12 and 0.09). But ...
0
votes
5answers
128 views

Can the Milky Way be seen with the naked eye? Does this apply to any galaxy? If yes, then how and when?

I have seen different pictures in a different community to showcasing the Milky Way. I can never tell whether it's edited or it's the real picture. Actually, I can never see any galaxy as such by with ...
1
vote
0answers
19 views

What is the reason for the dispute over the variation of core mass with heavy metal abundance?

In Metal-Poor Stars IV: The Evolution of Red Giants, Rood writes The differences in the results of these papers are large enough to introduce appreciable uncertainties into the study of the ...
0
votes
2answers
52 views

How was all the matter curled up inside a singularity during big bang ?

If the singularity had infinite mass, temperature and density, then it should curve space and time but there was no space-time before big bang. So where did the singularity come to existence without ...
10
votes
5answers
2k views

Is Pluto still a dwarf planet?

Recent news seem to suggest that astronomers are arguing about whether Pluto should become a planet again. However, I cannot find an official source for this. Is this actually true?
4
votes
1answer
86 views

What study profiles could land me the job of astronomer?

I realize there are very few to none universities that offer direct specialization of astronomy. If I aspired to be make astronomy my career choice, I'd likely have to pick something like physics and ...
4
votes
3answers
334 views

I'd like to become an astronomer. What experience do I need? [closed]

I think I'd like to become an astronomer. What degrees and training/experience do I need to become one? I've heard I should take science and mathematics, but I don't know which specific courses I ...
0
votes
1answer
40 views

Where can I find the image of MY Camelopardalis?

In this news article, it says The image captured by the telescope at the Calar Alto Observatory in southern Spain, reveal the physical properties of each of the stars including temperature and ...
3
votes
2answers
147 views

How much mass will the Sun have when it becomes a white dwarf?

In 4 billion years, when our Sun sheds all of its outer gas layers and turns into a white dwarf, how much mass will the white dwarf have compared to what the sun has today? Will the planets still ...
0
votes
0answers
18 views

coordinates in ICRF

The International Celestial Reference Frame (ICRF) is defined based on distant quasars and the origin is the barycentre of the Solar system. So, how can we measure the coordinates (\alpha, \delta) of ...
0
votes
1answer
33 views

why are solar telescopes built on lakes? the site differnece between a solar and an optical telescope

According to the wikipedia page big bear, water can cool the observatory. Big bear is in the southern California. It is better to build it on a cold high mountain with stable and clear atmosphere? ...
1
vote
1answer
105 views

What are the azimuths of the planets' orbits?

I am creating a virtual solar system model and I want it to be as realistic as possible (e.g. orbits are ellipses, not circles, and orbits are oriented correctly, not all coplanar). In order for me ...
4
votes
1answer
134 views

Given a date obtain latitude and longitude where is the sun zenith

Searching is easy to find terminator line (frontier between day and night) or the position of the sun in the sky given a position on the earth and a time; but I can't find how to obtain where is the ...
0
votes
1answer
31 views

Types of Exoplanets

We discover vastly more exoplanets, that are gas giants that orbit their parent star very closely, than small terrestrial planets that are more distant to their sun. Could this be due to the methods ...
9
votes
2answers
294 views

Is it possible to break apart a neutron star?

I was inspired by this question on Physics, as well as this question right here on Astronomy. Neutron stars are tightly bound together as neutron degenerate matter. They're very massive and have a ...
0
votes
0answers
15 views

How is the age of a star on the Henyey track calculated?

I was reading Stellar Evolution in Early Phases of Gravitational Contraction, by Chushiro Henyey, where he writes, If $L \propto R^{-\alpha}$ along the path, the age of a star from the time when ...
0
votes
1answer
31 views

For how many bodies can there be a stable orbit with no very heavy central body?

The question is a bit vague, but let me explain: Take for example 2 bodies of the same mass. They can orbit around their centre of mass/gravity. Is something like this possible with multiple ...
0
votes
1answer
16 views

Probability of finding life-supporting exoplanets

We've found over a thousand exoplanets by now, but how many of them could support life? What percentage of newly found planets are potentially life-harbouring? Or haven't we found any exoplanets that ...
7
votes
2answers
843 views

How does moonrise/moonset azimuth vary with time?

In my tenacious attempts to observe moonrise (surprisingly difficult in a poor weather heavily urbanized hilly area with frequent bad smog, with busy work schedule and a bicycle) I was frequently ...
-1
votes
0answers
10 views

How would time travel work with a man made wormhole, with one side of it sent on a rocket at light speed and then returned to Earth? [closed]

I just watched an episode of the History channel series The Universe: Collection, this particular episode was focused on time travel. One of the theories mentioned is that a man made wormhole could be ...
0
votes
1answer
24 views

Sunsets: Mars/Earth

I understand why our sky is blue and turns red when the sun sets or rises. I know why the sky on mars is red, but why does it turn blue during sunsets and rises? Shouldn't this actually not work due ...
0
votes
1answer
21 views

Circumstances that would make it impossible to predict a large metorite strike? [closed]

Under what circumstances would it be impossible to observe a large meteorite on collision course with Earth, and thus to do anything to prevent or mitigate the consequences of the impact?
1
vote
0answers
25 views

Milky Way stellar number density : is the stated equation in this paper incorrect?

The paper is : http://www.astro.washington.edu/users/ivezic/Publications/tomographyI.pdf The equation is equation #23 in the paper. It's a model for the density of stars in the Milky Way's disk. It ...
0
votes
1answer
49 views

Planets orbiting Alpha Centauri

I read that a few years ago some planets were discovered orbiting Alpha Centauri. Has there been any more information since then concerning the possibility of life there? This is the closest star ...
2
votes
1answer
30 views

How are boulders formed on asteroids?

For example: Are they soft landed meteorites? Or do they form from melted material during a violent impact? Or are they the result of some kind of erosion process?
5
votes
1answer
82 views

How can we tell the difference between matter and antimatter by observation in space?

I just was wondering and searching on the internet with little luck in the topic. On Antimatter Wiki they tell the observable universe is built up by matter. I read antimatter can be detected in ...
2
votes
1answer
86 views

Is there a general term for epicycles, deferents, and eccentrics in Ptolemaic astronomy?

According to Ptolemy's (c. 150 CE) account of the motions of planets, planets moved in circular paths ("epicycles") around center points that in turn moved around the center of the earth along a path ...

15 30 50 per page