1
vote
1answer
44 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
119 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 ...
2
votes
3answers
150 views

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
63 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
74 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
53 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
237 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 ...
2
votes
5answers
185 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
22 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
58 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 ...
4
votes
1answer
87 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
357 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
42 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
166 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
21 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
35 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
316 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
17 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
22 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
901 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 ...
0
votes
1answer
30 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 ...
2
votes
1answer
32 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?
6
votes
1answer
97 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 ...
3
votes
2answers
35 views

Globular cluster star density as a function of distance from the center

Context: I want to simulate globular clusters in a simple way, just to display the positions of stars. Assuming isotropy, what would be a reasonable model of the stellar number density as a function ...
5
votes
1answer
142 views

Wouldn't the rings of Saturn experience tidal effect?

The "Lord of the Rings" has more than 60 moons, some of which are larger than Mercury. My question is, wouldn't the ring, which is mostly comprised of rocks, experience tidal effect whenever a moon is ...
1
vote
1answer
32 views

Attraction to barycenter

If an object was a distance from a planet away that equaled the distance from the object to a moon of the said planet, would it be drawn into the direction of the barycenter as it is the common center ...
0
votes
1answer
54 views

How come, in our lifetime, we will see the first stars which ever formed?

Isn't it an unlikely coincidence that we live in such special times, that we will have observatories (JWST) that see all the way back to the first starlight in the universe? Are we dreaming, and is it ...
0
votes
2answers
60 views

The Fermi paradox

Ok so I was reading about the Fermi paradox, assuming life will form and thrive where possible as soon as possible and there is a very probable chance many other earths formed would they have started ...
1
vote
3answers
202 views

Mini black holes, a possible result of the LHC experiment at CERN

A scientist at CERN LHC (Large Hadron Collider) was asked during an interview about the possible results and consequences of operating the LHC at full power of collision in the near future, one of the ...
0
votes
1answer
26 views

Exoplanets and relativity [duplicate]

Ok, so I have read about how exoplanets are found using all sorts of genius methods. I also understand the further an obect in a telescope is the further into the past I am looking. So given that ...
3
votes
1answer
80 views

Is radiation from neutron stars delayed by time dilation?

I understand a neutron star to be the densest stuff that can exist without becoming a black hole, the densest thing which directly gives off radiation we can detect. At the event horizon of a black ...
0
votes
3answers
122 views

“Up” and “down” in Space [closed]

From my understanding, "up" and "down" in space is going towards (down) an object's gravitational pull or (up) which is going away from it. I get confused with this explanation, and I believe simply ...
2
votes
1answer
33 views

Standardized “constellation” regions?

The current system of constellations is historical and has kind of arbitrary boundaries. This has a number of obvious downsides: Difficult to define boundaries need complex tables to express Each ...
1
vote
1answer
23 views

What is a typical value for core-to-star efficiency?

I was reading Unfolding the Laws of Star Formation: The Density Distribution of Molecular Clouds by Kainulainen et al., which discusses star formation rates and efficiencies. One variable used is ...
0
votes
1answer
90 views

What supernova has created the iron currently found in Earth core?

Iron is generated by stars in a certain part of their life cycle. Earth contains a lot of iron inside, however it is clear that this iron could have not been generated in a star in close proximity. If ...
3
votes
3answers
230 views

What happens to galaxies when they die?

Stars explode when they die and blast heavy elements into space. Do galaxies do the same thing?
5
votes
3answers
187 views

How are rogue planets discovered?

Planets are usually found by observing a star and waiting for the light level to drop when a planet passes in front of it, but what about rogue planets that don't have host stars?
1
vote
1answer
29 views

Difference in redshift between 2 interacting galaxies

I have a galaxy 'A', say at redshift 1. Let's suppose this galaxy has no peculiar velocity. What would be the redshift of another galaxy 'B', that has a radial velocity of 500 km/s, relative to A? ...
0
votes
1answer
83 views

Finding Latitude and Longitude of a person or of where a picture was taken

this is my first post on the Astronomy stack exchange site. Please let me know how this question is based on y'all's generally accepted criteria for a good question as well as possible improvements. ...
1
vote
1answer
22 views

Occurence of Venusian transits

As transits of Venus come in pairs each seperated by 8 years, wouldn't that imply an accurate ratio between earths and Venus' revolution period? I've found the ratio to be about 0.681. I presume one ...
-1
votes
1answer
73 views

Evidence that galaxies are made of billions of stars?

What is the evidence that galaxies are made of billions of stars? Even faint galaxies? Can spectral analysis distinguish galaxies from individual stars?
6
votes
2answers
1k views

Does the Moon's magnetic field affect Earth's magnetic field?

I wanted to ask a question; it's simple but I cannot find any possible and perfect solution. Earth has poles, North and South. By which we can get directions using a compass or a needle compass, but ...
0
votes
0answers
14 views

If conjuncting planets are 1/3° apart (geocentric) at 15° elongation how low could the elongation at closest approach be?

Does anyone even have a rough idea? I don't know which pairs of planets can appear close for longer without changing elongation too slow like Mars does when behind the Sun.
0
votes
1answer
102 views

Has the sun become way brighter the last years?

Up to last year, I never got blinded by the sun in everyday situations (e.g. running towards it), at no time of the year I was. But since last christmas, it occured to me more often that I cannot ...
2
votes
3answers
120 views

Which is really larger, Big Dipper or Small Dipper, in 3D

If we take the convex hull of the 3D coordinates of the stars in Ursa Major and Ursa Minor: which hull has larger volume? This is meant semi-humorous but we might also learn some interesting points ...
3
votes
1answer
27 views

What happens to the Gas Pressure when working out the Eddington Luminosity?

I am looking at how the Eddington Luminosity is derived and I do no understand why we only care about $P_{rad}$? When working out $L_{Edd}$ you take the ratio between $dP_{rad}/dr$ and ...
2
votes
4answers
566 views

Which is more rare: Lunar eclipse or Solar eclipse?

Which is more rare: Lunar eclipse or Solar eclipse? Please explain why either one is more rare than the other. Thank you in advance for your inputs.
1
vote
1answer
114 views

Stars in the sky

Are the stars we can see with the naked eye in the night sky only from our Milky Way galaxy or can we see stars from Andromeda? I am aware we can see other celestial objects like nebulas and the ...
-1
votes
1answer
27 views

Two body transient solution

In the two body problem, if each body is given an initial condition as a momentum vector, what is the transient part of the solution as it settles into the steady state orbit?
5
votes
1answer
733 views

How was the Earth-Sun distance originally calculated?

AFAIK it was possible long before the first interplanetary probes. Who did it?

15 30 50 per page