All Questions

0
votes
0answers
9 views

Are there any kinds of binary pairings that haven't been discovered yet?

There are lots of possible objects. For simplicity's sake (i.e. to hide my ignorance) lets assume momentarily that there are only black holes, neutron stars, white dwarfs, brown dwarfs, red giants, ...
3
votes
1answer
52 views

What's the reason that we have different quantities of days each month?

It always was interesting for me to understand the answer for the question: What's the reason that we have different quantities of days each month? If the month is fixed on the time that the moon ...
1
vote
1answer
15 views

How to separate binary and optical stellar pairs?

I have list of stellar pairs from The Washington Double Star Catalog (WDS), i.e. I have next parameters: angular separations position angles stellar magnitudes of both components Additionally I have ...
1
vote
3answers
70 views

Is space a thing?

Based on my extent of knowledge relating to astrophysics, I once thought space is a thing, which can be twisted a long side with Time regarding masses of objects(According to relativity theory). But ...
0
votes
1answer
28 views

What could possibly save an atmosphere other than a magnetic field? Why can't a magnetic field save the atmosphere in certain cases?

Similar question here. We know as a fact that the magnetic field protects planets from Solar Wind, a damaging, continuous, atmosphere-stripping wind of charged ions. Thus, a magnetic field protected ...
2
votes
1answer
41 views

Could there be additional Neptunian satellites between Larissa and Hippocamp?

Plotting the moons of Neptune in terms of semimajor axis and eccentricity using the values given on the Wikipedia page for the moons of Neptune, there appears to be a fairly large gap between the ...
1
vote
0answers
55 views

Is the water on Mars drinkable? [on hold]

Could water from Mars be fresh enough to drink? Could one run the water through a home water filter? I understand when water is frozen the salt is ejected as brine so would newly formed snow or ice be ...
2
votes
0answers
50 views

Is gravitational lensing a good way to search for negative mass?

Is it possible to verify negative mass with gravitational lensing? The following video proposes an idea that galaxies are surrounded by negative mass: https://youtu.be/MZtS7cBMIc4 Could this be ...
-1
votes
1answer
69 views

What would happen if a star went supernova inside a supermassive black hole?

A black hole swallows a star. The star remains intact. Then goes supernova. What would happen to the star? Could we detect this event?
4
votes
1answer
42 views

What do the months and hours mean in Tomas Filsinger's Map of The Universe

I have had one of these in my room for decades: I don't have the booklet that seems to usually come with it, can someone explain to me what the months (with days below it) and hours mean? I imagine ...
1
vote
1answer
38 views

Determining the shape of ʻOumuamua via stellar occultation

As far as I know, our current knowledge regarding the exact shape and size of ʻOumuamua is based on the analysis of its light curve and the assumption that it has a uniform albedo. ʻOumuamua is very ...
7
votes
3answers
98 views

How would rainbows appear on other planets?

Are other planets capable of producing rainbows? How would those rainbows appear? Can rain, clouds or ice from elements other than water produce rainbows? Related: https://space.stackexchange.com/...
1
vote
0answers
39 views

Could you tell me this constellation name? [on hold]

Hi Everyone please check this pictures could you tell me this constellation name ?
4
votes
1answer
57 views

Roche Zone of a black hole vs Roche Zone of Neutron Star

Suppose a very unusually small back hole with the mass of about, lets say, 1.5 solar masses(hawking radiation should destroy a lot of mass let's assume). It thus would have a Roche limit smaller than ...
0
votes
3answers
122 views

the movement of the moon

I was in Cuba from January 15th to the 22nd this year and there was a quarter moon. If I use a compass to explain the orientation of the quarter moon, it started in the north position around 4 pm. By ...
2
votes
1answer
50 views

Are there known centaurs which orbit between Jupiter and Saturn without crossing their orbits?

According to Centaur minor planet Centaurs are small Solar System bodies with a semi-major axis between those of the outer planets. They generally have unstable orbits because they cross or have ...
5
votes
0answers
55 views

Who was the first to realize that the Earth is surrounded by vacuum? [on hold]

My question isn't about the arrangement of planets in space (geocentrism / heliocentrism), nor the understanding of the whole universe (we are in a galaxy, there are galaxies etc). My question is: who ...
2
votes
2answers
101 views

Do interstellar asteroids decelerate and eventually stop?

I do wonder, do interstellar asteroids eventually stop at one point in space after they gradually decelerate (or) even do they decelerate? Though there is no air like on earth and thus asteroids ...
3
votes
1answer
87 views

What's going on in this photo of Halley's comet's tail?

When researching for this answer I was looking at Space.com's 2011 article Photos of Halley's Comet Through History I saw the image below, and read the caption. Halley's Comet in 1910 ...
4
votes
1answer
48 views

Halley's Comet current location in sky and visibility?

I am an amateur in astronomy, but recently I wonder if it is possible to see (in a photo, maybe, if not in a telescope) Halley's Comet when its not close to earth. If there is such photo, how I can ...
3
votes
1answer
61 views

What I can observe with a 80/900 refractor telescope? What can I study?

Recently I bought a telescope after a very good conversation with an astronomer friend of mine. The main goal is to see planets. However, Mars is so difficult and is far to find it in opposition. I ...
3
votes
1answer
50 views

Which is the farthest distance a particular distant known- identified object from the asteroid belt can get from the sun?

According to Space facts The Asteroid Belt is located in an area of space between the orbits of Mars and Jupiter. That places it between 2.2 and 3.2 astronomical units (AU) from the Sun But ...
0
votes
1answer
83 views

What is so special about the Ultima Thule passed by New Horizon spacecraft?

I read that the New Horizon spacecraft passed by the Ultima Thule. I also got to know that it is a flat, snowman-shaped rock. What is so special about it?
3
votes
2answers
47 views

How to calculate the argument of perihelion for exoplanets with incomplete orbital elements?

I'm trying to simulate the Kepler-444 exoplanetary system using data from this website. The problem is that there is no argument of periapsis parameter for the Kepler-444 system, so while I think I'm ...
0
votes
1answer
67 views

Are galaxies moving in each direction with same speed?

All galaxies are moving away from each other (us) because of the expansion of the universe. Are they moving with same speed in each direction?
1
vote
1answer
31 views

White Dwarf/Degenerate Gas Behaviour

just want to try to clarify a few things about the nature of White Dwarfs and degenerate gases. So if a white dwarf is help up by an electron degenerate gas, the electrons are unable to lose energy ...
2
votes
0answers
43 views

Star rotational axes and Solar system orientations

How does the orientation of stars axes of rotation and any planetary systems relate to the plane of the galaxy? Is there any relationship that has been detected, are they grouped from their parental ...
2
votes
0answers
22 views

Asteroid identification in fits image

I have a fits image, and I need to identify an asteroid. What characteristics do I look out for?
2
votes
1answer
85 views

How come the Sun does not make the Moon crash on the Earth?

As the Moon loops around the Earth, on one side of the Earth it moves toward the Sun (let's call it downward side) and on the other side it moves away from the Sun (let's call it the upward side). ...
2
votes
1answer
43 views

Historical Distance of Planets to Earth [duplicate]

I'm curious if there is a readily accessible tool available, or simply a reliable way to find out what the distance of the planets in the solar system were on a given date. For example, if I am ...
0
votes
1answer
57 views

What's the proportion of Mars' surface compared to Earth's surface uncovered of water?

How does Mars surface compare to Earth's surface? Mars is quite smaller than Earth, but most Earth's surface is covered with water. I thought making the math could be relatively easy but Earth isnt a ...
1
vote
1answer
37 views

Mass of the universe

How do we calculate the mass of the universe taking into consideration dark matter? Mass of visible matter can be computed by stellar method, but how do we calculate mass of dark matter which we don'...
4
votes
0answers
45 views

Motivation for using $\sigma_{8}$?

Press-Schechter formalism allows one to universally quantify the number of massive dark matter halos in a given volume -- The Halo Mass Function. The density contrast is given by the rms mass variance ...
0
votes
0answers
21 views

Change in declination due to precession

If the presenet declination(0°) and R.A(3 h) are known , when will the declination have the same value again?
27
votes
2answers
4k views

Is there any known moon of a moon? [duplicate]

As far as I understand, a moon is an object in permanent orbit around a planet, dwarf-planet, asteroid, etc. If there was another object permanently orbiting this moon, would that be a moon-moon? Is ...
0
votes
0answers
41 views

How long a photon stay suspended in orbit around a black hole?

Can a black hole free from an accretion disk collect photons in the photon sphere in a prolonged stable orbit? Could enough photons be in orbit to shade the actual black hole with light? Would a ...
1
vote
0answers
49 views

Found green rock 20cm below surface, is this an meteor piece? [closed]

I am wondering if this rock on picture below is meteor fragment? If so what composition you think it is? It is magnetic i tried with magnet and it sticks to it very strong, it does have a lot of mass.
0
votes
1answer
30 views

Finding the diameter of a molecular cloud using period of intensity variation of hydroxyl maser

So I have this problem (which I translated to English as accurately as could): When studying a compact molecular cloud with radiotelescope, at a wavelength of 18 cm, hydroxyl (OH) maser(ic) ...
0
votes
1answer
48 views

How to calculate the time of Ekadashi days?

Is there an official reference algorithm for calculating the Ekadashi days? I found the textual description of Ekadashi calculation on wikipedia but can't really make sense of it in order to write ...
2
votes
1answer
59 views

How do we know that the mass ratio of hydrogen and helium in the sun is approximately 3:1?

From what I learnt, we can find what elements are in the sun by analysing spectrums since each elements has same emission spectrum, and when you look at the sun's spectrum, you can see absorption ...
1
vote
0answers
35 views

Astronomy/Astrophysics Project With C++/C/Python [closed]

I am a Computer Science Engineering student, in the 1st year of college. I'm insanely interested in making a project regarding astronomy/astrophysics but I don't know where to begin from. I know C, C++...
6
votes
2answers
100 views

Why do sun spots appear near the equator of the Sun?

I noticed on many examples sun spots are near the equator of the Sun. Why are there no sun spots closer to the poles of the Sun?
2
votes
1answer
284 views

Why the Circumstellar Habitable Zone is defined as it is, if life could be possible outside of it?

According to Circumstellar habitable zone In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a ...
2
votes
1answer
62 views

How was Cruithne's orbital time calculated?

How was it determined that Cruithne takes 770 years to complete its cycle with Earth? Janus and Epimetheus were disovered long enough ago, and have short enough cycle times, that we've had time to ...
2
votes
1answer
51 views

What causes random irregularities in the earth's rotation accounted for by dynamical time

I read in a book that the earth's rotation sometimes shows unpredictable irregularities(not caused by precession, nutation, tidal forces) which are accounted for using dynamical time. What would be ...
2
votes
1answer
71 views

How does making a refracting telescope very long reduce the chromatic aberration of an uncorrected lens?

Below are two cropped views of "Johannes Hevelius's 8 inch telescope with an open work wood and wire "tube" that had a focal length of 150 feet to limit chromatic aberration." from Harvard University, ...
3
votes
2answers
70 views

Can rogue/nomad planets and other starless planetary bodies orbit each other in a stable system?

Nomad planets (also called planemos or rogues planets) which drift in space without a star or substellar object to orbit. The majority of such planets we have discovered are gas planets with thick ...
3
votes
1answer
71 views

How can you verify the science presented on TV shows like “How the Universe Works” is current or valid? [closed]

What resources are there available where I could verify current scientific thinking on the origin of the universe theories?
3
votes
1answer
67 views

What does half-lit means?

Aristarchus estimated the relative distance of the Sun and Moon by observing the angle between the Sun and the Moon (α in the diagram) when the Moon is exactly half lit. Angle β must be 90° for ...
1
vote
1answer
60 views

What causes the duration of moon phases (the time the moon is visible above the horizon) to vary for an observer in the northern hemisphere?

Why does each phase of the moon stay up a different number of hours per phase, so that, for example, January’s full moon was up twice as long as the new moon? Plus every month this bulge shifts and at ...

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