Questions tagged [milky-way]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
1 vote
2 answers
71 views

Does the Milky Way have any impact on Earth?

Does which galaxy we are in (Milky Way) have any impact on Sun/Earth? What I mean is: suppose our solar system was instantly teleported into a different galaxy (eg Andromeda). Apart from the stars ...
user avatar
4 votes
2 answers
232 views

About the non-intuitive announcement at 12 May 2022 of the EHT team that spin axis of Sgr A* Black Hole facing Earth?

What is this all about?: At 12 May 2022 at the ESO official announcement live streaming event the EHT representatives claimed that the Sgr A* BH accretion disc spin axis is sort of facing Earth's ...
user avatar
  • 3,184
31 votes
3 answers
4k views

Why are there three bright spots in the first picture of Sagittarius A*?

Why are there 3 distinct bright spots? The old blackhole picture had half bright and half dark, which I believe is a result of the different relative velocities of particles orbiting it, (towards or ...
user avatar
  • 4,243
2 votes
1 answer
66 views

Are there tidal forces between the solar system and the galactic centre?

Tidal forces are experienced within a system moving in free fall around a bigger object because of the different strength of gravity over the system. The difference can be calculated between the far ...
user avatar
1 vote
6 answers
142 views

Are we totally limited to the Milky Way for all stellar astrophysics?

Simply put; Are we able to make any observations of the individual stars in other galaxies? Is the depth of our scientific knowledge on star systems, based solely on stars in the Milky Way Galaxy ...
user avatar
0 votes
0 answers
28 views

How large are the fictitious forces due to our orbit around the galactic center?

When we are in a non-intertial system, this creates fictitious forces. Some well-known fictitious forces are the centrifugal and coriolis forces. Those are caused by the Earth's spin around its axis. ...
user avatar
  • 484
2 votes
1 answer
78 views

How many full orbits around the galactic center our Earth has done so far since its creation?

I have read that the estimated age of our Milky Way galaxy is 13.61 billion years which is by using our current size and status of our galaxy about 59.17 Galactic years which each galactic year ...
user avatar
  • 3,184
2 votes
3 answers
124 views

How did astronomers at Edwin Hubble time decide the size of the Milky Way Galaxy and settled the Great Debate?

I have been reading some books about Great Debate that whether the Milky Way Galaxy was the entire universe and Edwin Hubble settled the debate by identifying some Cepheid variable star (V1) in ...
user avatar
8 votes
5 answers
1k views

Is there cosmological redshift within the Milky Way?

Cosmological redshift is based on the idea that the universe is expanding. When the universe doubles in size, or scale factor, the wavelength of light doubles. But the Milky Way is not expanding so my ...
user avatar
0 votes
0 answers
19 views

Can somebody describe the frame dragging around Sagittarius A at the center of our galaxy?

I need to be able to visualize it, specifically the number of turns and how it relates to the horizons in the black hole and what would happen to something falling in also described. Has anyone ever ...
user avatar
0 votes
1 answer
155 views

How is speed of Milky Way determined relative to CMB dipole?

I read that our galaxy the milky way is moving at approx 630km/s relative to CMB dipole, I think they applied Doppler shift to find this number but how do they do that? I know when universe is a hot ...
user avatar
  • 11.4k
6 votes
4 answers
2k views

Estimating of the size of the Milky Way from the Sun's motion

I am trying to run a simple first-principles calculation to estimate the diameter of the Milky Way from what we know about the motion of the Sun around its center. In particular, from various online ...
user avatar
0 votes
2 answers
44 views

Do we have to care about the force from the Milky Way black hole while analysing the Solar system from its Center of Mass frame?

And also while analysing Earth's spinning motion about its center? Do we have to care about the forces from the giant Black Hole at the center of Milky way? I guess we would have to take the Black ...
user avatar
  • 2,783
1 vote
1 answer
235 views

Will Milky way and Andromeda collide for sure?

Is it sure that Milky way and Andromeda will collide or might they just start a rotation around their center of masses?
user avatar
1 vote
1 answer
145 views

What is the luminosity of the Milky Way?

This question may appear to be the same as What is the luminosity of the Milky Way galaxy?, but that question references a value of $5\times 10^{36}\space W$, which comes from a Wiki page which ...
user avatar
0 votes
3 answers
153 views

Why is the Andromeda galaxy coming closer to Milky way?

If both these galaxies are on collision path because of their gravity but how could that be? They are 2.5 million light-years apart now but I imagine they are still n collision path for a long time ...
user avatar
  • 273
1 vote
2 answers
122 views

What's the energy of all the light/electromagnetic radiation in our galaxy?

I came upon this question while watching a pop-sci video on youtube about Dark Matter and thinking about all the things that could be contributing gravitational influence to a galaxy. From relativity ...
user avatar
  • 113
3 votes
2 answers
519 views

How will Andromeda collide with Milky Way in spite of Hubble's law? [duplicate]

According to Edwin Hubble our Universe is expanding because he noticed that other galaxies are moving away from us. But then how Andromeda galaxy will collide with Milky Way in ~4.5 billion years, as ...
user avatar
4 votes
2 answers
347 views

Where can I find visible/radio telescopic observations of the center of the Milky Way galaxy?

I recently stumbled across this time-lapse telescopic image (radio image, I believe) of the center of the galaxy. Here's a still image. Link to time-lapse video below. I haven't been able to find ...
user avatar
  • 428
1 vote
1 answer
40 views

Will the Sun's orbit around the Milky Way degrade once it transitions to a white dwarf with half its original mass?

Does the Sun's mass factor in at all when it comes to its orbit around the Milky Way, such that if it lost half its mass, its orbit would change? Or is it a matter of the center of the Milky Way being ...
user avatar
1 vote
1 answer
161 views

Why was the imaging of M87 black hole easier than imaging the Milky way's Sagittarius A*? [duplicate]

In the recent EHT press release of the image of the super massive black hole at M87, I am curious to know why the super massive black hole at the centre of milky way has not been imaged yet.
user avatar
  • 145
2 votes
1 answer
177 views

Milky Way Density

It seems to be a simple question, but I wasn't really able to find an appropriate answer: How dense is the Milky Way? I am certain that there are reliable statistic, maybe even new ones from the GAIA ...
user avatar
  • 850
4 votes
1 answer
440 views

What's the eccentricity of our sun's orbit around the center of the galaxy? [duplicate]

Just thinking about "galactic habitability zones." Is this even a valid question?
user avatar
  • 1,587
2 votes
2 answers
732 views

Dark matter density calculation

I find that the general dark matter density of the Milky Way is $$6.87 \times 10^9 \: \rm GeV/m^3$$ or $$1.225 \times 10^{-17} \: \rm kg/m^3$$ (by taking the size of the Milky Way and dividing it to ...
user avatar
  • 2,836
2 votes
1 answer
212 views

What does the gravitational potential of the Milky Way do to the CMB?

We sit in a gravitational potential, so there should be a blue shift on the CMB light from the potential of the Milky Way. Is this blue shift dependent on direction? Is it being subtracted from the ...
user avatar
  • 2,537
1 vote
0 answers
29 views

Is it possible to see the Milky Way galaxy through a gravitational lens? [duplicate]

I have been thinking about these amazing images of ancient galaxies we can see because of gravitational lensing. Some of them even have multiple images of the same galaxy in two different places ...
user avatar
  • 111
-1 votes
2 answers
4k views

Does the Sun revolve around the supermassive black hole at the center of the Milky Way? [duplicate]

I'm curious to know, does the sun really revolve around the black hole at the center of the galaxy?
user avatar
1 vote
2 answers
97 views

Path to a distant star

Suppose we have a space ship that can go fast enough (0.9c) and we have plenty of time, and we want to travel to a star on the other side of the galaxy. How do you plot a path to navigate to that star?...
user avatar
  • 3,126
40 votes
6 answers
11k views

What is the evidence for a supermassive black hole at the center of Milky Way?

Black holes cannot be seen because they do not emit visible light or any electromagnetic radiation. Then how do astronomers infer their existence? I think it's now almost established in the scientific ...
user avatar
1 vote
1 answer
173 views

Estimating total mass inside the Sun's orbit

I'm trying to estimate the local density of dark matter at a given radius, $r=R_0=8\text{kpc}$. I also have values for the core radius, $a=5\text{kpc}$, and circular velocity of the Sun, $v_{\text{...
user avatar
  • 215
1 vote
0 answers
31 views

Estimating the reddening of a star? [closed]

I'm stuck on a question concerning how to estimate the reddening of a star. The question is: "A star near the Galactic plane has observed apparent magnitudes in the blue and visual bands of $B = 15....
user avatar
  • 215
0 votes
1 answer
66 views

Milky way without black holes in the center [closed]

I understand that the Milky way is a spiral galaxy with a supermassive black hole in the center. I understand that because of the stress-energy and the gravitational field of the black hole, the ...
user avatar
3 votes
2 answers
208 views

The Sun's Orbit - Is it What We Think?

I was thinking that the sun must orbit something within our spiral arm in the Milky Way, or be affected by other astronomical bodies - surely not just the supermassive black hole centre. I have ...
user avatar
  • 75
2 votes
1 answer
453 views

What is the current shape of the Milky Way?

Things in the Universe which are thousands of light years away from Earth can be seen, or pictures can be taken by Hubble Telescope, because those stars, galaxies, etc. emitted light thousands, ...
user avatar
1 vote
1 answer
97 views

Is there a Neutron Star or Black Hole close to solar system?

I recently read an article where it mentioned that the solar system could be born out of a supernova explosion (death of a previous star). In case there was a supernova, wouldn't there be a ...
user avatar
  • 13
1 vote
1 answer
524 views

What is the local stellar number density?

Is it just me or does this paper, while providing a great equation for the behaviour of the general stellar number density, never actually give a value for the local stellar number density $\rho(R={\...
user avatar
12 votes
1 answer
2k views

If our galaxy's dark matter halo is so large and diffuse, why is the ordinary matter in it so much more localised and compactly located?

I just read that our galaxy's dark matter halo is estimated to be 1.5m ly across, compared to the visible galaxy's 100k ly across, needed to explain stellar rotation curves. Why would this be? By ...
user avatar
  • 4,097
0 votes
2 answers
152 views

If the Universe is expanding, then why will Andromeda collide with the Milky Way? [duplicate]

Andromeda is moving towards the Milky Way Galaxy at around 250,000 mph, but I wonder what is the direction of our Milky Way Galaxy? Are these two galaxies heading towards each other or Andromeda will ...
user avatar
-1 votes
1 answer
95 views

Frame Dragging by Sag A star

Is frame dragging by the supermassive black hole Sag A responsible for the milky way's rotation? If so would we also be part of time dilation depending on how close we are to Sag A? Is the gravity ...
user avatar
3 votes
2 answers
317 views

Milky Way: where does it end?

The milky way galaxy, as is typical for spirals (and others?), has a relatively flat rotation curve except very near the center: Eventually, at great enough distances, almost the entire mass of the ...
user avatar
1 vote
1 answer
63 views

During which part of the year does the Earth move toward the galactic centre?

The Earth orbits around the Sun which in turn orbits around the center of the Milky Way. In which part of the year is the Earth is moving away from the center of the Milky Way?
user avatar
0 votes
2 answers
95 views

Spin of Supermasive Blackhole

How long does it take for the black hole at the center of our galaxy to make 1 full rotation?
user avatar
1 vote
4 answers
169 views

Can a super-duper massive black hole eventually eat an entire galaxy?

Might there be some roaming black galaxies out there eating up other galaxies?
user avatar
1 vote
3 answers
446 views

How do we know the stars orbiting Sgr A* are orbiting a supermassive black hole and not just the center of mass of the Milky Way galaxy?

It is my understanding the best evidence we have for Sgr A* being the black hole at the center of our galaxy is the incredible velocities of the stars orbiting around it. But wouldn't the stars ...
user avatar
1 vote
2 answers
81 views

From a planet in one of our satellite dwarf galaxies, would one be able to see the Milky Way?

Say there was a lifeform not unlike ours native to a planet somewhere in one of our nearest satellite galaxies, say Sagittarius, during their nighttime would they be able to see the Milky Way brightly?...
user avatar
  • 19
2 votes
1 answer
238 views

On the trajectory of the Andromeda-Milky Way collision

The Andromeda-Milky Way collision is going to happen in approximately 4 billion years. What trajectory would the Andromeda galaxy follow on its path to collision with the Milky Way? How could this be ...
user avatar
  • 1,281
-3 votes
1 answer
155 views

Frequency of black holes [closed]

How many black holes are considered to exist in the Milky Way.. and is there evidence of a single supermassive black hole at its center?
user avatar
  • 323
4 votes
2 answers
224 views

Are we closer to an accurate 3D image of our galaxy using the Gaia billion star data set?

From the BBC: Report on Gaia Mission Data 14th September 2016 Astronomers working on the Gaia space telescope have released a first tranche of data recording the position and brightness of over a ...
user avatar
18 votes
2 answers
11k views

What angle does our Solar System make with The Milky Way?

Solar System resides in a plane, thanks to Conservation of Angular Momentum. The Milky Way is also a disc, not sphere. What angle does our Solar System's plane (or, normal to plane) make with The ...
user avatar
1 vote
2 answers
153 views

Plausibility of black hole in center of galaxy (apparent paradox?) [duplicate]

Reading a question on the Worldbuilding SE site a minute ago about a trip to the other side of the galaxy flying by the supermassive black hole in the center of our galaxy, my immediate first thought ...
user avatar
  • 353