Milky way Definition and 184 Threads

It took just a couple of hours using data available on the internet for University of Sydney scientists to discover that the Milky Way is twice as wide as previously thought. Astrophysicist Professor Bryan Gaensler led a team that has found that our galaxy - a flattened spiral about 100,000...

Our Milky Way is a spiral galaxy whose ecliptic plane is the same with the ecliptic of the Sun (or nearly). So do you think all other solar systems in the Milky Way also have the same characteristics?

How far away is the average star in the night sky? I mean, can we see stars that are on the other side of the galaxy? Perhaps most of the visible stars are maybe just a few dozen light years away?

Have these papers been discused. http://arxiv.org/abs/0704.1125 High Galactic Latitude Interstellar Neutral Hydrogen Structure and Associated (WMAP) High Frequency Continuum Emission Authors: Gerrit L. Verschuur (Submitted on 9 Apr 2007 (v1), last revised 23 Jul 2007 (this version, v2))...

Do you think there are more stars in our Milky Way galaxy, or galaxies in the observable universe?

When we view the Milky Way with the naked eye from Earth in the winter night sky, we see the streakish 'cloud' of its spiral arms. Are we looking in toward its center toward the inner arms, or out toward its outer arms? And vice versa in summer? I don't recall ever noticing any difference in the...

The orbits of the Magellanic Clouds about the Milky Way Galaxy have apparently been determined, and the two dwarf irregular galaxies are now about as close as they will get to the MW in their 2.2 billion year orbit. See p. 42 of "Our Growing, Breathing Galaxy" by Wakker and Richter, Scientific...

Hey folks, I'm currently at grad school and am working on an algorithm to try and model the rate of supernova (type I and II) in our galaxy. I really need to know the following information. 1) Where can I find information on HOW MANY of the different types of stars there are in our...

The universe should be billions of times brighter than the Milky Way? I miscalculated =P The sun is 1 AU away. The center of the galaxy is 2 billion AU away. A sun at 2 billion AU away is 4 billion billion times dimmer than our sun. There are about 200 billion stars within the radius of the...

As I've searched, (correct me if I'm wrong) it seems that the pioneer spacecraft s (10 or 11) are the farthest things away from the solar system, yet, not yet quite far enough out to be in interstellar space. How is it that there are pictures of our galaxy, or is it merely another galaxy that...

for the following question: In its own frame of reference, a proton takes 5min to cross the Milky Way galaxy, which is about 10^5 light-years in diameter. What is the approximate energy of the proton in electronvolts? my problem: v*5*60=(10^5)*3*(10^8)*[1-(v^2/c^2)] however, i can't...

I thought this Slashdot story might be appropriate for here.

I hope this is the right section. But, can anyone here tell me how is it that we know the our galaxy is a spiral one, i don't doubt what I've read, but i need an explanation. I read something about density waves and how they power the rotation of our galaxy andor other galaxies. But how do we...

Some people argue the very low amount of technological civilizations in the Milky Way, some even say there is no other technological civilization in the galaxy, they argue this because they think the galaxy should have been colonized by now...I don't agree with this I don't think it will be...

Is the Andromeda Galaxy going to collide with the Milky Way? I've heard that the Andromeda Galaxy is going to collide with the Milky Way someday. I understand how its radial velocity relative with respect to the Milky Way is determined through its blueshift, but how do we know its tangental...

I'm thinking about taking a little road trip this spring. I have never seen the Milky Way and I am looking for a good viewing spot. I live in California and I am thinking about Joshua Tree for the location. Any other ideas? Thx.

hey guys, I'm new to physics .. and to be frank it seems scary. :-p anyways i was wondering if anyone could help me with this: The diameter of milky way is 1.0 *10^5 lightyears (ly). The distance to Andromeda is about 2.0 million ly. If a scale model represents the milky ways and andromeda...

how quickly is the milky way relative to the cosmic backround radiation on its way through the universe ? I mean not the rotation speed thank you

This paper: http://www.edpsciences.org/papers/aa/pdf/press-releases/aa0959.pdf ...press release: http://www.eso.org/outreach/press-rel/pr-2004/pr-08-04.html suggests that the kinematic heating (statistical dispersion of velocities in the perpendicular plane to the galactic plane) of...

ESA's Integral solves 30-year old gamma-ray mystery. Regular readers will recall that we've several times discussed this gamma glow seen in the direction of the Milky Way centre; some PF members have posted links to papers which propose mechanisms for it, some have put forward their own ideas...

On a related question to my last post, is there any consensus on the visible mass of the Milky Way? I've seen several recent mass calculations but they all assume Dark Matter. For my model I need to know the total visible matter of both the disk and the entire galaxy. I've seen old estimates...

I'm trying to put together a realistic simulation of the Milky Way. Can anyone direct me to a database or something I can scrape in order to get the density profile?

More specifically, when I look at the milky way am I seeing another arm of the galaxy or am I looking towards the center of the galaxy? I'm having a hard time finding a specific answer to this question. Thanks!

A star 890,000 light-years away patrols our galactic frontier By Ken Croswell, author of The Alchemy of the Heavens Just as every planet in the solar system orbits the sun, so every star in the Milky Way orbits the big black hole at our galaxy's center. But how far out does the Milky Way...

As many are aware, the announced detection of primordial gravity waves by BICEP 2 was heavily criticized based on dust emission modeling. Today, Planck XXV was released which mapped out the dust emissions of Andromeda. Assuming Andromeda is representative of the Milky Way in most relevant ways...

by Dr. Ken Croswell, author of The Alchemy of the Heavens The Milky Way may have found a solution to its gas shortage. Astronomers had calculated that our home galaxy possesses only enough fuel to forge new stars for just a few billion more years. But scientists have now discovered that a...

I am trying to find the density, scale radius and normal radius of the milky way's halo. But these things are pretty hard to find. I want to find them so I can input them into the NFW profile:

We have a good handle on what other galaxies look like, given that we're looking at them from a distance. But when I look at a depiction of our home galaxy, pointing out roughly where our solar system lies, do we really know with any degree of accuracy that this is what it looks like, or is it...

Important: All Logs are base 10 and not the natural log. Homework Statement This question is from Foundations of Astrophysics from chapter 19 Suppose the Milky Way consisted of 2.7x10^11 stars, each of solar luminosity MB=4.7. What would be the absolute magnitude of the whole galaxy? To...

Hello, Can anyone confirm or, refute and correct the following statements? The volume of our galaxy, is roughly 8 trillion cubic light years. The combined volume of all the stars in our galaxy only equals one cubic light year. Thanks for any help you can provide! Rusty

Does the center of the galaxy intersect the ecliptic? If so, is it a temporary coincidence?

1. Most of the atoms in the universe are not in stars but in ionized gas in intergalactic space. The Milky Way has mass in its stars equivalent to 50 billion Suns (5 x 10^10 Msun). If the gas in the intergalactic medium only has a density of one proton per cubic meter, about how big a volume...

Hi, I recall some years ago seeing a composite picture of what our galaxy would look like from outside the galaxy, for example from Andromeda but was not able to find one or even how to search for it on the web. I was wondering if anyone here is familiar with it and perhaps even if we've...

I live at 4000 feet above sea level and list night I saw some shooting stars, one real big one coming from the south so i thought I would star-gaze awhile and see if more meteors would come my way, no more came and after awhile I was admiring how well I could see the milky way and then I...

So here's a question I'm struggling with: The rotation speed of the sun around the Milky Way center is 220 km/s and it takes the sun around 200 million years to orbit once around center of the galaxy. Given that the rotation curve is relatively flat (i.e. the rotation speed stays the same as...

I have seen a depiction of the Sun traveling in it's orbit in the Milky Way. In this depiction, the Sun was bobbing up and down. 1. From what does the Sun get its movement orders from? (The black hole at the center of our galaxy?) 2. How come it bobs up and down, but none of the other...

Hello, Whenever I read over net or search over some pictures of galaxies, the Andromeda galaxy pops up in the list as first and some resources mention it to be the nearest galaxy to our Milky Way. Wikipedia suggests Canis Major Dwarf as the nearest: 0.025 mly. It is always in picture or...

It would be great if any of you could give me an aproximate formula of the star density of the milky way, as far as i know (and I'm not pretty sure), it falls off exponentially, both vertically and radially. The formula i have in my head would be something like ##Density \propto...

how will the pattern of stars in the milky way change as the galaxy rotates, will they be rotated in some direction or drifted or something? and what is the timescale for that to happen? Thanks!

The rotation speed of planets around the sun follows a simple rule: if you double the distance to the sun the rotation speed is reduced by the square root of 2. No matter the mass of the planet. If Earth mass was different the period of rotation around the sun will be exactly the same. But in...

The Milky Way is a Barred Spiral Galaxy 100,00 -120,000 Across. I was wondering if there is a website or list of what Stars of Constellations exist in what Spiral Arm. I there exists: Orion-Cygnus Arm Perseus Arm Scutum-Centaurus Arm Norma and Outer Arm Carina-Sagitarius Arm...

Homework Statement Is it possible to calculate the mass of the Milky Way knowing only the speed of a planet in a circular orbit? I fail to see how, but if yes, then how? Thanks in advance Homework Equations The Attempt at a Solution

In a recent article: http://io9.com/5937295/astronomers-discover-milky-ways-twin-magellanic-clouds-and-all Our galaxy is not particularly special in the universe. Its pairing with the Magellanic Clouds — two irregular dwarf galaxies has other similar configurations out there. I...

Homework Statement We are not allowed to use any videos from youtube. They have to be a realiable source. We are having difficulty copying the embeded link to the power point presentation. Homework Equations The Attempt at a Solution First, we right click on the video to copy it...

I and a few friends thought about the oort cloud... If it has 2 light years in lenght, that's half way to Alpha Centauri... What would stop our near neighbor Alpha Centauri to have its own oort cloud... And if this is wright couldn't the galaxy be filled with dwarf planets, asteroids and...

I'm wondering if there is any evidence that our own Galaxy 'crashed' with other Galaxies in the past (e.g. with the Andormeda Galaxy?). Is there any evidence for this? Googled... but couldn't find much. If so can someone point me at some research on this?

i was walking down the road, looking up at the stars and i wondered why i didn't see more, and specifically why i couldn't see the miky way stretching across. i live in the city, so i guess the fainter stars will be blocked out by light pollution. But surely the light from a billion stars...

In a 1925 paper, Erwin Schrödinger mentions that "our inertial systems are free of rotation precisely with respect to our stellar system", instead of being "anchored...in much more distant stellar masses". Is this really the case? If so, this suggests that the total gravitational potential...

i have been to the mountains and been to the beach lots of times looking up at the sky away from the city lights ,but i have never seen the milky way .i have seen lots of amazing pictures of it on the net from other places around the world .Then is it only possible to see it at certain times of...

As far as I know, the only evidence of a supermassive black hole (SMBH) at the center of our Milky Way has been it's gravitational effect on stars that zip around near the center of our galaxy and a radio signature. That's about to change in 2013 when a stream of ionized dust and gas begin it's...