APOD: A Milky Way Dawn (2014 Mar 29)

Comments and questions about the APOD on the main view screen.

APOD: A Milky Way Dawn (2014 Mar 29)

Postby APOD Robot » Sat Mar 29, 2014 4:13 am

Image A Milky Way Dawn

Explanation: As dawn broke on March 27, the center of the Milky Way Galaxy stood almost directly above the European Southern Observatory's Paranal Observatory. In the dry, clear sky of Chile's Atacama desert, our galaxy's dusty central bulge is flanked by Paranal's four 8 meter Very Large Telescope units in this astronomical fisheye view. Along the top, Venus is close to the eastern horizon. The brilliant morning star shines very near a waning crescent Moon just at the edge of one of the telescope structures. Despite the bright pairing in the east, the Milky Way dominates the scene though. Cut by dust lanes and charged with clouds of stars and glowing nebulae, the center of our galaxy sprawls across the darker zenith even as the deep blue sky grows brighter and buildings still glint in moonlight.

<< Previous APOD This Day in APOD Next APOD >>
User avatar
APOD Robot
Otto Posterman
 
Posts: 1902
Joined: Fri Dec 04, 2009 3:27 am

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Guest » Sat Mar 29, 2014 4:24 am

Hello,

Is this picture taken looking back at the centre of the Milky Way Galaxy?

Thanks,

Den
Guest
 

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Chris Peterson » Sat Mar 29, 2014 4:39 am

Guest wrote:Is this picture taken looking back at the centre of the Milky Way Galaxy?

Pretty close to it. The center of our galaxy is nearly overhead in the image.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
User avatar
Chris Peterson
Abominable Snowman
 
Posts: 9679
Joined: Wed Jan 31, 2007 11:13 pm
Location: Colorado, USA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Ann » Sat Mar 29, 2014 4:56 am

A Milky Way dawn under. :mrgreen:

Ann
Color Commentator
User avatar
Ann
4725 Å
 
Posts: 5884
Joined: Sat May 29, 2010 5:33 am

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Boomer12k » Sat Mar 29, 2014 7:55 am

Neat...you can basically see it from end to end...


:---[===] *
Boomer12k
:---[===] *
 
Posts: 1149
Joined: Sun Apr 22, 2007 12:07 am

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Nitpicker » Sat Mar 29, 2014 10:35 am

Boomer12k wrote:Neat...you can basically see it from end to end...


:---[===] *


Of course, from Earth, you can never see more than half (180°) of the Milky Way at any one time. In this image, the galaxy's backside is blocked by the Earth. (Not to mention that the core of the galaxy obscures everything on the far side of the core, in the so called observation shadow.)
User avatar
Nitpicker
Inverse Square
 
Posts: 1687
Joined: Fri Sep 20, 2013 2:39 am
Location: S27 E153

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Guest » Sat Mar 29, 2014 2:03 pm

Nitpicker wrote:is blocked by the Earth. (Not to mention

Not to mention all those scruffy buildings in the way ! Almost as cluttered as my site.
Shame, would have been a nice picture else :(
Guest
 

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Chris Peterson » Sat Mar 29, 2014 2:39 pm

Nitpicker wrote:Of course, from Earth, you can never see more than half (180°) of the Milky Way at any one time.

That is sort of true, but misleading. At times and places you can see the entire length of the Milky Way, with the missing half being above or below the galactic equator, not a segment of galactic longitude.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
User avatar
Chris Peterson
Abominable Snowman
 
Posts: 9679
Joined: Wed Jan 31, 2007 11:13 pm
Location: Colorado, USA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby neufer » Sat Mar 29, 2014 4:20 pm


Chris Peterson wrote:
Nitpicker wrote:
Of course, from Earth, you can never see more than half (180°) of the Milky Way at any one time.

That is sort of true, but misleading. At times and places you can see the entire length of the Milky Way, with the missing half being above or below the galactic equator, not a segment of galactic longitude.


http://www.flickr.com/photos/jasonc66/9420934880/

http://www.flickr.com/photos/astro_andre/6799748616/
Art Neuendorffer
User avatar
neufer
Vacationer at Tralfamadore
 
Posts: 11631
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby quigley » Sat Mar 29, 2014 4:58 pm

Will someone please answer the last question on yesterday's APOD discussion. I find all of the questions and answers so very interesting. Thanks!
quigley
 

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Guest » Sat Mar 29, 2014 8:37 pm

Chris Peterson wrote:
Guest wrote:Is this picture taken looking back at the centre of the Milky Way Galaxy?

Pretty close to it. The center of our galaxy is nearly overhead in the image.


Thanks Chris
Guest
 

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Nitpicker » Sat Mar 29, 2014 9:42 pm

Chris Peterson wrote:
Nitpicker wrote:Of course, from Earth, you can never see more than half (180°) of the Milky Way at any one time.

That is sort of true, but misleading. At times and places you can see the entire length of the Milky Way, with the missing half being above or below the galactic equator, not a segment of galactic longitude.


If I had left out the "(180°)" it would have been better. Viewing the galaxy when its plane aligns with the local horizon is hardly ideal (all that scruffy atmosphere and hills, trees, buildings, etc).
User avatar
Nitpicker
Inverse Square
 
Posts: 1687
Joined: Fri Sep 20, 2013 2:39 am
Location: S27 E153

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Chris Peterson » Sat Mar 29, 2014 10:52 pm

Nitpicker wrote:If I had left out the "(180°)" it would have been better. Viewing the galaxy when its plane aligns with the local horizon is hardly ideal (all that scruffy atmosphere and hills, trees, buildings, etc).

Not ideal, but certainly possible. From my house, I've seen about 270° of the Milky Way when it's very close to lying on the horizon.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
User avatar
Chris Peterson
Abominable Snowman
 
Posts: 9679
Joined: Wed Jan 31, 2007 11:13 pm
Location: Colorado, USA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby ems57fcva » Sun Mar 30, 2014 3:24 am

There is something about the contrast in this image that reveals something interesting: There appear to be two dust lanes in this image. What appears to be the foreground dust land starts on the upper right side of the Milky Way. As it come to the central bulge area, it heads downward and around the bulge, and comes back to the plane of the galaxy on the other side. Another dust lane in the background goes across the central bulge of the Milky Way. This can also be seen in http://apod.nasa.gov/apod/ap140212.html (where the second dust lane is above the central bulge) if you know what you are looking for.

I take this to indicate the the Sun offset from the plan of the galaxy a ways. so that at its closest to us we are viewing the foreground dust lane from a different angle than the background one. Another possibility is that the Milky Way is warped like may other spiral galaxies are. This could even be a combination of the two.
ems57fcva
Ensign
 
Posts: 38
Joined: Wed Feb 24, 2010 1:13 am
Location: Falls Church, VA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby ta152h0 » Sun Mar 30, 2014 3:28 am

can the souther cross be seen in this fisheye image ?
Wolf Kotenberg
ta152h0
Schooled
 
Posts: 827
Joined: Mon Aug 29, 2005 12:46 am
Location: Auburn, Washington, USA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby alter-ego » Sun Mar 30, 2014 4:01 am

ta152h0 wrote:can the souther cross be seen in this fisheye image ?

Yes.
Crux.JPG
You do not have the required permissions to view the files attached to this post.
A pessimist is nothing more than an experienced optimist
User avatar
alter-ego
Serendipitous Sleuthhound
 
Posts: 548
Joined: Mon Apr 21, 2008 4:51 am
Location: Redmond, WA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby alter-ego » Sun Mar 30, 2014 4:22 am

ems57fcva wrote:There is something about the contrast in this image that reveals something interesting: There appear to be two dust lanes in this image. What appears to be the foreground dust land starts on the upper right side of the Milky Way. As it come to the central bulge area, it heads downward and around the bulge, and comes back to the plane of the galaxy on the other side. Another dust lane in the background goes across the central bulge of the Milky Way. This can also be seen in http://apod.nasa.gov/apod/ap140212.html (where the second dust lane is above the central bulge) if you know what you are looking for.

I take this to indicate the the Sun offset from the plan of the galaxy a ways. so that at its closest to us we are viewing the foreground dust lane from a different angle than the background one. Another possibility is that the Milky Way is warped like may other spiral galaxies are. This could even be a combination of the two.

I believe that the answer is due to non-uniform matter distribution in the disk, maybe due to warping but not necessarily. The sun is currently considered to be <100 ly away from the galactic plane, and the average outer disk thickness is many thousands of light years. The perspective you're seeing is over 10's of thousands of light years. I think our displacement from the plane is too small to reveal the large structural differences in angle that you're referring to.
A pessimist is nothing more than an experienced optimist
User avatar
alter-ego
Serendipitous Sleuthhound
 
Posts: 548
Joined: Mon Apr 21, 2008 4:51 am
Location: Redmond, WA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Nitpicker » Sun Mar 30, 2014 4:36 am

Nitpicker wrote:Of course, from Earth, you can never see more than half (180°) of the Milky Way at any one time.


Chris Peterson wrote:
Nitpicker wrote:If I had left out the "(180°)" it would have been better. Viewing the galaxy when its plane aligns with the local horizon is hardly ideal (all that scruffy atmosphere and hills, trees, buildings, etc).

Not ideal, but certainly possible. From my house, I've seen about 270° of the Milky Way when it's very close to lying on the horizon.


Still less than half the Milky Way, just not by galactic longitude. And to see more than 180° of the galactic plane (i.e. the great circle representing 0° galactic latitude) you'd have to rely on atmospheric refraction, I think, and have a very good horizon.
User avatar
Nitpicker
Inverse Square
 
Posts: 1687
Joined: Fri Sep 20, 2013 2:39 am
Location: S27 E153

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby geckzilla » Sun Mar 30, 2014 4:54 am

Being on a mountain helps, too.
Just call me "geck" because "zilla" is like a last name.
User avatar
geckzilla
Ocular Digitator
 
Posts: 6135
Joined: Wed Sep 12, 2007 12:42 pm
Location: Fresh Meadows, NY

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby alter-ego » Sun Mar 30, 2014 5:06 am

Nitpicker wrote:
Nitpicker wrote:Of course, from Earth, you can never see more than half (180°) of the Milky Way at any one time.


Chris Peterson wrote:
Nitpicker wrote:If I had left out the "(180°)" it would have been better. Viewing the galaxy when its plane aligns with the local horizon is hardly ideal (all that scruffy atmosphere and hills, trees, buildings, etc).

Not ideal, but certainly possible. From my house, I've seen about 270° of the Milky Way when it's very close to lying on the horizon.


Still less than half the Milky Way, just not by galactic longitude. And to see more than 180° of the galactic plane (i.e. the great circle representing 0° galactic latitude) you'd have to rely on atmospheric refraction, I think, and have a very good horizon.


Everest Panorama.jpg


Yes, that and some altitude. Coincidentally, Mt. Everest is not only the highest point on Earth but also the galactic pole is at its zenith (almost). Some time ago I created the panorama above. The high altitude and remote location provides dark skies, and on average (counting horizon dip and atmospheric refraction) one can see to -2°galactic latitude. The geographic heading and sky azimuth are accurate, but milky way brightness, sky brightness, and stellar magnitude limit were subjectively set.
You do not have the required permissions to view the files attached to this post.
A pessimist is nothing more than an experienced optimist
User avatar
alter-ego
Serendipitous Sleuthhound
 
Posts: 548
Joined: Mon Apr 21, 2008 4:51 am
Location: Redmond, WA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Nitpicker » Sun Mar 30, 2014 5:35 am

alter-ego wrote:Yes, that and some altitude. Coincidentally, Mt. Everest is not only the highest point on Earth but also the galactic pole is at its zenith (almost). Some time ago I created the panorama above. The high altitude and remote location provides dark skies, and on average (counting horizon dip and atmospheric refraction) one can see to -2°galactic latitude. The geographic heading and sky azimuth are accurate, but milky way brightness, sky brightness, and stellar magnitude limit were subjectively set.


Very nice. Thanks.
User avatar
Nitpicker
Inverse Square
 
Posts: 1687
Joined: Fri Sep 20, 2013 2:39 am
Location: S27 E153

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Ann » Sun Mar 30, 2014 5:38 am

Yes, very nice, thank you! :D

Ann
Color Commentator
User avatar
Ann
4725 Å
 
Posts: 5884
Joined: Sat May 29, 2010 5:33 am

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby alter-ego » Sun Mar 30, 2014 5:45 am

Nitpicker wrote: Very nice. Thanks.

Ann wrote:Yes, very nice, thank you! :D


You are very welcome :D
A pessimist is nothing more than an experienced optimist
User avatar
alter-ego
Serendipitous Sleuthhound
 
Posts: 548
Joined: Mon Apr 21, 2008 4:51 am
Location: Redmond, WA

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby Nitpicker » Sun Mar 30, 2014 7:48 am

geckzilla wrote:Being on a mountain helps, too.


So long as you are not surrounded by even higher mountains. I live on a small hill, in the middle of a valley surrounded by bigger hills.
User avatar
Nitpicker
Inverse Square
 
Posts: 1687
Joined: Fri Sep 20, 2013 2:39 am
Location: S27 E153

Re: APOD: A Milky Way Dawn (2014 Mar 29)

Postby geckzilla » Sun Mar 30, 2014 7:59 am

Nitpicker wrote:
geckzilla wrote:Being on a mountain helps, too.


So long as you are not surrounded by even higher mountains. I live on a small hill, in the middle of a valley surrounded by bigger hills.

As if anyone would choose to interpret my statement in that way. :facepalm:
Just call me "geck" because "zilla" is like a last name.
User avatar
geckzilla
Ocular Digitator
 
Posts: 6135
Joined: Wed Sep 12, 2007 12:42 pm
Location: Fresh Meadows, NY

Next

Return to The Bridge: Discuss an Astronomy Picture of the Day

Who is online

Users browsing this forum: DotNetDotCom.org [Bot], Exalead [Bot] and 4 guests