|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
PHOTO OF THE WEEK, NGC2336 in Cam
This week we have NGC2336 in Camelopardalis.
This giant spiral galaxy lies at a distance of about 96 million light years. It is 178,000 light years across or about the same size as our Milky Way. js -- Astronomy, Beer, Cheese, Gems, Sausage http://schmidling.netfirms.com |
#2
|
|||
|
|||
PHOTO OF THE WEEK, NGC2336 in Cam
Jack
The Milky Way is approximately 80,000 light years across (ignoring the commonly quoted and incorrect figure of 100,000 ly and ignoring a few halo stars and tenuous gas clouds). [refer Bok and Bok "The Milky Way" 5th edition - p25 gives a value of 25kpc] ....so it must be TWICE the size of our Milky Way......... "Jack Schmidling" wrote in message om... This week we have NGC2336 in Camelopardalis. This giant spiral galaxy lies at a distance of about 96 million light years. It is 178,000 light years across or about the same size as our Milky Way. js -- Astronomy, Beer, Cheese, Gems, Sausage http://schmidling.netfirms.com |
#3
|
|||
|
|||
PHOTO OF THE WEEK, NGC2336 in Cam
William Phillips posted:
The Milky Way is approximately 80,000 light years across (ignoring the commonly quoted and incorrect figure of 100,000 ly and ignoring a few halo stars and tenuous gas clouds). The precise diameter of the Milky Way is not known. Like many other galaxies, the edges are irregular and not well defined (and we can't really see the "edge" very clearly even if there is a well-defined one due to our position in the galaxy). There was even a broad "ring" of stars recently discovered in the galactic plane nearly 120,000 light years from the galactic center. Thus, estimates for its diameter range from around 75,000 to as much as 120,000 light years. This does *not* necessarily make the 100,000 light year figure "incorrect", but merely one of many educated estimates for the size of the galaxy. Clear skies to you. -- David W. Knisely Prairie Astronomy Club: http://www.prairieastronomyclub.org Hyde Memorial Observatory: http://www.hydeobservatory.info/ ********************************************** * Attend the 11th Annual NEBRASKA STAR PARTY * * July 18-23, 2004, Merritt Reservoir * * http://www.NebraskaStarParty.org * ********************************************** |
#4
|
|||
|
|||
PHOTO OF THE WEEK, NGC2336 in Cam
The precise diameter of the Milky Way is well known. There is nothing much beyond 80,000 light years except some tenous gas and halo stars that merge with the intergalactic medium. From Andromeda, the Milky Way disk would be very clearly defined at this value. "David Knisely" wrote in message ... William Phillips posted: The Milky Way is approximately 80,000 light years across (ignoring the commonly quoted and incorrect figure of 100,000 ly and ignoring a few halo stars and tenuous gas clouds). The precise diameter of the Milky Way is not known. Like many other galaxies, the edges are irregular and not well defined (and we can't really see the "edge" very clearly even if there is a well-defined one due to our position in the galaxy). There was even a broad "ring" of stars recently discovered in the galactic plane nearly 120,000 light years from the galactic center. Thus, estimates for its diameter range from around 75,000 to as much as 120,000 light years. This does *not* necessarily make the 100,000 light year figure "incorrect", but merely one of many educated estimates for the size of the galaxy. Clear skies to you. -- David W. Knisely Prairie Astronomy Club: http://www.prairieastronomyclub.org Hyde Memorial Observatory: http://www.hydeobservatory.info/ ********************************************** * Attend the 11th Annual NEBRASKA STAR PARTY * * July 18-23, 2004, Merritt Reservoir * * http://www.NebraskaStarParty.org * ********************************************** |
#5
|
|||
|
|||
PHOTO OF THE WEEK, NGC2336 in Cam
William Phillips posted:
The precise diameter of the Milky Way is well known. There is nothing much beyond 80,000 light years except some tenous gas and halo stars that merge with the intergalactic medium. From Andromeda, the Milky Way disk would be very clearly defined at this value. Ok, so who took you out in their trans-warp driven starship to view the area? There is *no* fully-agreed upon value for the "well-known" diameter of the Milky Way. There are only "estimates", ranging from 75,000 to over 120,000 light years. We know the distance from the sun to the galactic core far better than we know the diameter of our galaxy. -- David W. Knisely Prairie Astronomy Club: http://www.prairieastronomyclub.org Hyde Memorial Observatory: http://www.hydeobservatory.info/ ********************************************** * Attend the 11th Annual NEBRASKA STAR PARTY * * July 18-23, 2004, Merritt Reservoir * * http://www.NebraskaStarParty.org * ********************************************** |
#6
|
|||
|
|||
PHOTO OF THE WEEK, NGC2336 in Cam
I think the values have been refined substantially over the last few
decades. Waller & Hodge confirms the 80,000 ly value, and indicates that the halo extends out to 300,000 ly. Sure, they are only estimates, but would be good to +/-10% "David Knisely" wrote in message ... William Phillips posted: The precise diameter of the Milky Way is well known. There is nothing much beyond 80,000 light years except some tenous gas and halo stars that merge with the intergalactic medium. From Andromeda, the Milky Way disk would be very clearly defined at this value. Ok, so who took you out in their trans-warp driven starship to view the area? There is *no* fully-agreed upon value for the "well-known" diameter of the Milky Way. There are only "estimates", ranging from 75,000 to over 120,000 light years. We know the distance from the sun to the galactic core far better than we know the diameter of our galaxy. -- David W. Knisely Prairie Astronomy Club: http://www.prairieastronomyclub.org Hyde Memorial Observatory: http://www.hydeobservatory.info/ ********************************************** * Attend the 11th Annual NEBRASKA STAR PARTY * * July 18-23, 2004, Merritt Reservoir * * http://www.NebraskaStarParty.org * ********************************************** |
#7
|
|||
|
|||
PHOTO OF THE WEEK, NGC2336 in Cam
William Phillips posted:
I think the values have been refined substantially over the last few decades. Waller & Hodge confirms the 80,000 ly value, and indicates that the halo extends out to 300,000 ly. Sure, they are only estimates, but would be good to +/-10% Can you cite the specific research paper where this value is stated and how this alleged level of accuracy has been obtained? The "standard" diameter in the literature appears to still be "approximately" 30 kpc (nearly 100,000 light years). I still have grave doubts that anyone could come to an estimate which was accurate to even 30% (most star distances beyond those measurable by trigonometric parallax are probably no more accurate than 20% to 30%). To say that the diameter of our galaxy is known to within +/- 10% is ludicrous. -- David W. Knisely Prairie Astronomy Club: http://www.prairieastronomyclub.org Hyde Memorial Observatory: http://www.hydeobservatory.info/ ********************************************** * Attend the 11th Annual NEBRASKA STAR PARTY * * July 18-23, 2004, Merritt Reservoir * * http://www.NebraskaStarParty.org * ********************************************** |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
PHOTO OF THE WEEK, New Program | Jack Schmidling | Astronomy Misc | 0 | June 15th 04 01:47 PM |
PHOTO OF THE WEEK, New Program | Jack Schmidling | Amateur Astronomy | 0 | June 15th 04 01:47 PM |
PHOTO OF THE WEEK, NGC2336 in Cam | Jack Schmidling | Astronomy Misc | 6 | May 25th 04 05:34 AM |
PHOTO OF THE WEEK, NGC2336 in Cam | Jack Schmidling | Amateur Astronomy | 8 | May 25th 04 05:34 AM |