madbadgalaxyman
01-04-2011, 10:32 PM
SDSS Data Release 8, the latest data release of the Sloan Digital Sky Survey, now makes available High Resolution images of 14000 square degrees of the Northern Sky. This is the majority of the Northern Sky. The new data release, which occurred in January 2011, covers 3000 square degrees more than the previous data release (which was Data Release number 7).
It is fast and easy to get really good images of northern galaxies, using the SDSS server on the internet. The SDSS images of galaxies are greatly superior to the DSS and DSS2 (Digital Sky Survey) images that observers have been using to find out “what a galaxy looks like”.
For those of you unfamiliar with the SDSS images of objects, they are at the High angular resolution of 1.4 arcseconds, or slightly better, though they are noisy compared to a good amateur LRGB image. As such, they are the best "quick access" ( .jpg, .gif, .html) survey images that are currently available on the internet.
( If you wish, you can find better images in data archives; but be ready for slow and laborious image searching, downloads, and image processing. )
So, how do you get your hands on these Hot images from the internet's best Virtual Telescope?
Firstly....... make sure that your Star Chart software is set to display the sky co-ordinates with the R.A. and Dec. of objects given in a decimal format (for instance: 000.0000).
Now find out the (decimal format) RA and Dec of your object of interest.
If your Charting software is zoomed in on the target object, then just using the mouse pointer (with care!) to find the R.A. and Dec of the centre of the object is accurate enough to find the approximate coordinates of the centre of the object.
I find that estimating the RA and Dec of the object of interest to three decimal places after the point, is good enough for the SDSS virtual telescope to be able to point itself at the target.
Secondly, to find the SDSS image of a specific Northern object, go to this website:
http://skyserver.sdss.org/dr8/en/tools/chart
At this website, click on the “Navigate” tool. This tool allows you to find images of any object that is within the 14000 square degree sky coverage of this Northern Sky survey. Another good feature of the “Navigate” tool is that the object can easily & quickly be viewed at various zoom levels and image scales.
Then.....just type in the decimal R.A. and Dec coordinates of your object of interest, into the appropriate (RA and Dec) boxes on the webpage.
This enables the display of a Sloan Digital Sky Survey image of whatever is at these coordinates.
[ A quick & easy way to transfer the image on the webpage to your image editing software is simply to press the PrintScreen key ; the image can then be Pasted into your software, from the Clipboard, and then saved as whatever file type you want.]
SDSS DR8 is undeniably the best Virtual Telescope on the internet.
The SkyMapper telescope at Siding Spring will soon be used to create a similar Virtual Telescope which will display images of everything in the southern sky.
Some information about the Southern Sky Survey can be found at:
http://msowww.anu.edu.au/skymapper/survey
It is fast and easy to get really good images of northern galaxies, using the SDSS server on the internet. The SDSS images of galaxies are greatly superior to the DSS and DSS2 (Digital Sky Survey) images that observers have been using to find out “what a galaxy looks like”.
For those of you unfamiliar with the SDSS images of objects, they are at the High angular resolution of 1.4 arcseconds, or slightly better, though they are noisy compared to a good amateur LRGB image. As such, they are the best "quick access" ( .jpg, .gif, .html) survey images that are currently available on the internet.
( If you wish, you can find better images in data archives; but be ready for slow and laborious image searching, downloads, and image processing. )
So, how do you get your hands on these Hot images from the internet's best Virtual Telescope?
Firstly....... make sure that your Star Chart software is set to display the sky co-ordinates with the R.A. and Dec. of objects given in a decimal format (for instance: 000.0000).
Now find out the (decimal format) RA and Dec of your object of interest.
If your Charting software is zoomed in on the target object, then just using the mouse pointer (with care!) to find the R.A. and Dec of the centre of the object is accurate enough to find the approximate coordinates of the centre of the object.
I find that estimating the RA and Dec of the object of interest to three decimal places after the point, is good enough for the SDSS virtual telescope to be able to point itself at the target.
Secondly, to find the SDSS image of a specific Northern object, go to this website:
http://skyserver.sdss.org/dr8/en/tools/chart
At this website, click on the “Navigate” tool. This tool allows you to find images of any object that is within the 14000 square degree sky coverage of this Northern Sky survey. Another good feature of the “Navigate” tool is that the object can easily & quickly be viewed at various zoom levels and image scales.
Then.....just type in the decimal R.A. and Dec coordinates of your object of interest, into the appropriate (RA and Dec) boxes on the webpage.
This enables the display of a Sloan Digital Sky Survey image of whatever is at these coordinates.
[ A quick & easy way to transfer the image on the webpage to your image editing software is simply to press the PrintScreen key ; the image can then be Pasted into your software, from the Clipboard, and then saved as whatever file type you want.]
SDSS DR8 is undeniably the best Virtual Telescope on the internet.
The SkyMapper telescope at Siding Spring will soon be used to create a similar Virtual Telescope which will display images of everything in the southern sky.
Some information about the Southern Sky Survey can be found at:
http://msowww.anu.edu.au/skymapper/survey