About observational astronomy - Revision history

wikademia>Wikademia: moved Observational astronomy to About observational astronomy

2009-04-25T01:37:32Z

moved Observational astronomy to About observational astronomy

← Older revision	Revision as of 01:37, 25 April 2009
(No difference)

wikademia>Wikademia at 21:12, 11 April 2009

2009-04-11T21:12:02Z

← Older revision		Revision as of 21:12, 11 April 2009
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	[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[Wikipedia:Horsehead Nebula\|Horsehead Nebula]]]]		[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[Wikipedia:Horsehead Nebula\|Horsehead Nebula]]]]
	Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.		Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.
			{{ntnes}}
	== Introduction ==		== Introduction ==

wikademia>Wikademia: Text replace - 'w:' to 'Wikipedia:'

2009-04-11T18:18:07Z

Text replace - 'w:' to 'Wikipedia:'

← Older revision		Revision as of 18:18, 11 April 2009
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	[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[w:Horsehead Nebula\|Horsehead Nebula]]]]		[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[Wikipedia:Horsehead Nebula\|Horsehead Nebula]]]]
	Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.		Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.

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	== Activities ==		== Activities ==

	A CCD (Charge-coupled device) imaging system is a type of digital camera that is very sensitive to the dim light from distant objects. The CCD camera is attached to a telescope and the images are stored on a computer where they can later be analyzed. Astronomical images are stored in a computer file format called [[w:FITS\|FITS]]. These images can be opened and viewed by using computer software that understands this file format.		A CCD (Charge-coupled device) imaging system is a type of digital camera that is very sensitive to the dim light from distant objects. The CCD camera is attached to a telescope and the images are stored on a computer where they can later be analyzed. Astronomical images are stored in a computer file format called [[Wikipedia:FITS\|FITS]]. These images can be opened and viewed by using computer software that understands this file format.

	=== Browsing the sky ===		=== Browsing the sky ===

	We will start by using a program called the [[w:Aladin Sky Atlas\|Aladin Sky Atlas]] to retrieve images taken with a telescope and study them.		We will start by using a program called the [[Wikipedia:Aladin Sky Atlas\|Aladin Sky Atlas]] to retrieve images taken with a telescope and study them.

	*Open another window in your web browser by clicking on this link to the [http://aladin.u-strasbg.fr/AladinPreview Aladin previewer] program.		*Open another window in your web browser by clicking on this link to the [http://aladin.u-strasbg.fr/AladinPreview Aladin previewer] program.
	*In the text box enter the name of the object that we are interested in studying. Type '''M101''' and then click the '''Plate view''' button.		*In the text box enter the name of the object that we are interested in studying. Type '''M101''' and then click the '''Plate view''' button.

	This image shows an area of the sky that includes a [[w:galaxy\|galaxy]]. Where did this image come from? Aladin allows you to retrieve images from a number of different sources. This particular image was taken as part of the [[w:Palomar Sky Survey\|Palomar Sky Survey]]. The galaxy is the small spiral shape near the upper left. The galaxy is much more distant than the individual bright stars in this view. To get a closer look at the galaxy lets take a look at a more magnified view.		This image shows an area of the sky that includes a [[Wikipedia:galaxy\|galaxy]]. Where did this image come from? Aladin allows you to retrieve images from a number of different sources. This particular image was taken as part of the [[Wikipedia:Palomar Sky Survey\|Palomar Sky Survey]]. The galaxy is the small spiral shape near the upper left. The galaxy is much more distant than the individual bright stars in this view. To get a closer look at the galaxy lets take a look at a more magnified view.

	*In the Aladin window click on the '''back''' button to return to the search page. Then click on the '''Default image''' button to retrieve a closeup image of M101.		*In the Aladin window click on the '''back''' button to return to the search page. Then click on the '''Default image''' button to retrieve a closeup image of M101.

	A galaxy is composed of [[w:star\|stars]] and the brighter parts of the image indicate places within the galaxy where there is a greater concentration of stars, for instance in the [[w:spiral galaxy\|spiral arms]]. The common name for this object is the [[w:Pinwheel Galaxy\|Pinwheel Galaxy]]. Astronomers also refer to it using a designation in an [[w:astronomical catalog\|astronomical catalog]]. The Pinwheel Galaxy is number 101 in a [[w:Messier object\|list of objects]] catalogued by astronomer [[w:Charles Messier\|Charles Messier]].		A galaxy is composed of [[Wikipedia:star\|stars]] and the brighter parts of the image indicate places within the galaxy where there is a greater concentration of stars, for instance in the [[Wikipedia:spiral galaxy\|spiral arms]]. The common name for this object is the [[Wikipedia:Pinwheel Galaxy\|Pinwheel Galaxy]]. Astronomers also refer to it using a designation in an [[Wikipedia:astronomical catalog\|astronomical catalog]]. The Pinwheel Galaxy is number 101 in a [[Wikipedia:Messier object\|list of objects]] catalogued by astronomer [[Wikipedia:Charles Messier\|Charles Messier]].

	*Now use Aladin to retrieve a color image of M101 by clicking on the '''RGB image''' button.		*Now use Aladin to retrieve a color image of M101 by clicking on the '''RGB image''' button.

	The cameras used by astronomers only capture [[w:greyscale\|greyscale]] images. To produce a color composite image requires taking separate exposures through color filters - usually red, green and blue. The three exposures are then combined to produce a final color image. In the color image of M101 you can see that the three separate exposures are not perfectly lined up which is why there is a purple border around the edge.		The cameras used by astronomers only capture [[Wikipedia:greyscale\|greyscale]] images. To produce a color composite image requires taking separate exposures through color filters - usually red, green and blue. The three exposures are then combined to produce a final color image. In the color image of M101 you can see that the three separate exposures are not perfectly lined up which is why there is a purple border around the edge.

	*Click on the '''New query''' button in Aladin. Just below the search text box there is a list of examples. Retrieve images of some of the other galaxies listed such as the [[w:Triangulum Galaxy\|Triangulum Pinwheel]] by clicking on '''M33'''.		*Click on the '''New query''' button in Aladin. Just below the search text box there is a list of examples. Retrieve images of some of the other galaxies listed such as the [[Wikipedia:Triangulum Galaxy\|Triangulum Pinwheel]] by clicking on '''M33'''.

	Take a look at [[b:Astronomy/Types of Galaxies\|types of galaxies]] and [[w:Galaxy classification\|galaxy classification]] as you look at the images. Try to classify each galaxy. Is it [[w:spiral galaxy\|spiral]], [[w:elliptical galaxy\|elliptical]], or [[w:Irregular galaxy\|another type]]?		Take a look at [[b:Astronomy/Types of Galaxies\|types of galaxies]] and [[Wikipedia:Galaxy classification\|galaxy classification]] as you look at the images. Try to classify each galaxy. Is it [[Wikipedia:spiral galaxy\|spiral]], [[Wikipedia:elliptical galaxy\|elliptical]], or [[Wikipedia:Irregular galaxy\|another type]]?

	=== Creating color images ===		=== Creating color images ===
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	*In the Aladin multiview window click on the icon labeled '''rgb'''. In the '''RGB image generator''' window use the pulldown menu to select the images for each color. For '''Red''' choose the image name that includes '''POSS1_Red'''. For '''Green''' leave it set to '''none'''. For '''Blue''' choose the image name that begins '''POSS1_Blue'''. Click on the '''Create''' button.		*In the Aladin multiview window click on the icon labeled '''rgb'''. In the '''RGB image generator''' window use the pulldown menu to select the images for each color. For '''Red''' choose the image name that includes '''POSS1_Red'''. For '''Green''' leave it set to '''none'''. For '''Blue''' choose the image name that begins '''POSS1_Blue'''. Click on the '''Create''' button.

	A third image will now appear in the Aladin multiview window. This type of image is called [[w:False-color\|False-color]] because the colors do not exactly match what the human eye would see when looking through a telescope.		A third image will now appear in the Aladin multiview window. This type of image is called [[Wikipedia:False-color\|False-color]] because the colors do not exactly match what the human eye would see when looking through a telescope.

	*You can use the '''Zoom''' button below the thumbnail image to change the scale of the main image. A zoom setting of '''1X''' will give you the largest image that can be displayed, without loss of resolution. Clicking on the thumbnail will center that spot in the main window image.		*You can use the '''Zoom''' button below the thumbnail image to change the scale of the main image. A zoom setting of '''1X''' will give you the largest image that can be displayed, without loss of resolution. Clicking on the thumbnail will center that spot in the main window image.
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	Background information:		Background information:
	* [[w:Observational astronomy\|Observational astronomy]]		* [[Wikipedia:Observational astronomy\|Observational astronomy]]
	* [[w:Telescope\|Telescope]]		* [[Wikipedia:Telescope\|Telescope]]

	==References==		==References==

wikademia>Wikademia: Text replace - 'Wikiversity' to 'Wikademia'

2009-04-11T05:07:24Z

Text replace - 'Wikiversity' to 'Wikademia'

← Older revision		Revision as of 05:07, 11 April 2009
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	The activities in this learning project are based on the idea of learning by doing. You will learn about astronomy by going through the same process that an astronomer does to analyze data. As you follow the instructions in the activity you should also follow the links to related reading materials.		The activities in this learning project are based on the idea of learning by doing. You will learn about astronomy by going through the same process that an astronomer does to analyze data. As you follow the instructions in the activity you should also follow the links to related reading materials.

	A [[~~Wikiversity~~:learning projects\|learning project]] is a collection of pages devoted to the Learning of a specific topic or family of topics; and, simultaneously, a group of people that use said pages to collaborate on a learning goal.		A [[Wikademia:learning projects\|learning project]] is a collection of pages devoted to the Learning of a specific topic or family of topics; and, simultaneously, a group of people that use said pages to collaborate on a learning goal.

	This page is the start of a series of related activities that will be created here during the first half of 2007. Visit the [[/Planning\|planning page]] to see some ideas on how this project might develop, and check back often to see the progress. There are also new projects to [[/Supernova\|observe supernova]] and study [[/Extrasolar planet\|extrasolar planets]] which have just started.		This page is the start of a series of related activities that will be created here during the first half of 2007. Visit the [[/Planning\|planning page]] to see some ideas on how this project might develop, and check back often to see the progress. There are also new projects to [[/Supernova\|observe supernova]] and study [[/Extrasolar planet\|extrasolar planets]] which have just started.

wikademia>Wikademia at 16:37, 4 April 2009

2009-04-04T16:37:53Z

← Older revision		Revision as of 16:37, 4 April 2009
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	[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[w:Horsehead Nebula\|Horsehead Nebula]]]]		[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[w:Horsehead Nebula\|Horsehead Nebula]]]]
	~~{{featured}}~~

	Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.		Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.

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	==References==		==References==

	Additional helpful readings include:		Additional helpful readings include:
	*[http://www.spacetelescope.org/projects/fits_liberator/improc.html Image processing introduction]		*[http://www.spacetelescope.org/projects/fits_liberator/improc.html Image processing introduction]

wikademia>Wikademia: 56 revisions

2009-03-29T19:38:37Z

56 revisions

← Older revision	Revision as of 19:38, 29 March 2009
(No difference)

wikademia>Michael Devore: /* Browsing the sky */ typos

2008-10-07T22:21:37Z

Browsing the sky: typos

← Older revision		Revision as of 22:21, 7 October 2008
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	*Now use Aladin to retrieve a color image of M101 by clicking on the '''RGB image''' button.		*Now use Aladin to retrieve a color image of M101 by clicking on the '''RGB image''' button.

	The cameras used by astronomers only capture [[w:greyscale\|greyscale]] images. To produce a color composite image requires taking ~~seperate~~ exposures through color filters - usually red, green and blue. The three exposures are then combined to produce a final color image. In the color image of M101 you can see that the three ~~seperate~~ exposures are not perfectly lined up which is why there is a purple border around the edge.		The cameras used by astronomers only capture [[w:greyscale\|greyscale]] images. To produce a color composite image requires taking separate exposures through color filters - usually red, green and blue. The three exposures are then combined to produce a final color image. In the color image of M101 you can see that the three separate exposures are not perfectly lined up which is why there is a purple border around the edge.

	*Click on the '''New query''' button in Aladin. Just below the search text box there is a list of examples. Retrieve images of some of the other galaxies listed such as the [[w:Triangulum Galaxy\|Triangulum Pinwheel]] by clicking on '''M33'''.		*Click on the '''New query''' button in Aladin. Just below the search text box there is a list of examples. Retrieve images of some of the other galaxies listed such as the [[w:Triangulum Galaxy\|Triangulum Pinwheel]] by clicking on '''M33'''.

wikademia>Gbaor: featured resource

2008-09-29T17:40:23Z

featured resource

← Older revision		Revision as of 17:40, 29 September 2008
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	[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[w:Horsehead Nebula\|Horsehead Nebula]]]]		[[Image:Barnard33.jpg\|thumb\|right\|300px\|The [[w:Horsehead Nebula\|Horsehead Nebula]]]]
			{{featured}}

	Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.		Astronomers can gain an understanding of objects in the universe by studying them with a telescope. Observational astronomy is the process of collecting and analyzing data to learn about these objects. In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.

wikademia>Cormaggio: reverting vandalism

2008-02-08T13:46:20Z

reverting vandalism

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 Astronomers can gain an understanding of objects in the universe by studying them with a telescope.  Observational astronomy is the process of collecting and analyzing data to learn about these objects.  In this learning project a computer program will be used to view and study images taken with a telescope to learn basic concepts in astronomy.
 == Activities ==
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 A CCD (Charge-coupled device) imaging system is a type of digital camera that is very sensitive to the dim light from distant objects.  The CCD camera is attached to a telescope and the images are stored on a computer where they can later be analyzed.  Astronomical images are stored in a computer file format called [[w:FITS|FITS]].  These images can be opened and viewed by using computer software that understands this file format.
 === Creating color images ===
 === Supernova ===
 ==Readings==

212.219.59.241: /* Supernova */

2008-02-08T13:31:02Z

Supernova

← Older revision		Revision as of 13:31, 8 February 2008
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	=== Supernova ===		=== Supernova ===

	The [[Observational astronomy/Supernova]] page has images of galaxies where a supernova has been observed recently. In this activity we will retrieve images taken before the supernova occured, and compare them to the new images.

	~~[[Image:UGC14.jpg\|thumb\|300px\|right\|Supernova 2006sr in the galaxy UGC 14 on 2007-01-02]]~~

	*Start Aladin and click on the '''Load...''' button. In the '''Server selector''' window click on '''DSS''' and select an image server. In the '''Target''' box enter the name of the galaxy which is '''UGC14''' and then choose '''POSS1_Red''' for the '''Survey'''. Click '''Submit'''.

	*In the Aladin multiview window click on the icon labeled '''pixel'''. In the '''Pixel mapping''' popup window click on the '''Reverse''' button to change the image from a negative to a positive.

	*To find out when this image was taken click on the icon labeled '''prop''' and look for '''Date-Obs:''' which indicates that the image was taken Aug. 11, 1953.

	*Compare the image displayed in Aladin to the image shown at right. Click [[:Image:UGC14.jpg\|here]] (or on the image) to see a larger version and to find out when it was taken (the '''Date''' is '''2007-01-02T23:03Z'''.) This supernova was first seen on Dec. 12, 2006, so it will not be visible in the earlier image displayed by Aladin. Do you see the supernova in the recent image? If you are unsure, click [[:Image:06srMU C200701022303.jpg\|here]] to see another version of this image that is marked to show which star the supernova is.

	*More images of this supernova can be found in [[:Category:Supernova Images]] or at the [http://www.rochesterastronomy.org/sn2006/sn2006sr.html Supernova 2006sr in UGC 14] webpage. Compare images taken on different dates to see if the supernova has changed brightness. The difference will be very subtle in images taken a week apart. It is more [[:Image:06srMU C200701262343.jpg\|obvious]] after about a month.

	==Readings==		==Readings==