Actions

Difference between revisions of "Remote Telescope Requests"

From AstroEd

(Limitations)
 
(40 intermediate revisions by the same user not shown)
Line 1: Line 1:
== Remote Telescope Use ==
+
== Remote Telescope Data ==
  
 +
Today’s computer technology, modern optics, and electronics allow astronomers and students to "see" the sky without enduring long freezing nights looking through an eyepiece.  The data we acquire are quantitative measurements of how much light arrives from fields of view that can be tiny and cover only a few stars, or vast, and cover constellations.  They can tell you the positions of moving objects, the variations in their brightness, their colors, details of the structure, and how they interact or relate with nearby companions.  Modern astronomy is evolving in the development of a new class of very large telescopes that by mid-2020's will have public data over the entire sky updated almost nightly. Smaller telescopes and instruments in space follow up on the discoveries offered by these big telescopes with closer inspection and careful analysis.
  
Today's computer technology, modern optics, and electronics offer an opportunity to provide you with access to research quality telescopes in both the northern and southern hemispheres. The University of Louisville and the University of Southern Queensland operate remotely controlled telescopes at Moore Observatory near Brownsboro, Kentucky, and at Mount Kent Observatory near Toowoomba, Australia. We are developing the capability to allow students to control these telescopes from home, taking advantage of the fact that it is nighttime at one site when it is daytime at another.
+
If you are interested in this future world, you can read more at websites for Gaia, a new satellite beginning to return amazing measurements of distances throughout our own galaxy, and of LSST, a "synoptic survey" telescope under construction in Chile.
 +
 
 +
*[https://www.lsst.org/ Link to LSST at  https://www.lsst.org/ ]
 +
*[http://sci.esa.int/gaia/ Link to Gaia at http://sci.esa.int/gaia/]
 +
 
 +
 
 +
 
 +
The University of Louisville and the University of Southern Queensland operate remotely controlled telescopes at Moore Observatory near Brownsboro, Kentucky,   at Mount Kent Observatory near Toowoomba, Australia, and on Mt. Lemmon in Arizona.
 +
For more than 10 years we have been acquiring data for research and student use, and we have an archive of many of the bright objects that may interest you.
 +
This semester our  telescopes in Kentucky,  Arizona,  and Australia are   operating robotically under the supervision of  professional astronomers  and can also acquire new images to meet your requests as well. 
 +
 
 +
This week your lab activity is to thoughtfully identify something in the sky that really grabs your interest.  It can be anything, but because there are limitations on what we can observe we will make a few suggestions to guide your thoughts.  With that, ask some questions yourself -- we are reversing roles here!  Why would you like to see this object, and what would you like to learn about it that a telescope image or measurement could reveal?
  
This semester one telescope at Moore Observatory in Kentucky is available with full remote control, and others are operating robotically under the supervision of a professional astronomer acquiring images to meet your requests. This is actually the way that most research astronomy is done today: astronomers pose a problem they want to solve, identify new data that would help them understand the issues, request time on a telescope and specify how that time would be used, get the data back from the telescope, analyze their results, and come to conclusions about the problem they had set out to study. Our goal in this experiment is to offer you an experience like this, and to help you work through the steps to learn by “discovery”
 
  
 
== Available Resources ==
 
== Available Resources ==
 +
  
 
The observatories are described on our website at
 
The observatories are described on our website at
  
http://sharedskies.org
+
[http://sharedskies.org http://sharedskies.org]
 +
 
  
 
and you are encouraged to explore it to see about the observatories and their telescopes. The content is currently under development, and may change during the semester.
 
and you are encouraged to explore it to see about the observatories and their telescopes. The content is currently under development, and may change during the semester.
  
The facilities you have access to include:
+
The facilities we  have access to include:
 +
 +
* Moore Observatory in the northern hemisphere near Brownsboro, Kentucky
 +
* Mt. Kent Observatory in the southern hemisphere near Toowoomba, Australia
 +
* Mt. Lemmon Observatory in Arizona, near Tucson
  
* Moore Observatory in the northern hemisphere near Brownsboro, Kentucky
 
  
* Mt. Kent Observatory in the southern hemisphere near Toowoomba, Australia
+
At both observatories we have identical 0.5 meter (20 inch) diameter "CDK20" research telescopes operating with a CCD camera and a selection of filters. These are the primary telescopes for this program. We offer other instruments too, and we are developing the capability to  have you visit us through the web when the telescopes are in operation and to press the "shutter button" yourself.  For example there are
  
 +
* A fast wide field Shared Skies Live telescope at Moore Observatory to take images of stars and nebulae through special filters.
 +
* A special long-focus telescope at Moore Observatory to take images of planets
 +
* Color cameras to quickly image star patterns, constellations, or comets that may span many degrees.
 +
* Two 0.6 meter (24 inch) "RC24" research telescope at Moore Observatory and Mt. Lemmon are used primarily to study planets around other stars
 +
* A 0.7 meter (27 inch) "CDK700" telescope at Mt. Kent observatory that will be used for spectroscopy, the analysis of starlight, for assisting the new NASA TESS satellite that is to launch soon.
  
At both observatories we have identical 0.5 meter (20 inch) diameter "CDK20" research telescopes operating with a CCD camera and a selection of filters. These are the primary telescopes for this program. We offer other instruments too
 
  
* A 0.36 meter (14 inch) "C14" - the Shared Skies Live telescope at Moore Observatory takes full color images of planets and offers a web interface for real time control
+
Also we have a substantial improving archive of the best images that we add to often. We will draw from it when we can to satisfy your requests.
* Wide field color cameras for imaging the entire sky, constellations, or comets that may span many degrees
 
* A 0.6 meter (24 inch) "RC24" research telescope at Moore Observatory used primarily to study planets around other stars
 
  
We also have a growing archive of images acquired over the past few years that we provide if a request for a current image cannot be accomodated or we have something already done that we can offer quickly.
 
  
 
== What the Telescopes Can Show ==
 
== What the Telescopes Can Show ==
  
Except the color cameras, the CCD cameras on the telescopes return scientific images as digital files in “FITS”  format. These images may be viewed with ImageJ, Aladin,  or other software you load on your own computer. The JPG images color pictures are  the same type as you would usually have from your own digital camera. They may be useful if you are interested in seeing form or structure, watching craters or shadows on the Moon, following the rotation of Jupiter or Mars, or looking for the colors of stars.
 
  
Also except for the special wide field cameras, these telescopes cover a field about half a degree across, the apparent size of the Moon. Each pixel resolves about 0.5 arcsecond (there are 3600 arcseconds in a degree), and measures how much light arrived at that spot in the image for the duration of the exposure. By comparing one pixel with another, you can tell how much brighter or fainter one feature of the image is compared to another. The image that you see, while visually exciting, is also a tool to measure how much light there is and where it is.
+
Except the color cameras used to record wide field images of constellations and the occasional comet, the CCD cameras on the telescopes return scientific images as digital files in “FITS”  format. These images may be viewed in your computer's browser with some tools we will provide, or with  other software you load on your own computer.  those images require some effort to analyze, but they offer quantitative data on positions and brightnesses.  Over the next few weeks you will be using some of the software that is needed and gain experience with what it can do.
 +
 
 +
In many cases we will produce color images from these data that  may be useful if you are interested in seeing form or structure, watching craters or shadows on the Moon, following the rotation of Saturn, Jupiter or Mars, or looking for the colors of stars. The color images often are not "true" color but a combination of different filters to highlight some aspects of the objects of interest.  You can make them too by working with the original data.
 +
 
 +
Except for the special wide field cameras, these telescopes cover a field less than about half a degree across, the apparent size of the Moon. Each pixel resolves about 0.5 arcsecond (there are 3600 arcseconds in a degree), and measures how much light arrived at that spot in the image for the duration of the exposure. By comparing one pixel with another, you can tell how much brighter or fainter one feature of the image is compared to another. The image that you see, while visually exciting, is also a tool to measure how much light there is and where it is.
 +
 
 +
Some images may be returned to you with a calibration for the position in the sky, and as you explore them you can measure the celestial coordinates of any point in the image. In this way, you can identify individual stars, clusters, nebulae, and galaxies in the images. You can follow the changing positions of asteroids and satellites of planets. You can spot a new supernova, watch variable stars, measure the separation of double stars, measure the diameter of a distant galaxy, or follow a new comet.
 +
 
 +
 
  
Some images may be returned to you with a calibration for the position in the sky, and as you explore them you can measure the celestial coordinates of any point in the image. In this way, you can identify individual stars, clusters, nebulae, and galaxies in the images. You can follow the changing positions of asteroids and satellites of planets. You can spot a new supernova, watch variable stars, measure the separation of double stars, measure the diameter of a distant galaxy, or identify a new comet. However, most images are returned without calibrated positions, and you will have to compare them to web-based resources to understand what you have recorded.
+
== Filters, Sensitivity, and Spatial Resolution ==
  
  
With the scientific cameras on the CDK20 telescopes each image is taken through a filter that isolates a narrow band of the spectrum. If you looked through one of them, you would see a blue, green, or red scene. Here’s how we designate the filters that are usually available:
+
With the scientific cameras each image is taken through a filter that isolates a narrow band of the spectrum by passing the light through a filter that removes all but the part we want to record.   If you looked through one of the filters, you would see only part of the light that is collected by the telescope.  A "blue" filter would should light our eyes sense as blue, while an "infrared" filter would should light our eyes cannot see at all. Here’s how we designate the filters that are usually available by the wavelengths they transmit:
  
 
* Blue-Green: g' (400 to 530 nm)
 
* Blue-Green: g' (400 to 530 nm)
Line 46: Line 70:
 
* Infrared: z' (825 1100 nm)
 
* Infrared: z' (825 1100 nm)
  
The numbers are the wavelength of light in the spectrum, from blue light at 450 nanometers (nm) to red light at 650 nm (nm). Infrared has a longer wavelenth than red, and ultraviolet has a shorter wavelength than blue. Our telescopes respond well to "near" infrared light, out to 1100 nm, but not well to ultraviolet light.
 
  
A measurement with different filters allows us to determine the “color” of a star, or we can put images from blue, green, and red together to make a color image that will resemble what you would see if your eyes could detect this faint light. Images  through a filter that isolates light emitted by hydrogen gas would show few stars, and if you could "see" through this filter the scene would look dark red and show only the gas. You may read about all the filters that are available [http://www.astro.louisville.edu/mediawiki/index.php/Filters here].
+
The numbers are the wavelength of light in the spectrum, from blue light at 450 nanometers (nm) to red light at 650 nm (nm). Infrared has a longer wavelength than red, and ultraviolet has a shorter wavelength than blue. Since our telescopes respond well to "near" infrared light, out to 1100 nm, but not well to ultraviolet light, we observe in the bands that are most efficiently detected by the optics and electronics.  
  
The special "live" C14 telescope uses a very high quality color CCD camera and provides images immediately in full color, much as you would do with your own digital camera or cell-phone camera. This color camera is excellent for comparing light in different filter bands. Short exposures with this camera show hints of color on the Moon, fine detail in the atmosphere of Jupiter and Saturn, and hints of features on Mars.
+
A measurement with different filters allows us to determine the “color” of a star, or we can put images from blue, green, and red together to make a color image that will resemble what you would see if your eyes could detect this faint light. Images  through a filter that isolates light emitted by hydrogen gas would show few stars, and if you could "see" through this filter the scene would look dark red and show only the gas. You may read more about all the filters that are available here.
  
The faintest stars you will find are about 18th magnitude. These stars are more than 10,000,000 times fainter that the brightest stars in the night sky. If the air is steady, the smallest detail you will see is about 1 arcsecond across. For comparison, Jupiter appears about 40 arcseconds across in our sky, and the Andromeda galaxy extends thousands of arcseconds. Due to a limitation on the shortest exposure we can take, stars brighter than about 3rd or 4th magnitude are too bright to record except with the full color camera on the C14 telescope.
+
The faintest stars you will find in most images are about 18th magnitude. These stars are more than 10,000,000 times fainter that the brightest stars in the night sky. Typically the telescoped cover a field of about 1/2 degree, the diameter of the full Moon, but in some cases it can be smaller to see very fine detail,or larger, to get an entire constellation or a big comet. If the air is steady, the smallest detail you will see is about 1 arcsecond across. For comparison, Jupiter appears about 40 arcseconds across in our sky, and the Andromeda galaxy extends thousands of arcseconds. Some of our planetary and lunar images show detail as small as  0.3 arcseconds, the resolution limit of our telescopes in perfectly stable air.
 +
 
 +
 
 +
== Objects ==
  
 
Within our solar system you could expect to see
 
Within our solar system you could expect to see
  
* changing phases of the Moon, and its libration  
+
* Solar System
* craters on the Moon and shadows that move during the night
+
** the occasional bright comet and many very faint ones
* "earthshine", the light on the dark side of the Moon reflected from Earth
+
** changing phases of the Moon, and its libration
* Venus, Mars, Jupiter, Saturn, Uranus and Neptune moving nightly across the sky with respect to stars
+
** craters on the Moon and shadows that move during the night
* polar caps and large features on Mars
+
** "earthshine", the light on the dark side of the Moon reflected from Earth
* satellites of Jupiter, Saturn, Uranus and Neptune moving nightly
+
** Venus, Mars, Jupiter, Saturn, Uranus and Neptune moving nightly across the sky with respect to stars
* changing atmospheric features on Jupiter and Saturn
+
** polar caps and large features on Mars
* rings of Saturn
+
** satellites of Jupiter, Saturn, Uranus and Neptune moving nightly
* asteroids
+
** changing atmospheric features on Jupiter and Saturn
* the brighter dwarf planets
+
** rings of Saturn
 +
** asteroids
 +
** the brighter dwarf planets like nearby Ceres and distant Pluto
  
 
Within our Milky Way galaxy you could see
 
Within our Milky Way galaxy you could see
  
* star birth nebulae
+
* Galactic
* open clusters of young stars
+
** star birth nebulae
* active stars that erupt and change brightness
+
** open clusters of young stars
* double stars in orbit around one another (but not so fast that you would see the motion) unless you come back several years later
+
** active stars that erupt and change brightness
* planetary nebulae surrounding dying stars
+
** double stars in orbit around one another (but not so fast that you would see the motion) unless you come back several years later
* globular clusters of very old stars
+
** variable stars that pulsate, and pairs of eclipsing binary stars that change their brightness periodically
 +
** stars moving slowly across the sky by comparing old and recent images
 +
** planetary nebulae surrounding dying stars
 +
** globular clusters of very old stars
  
 
Beyond our galaxy there are
 
Beyond our galaxy there are
  
* nearby companion galaxies like the Large and Small Magellanic Clouds
+
* Extragalactic
* clusters of galaxies like those in Virgo and Coma
+
** nearby companion galaxies like the Large and Small Magellanic Clouds
* active galaxies with blackholes in their nuclei
+
** clusters of galaxies like those in Virgo and Coma
* other fainter galaxies out to distances of over 100 million light years
+
** active galaxies with blackholes in their nuclei
* quasars out to distances of billions of light years
+
** other fainter galaxies out to distances of over 100 million light years
* the occasional new supernova in a distant galaxy
+
** quasars out to distances of billions of light years
 +
** the occasional new supernova in a distant galaxy
  
 
However, what is available to see depends on the time of year (where Earth is in its orbit), where the planets are in their orbits, and whether you are using a telescope in the northern or southern hemisphere.
 
However, what is available to see depends on the time of year (where Earth is in its orbit), where the planets are in their orbits, and whether you are using a telescope in the northern or southern hemisphere.
 +
 +
  
 
== How to Proceed ==
 
== How to Proceed ==
Line 92: Line 126:
 
If you are in the astronomy lab on campus and working in a small group (usually  3 students), you may make a decision as a group about what to request.  This is easiest for us too, since we have fewer requests to handle that way.  However, if you prefer you may work on your own too.
 
If you are in the astronomy lab on campus and working in a small group (usually  3 students), you may make a decision as a group about what to request.  This is easiest for us too, since we have fewer requests to handle that way.  However, if you prefer you may work on your own too.
  
You will have until the end of the semester to complete this exercise. However, it has two graded parts, and the first part you need to do immediately: define a problem and propose an observation. After that, we will help you to use  data with our telescopes, and assist you with understanding what it has to offer.
+
This project has two parts that are graded separately. The first part you need to do this week is to  define a problem and propose an observation. After that, we will find data for you in our archive, or even acquire data with our telescopes over the following weeks.  Once we have something useful, we will provide it to you and, where you need it,  assist you with understanding what it has to offer. Our expectation is to have data back to you in early April, and the last activity of this semester will be to tell us what you can find in it.  When the data are available there will be an announcement, probably a comment on the discussion forum, and the last activity page will open up on the class website too.
  
Begin by asking yourself
+
* Step one: Decide What to Observe
  
  
<center>
+
The first big step is to decide what you would like to do.  Almost always, this is a very challenging exercise because there is so much to chose from.  There is no right answer.  Here is a guide to help you think about it.  Also, before submitting your request, we welcome a discussion on line or email if you need advice.
'''''What would I like to know more about that I could expect to “see” with one of these telescopes?'''''</center>
 
  
 +
'''What would I like to know more about that I could expect to “see” with one of these telescopes?'''
  
With that in mind satisfy your curiosity by selecting an object and the sort of data you would like to have on it. Check that the objects of interest are visible to us now, and complete the simple form at this website:
+
Our telescopes  can provide data allowing you to measure how stars vary in brightness ("variable stars"),  to follow the motions of satellites of Jupiter, Saturn, Uranus, and Neptune,  track asteroids, and capture the latest new supernova or recently discovered comet. When the skies are dark and the Moon is not out, they can record faint nebulae and distant galaxies too.  We offer views of the clouds of Jupiter and the rings and atmosphere of Saturn in better detail by selecting the very best images that are not blurred by Earth's atmosphere.  Our wide field telescopes show faint nebulae and star clusters that span several degrees on the sky.
  
<center> [https://docs.google.com/spreadsheet/viewform?formkey=dGlxdXE5WVBmMlpjUV94VEVPR3JyQ3c6MA Telescope Use Request Form] </center>
+
Use your imagination!! Satisfy your curiosity by selecting an object or objects, and the sort of data you would like to have on it. Once you have made a decision, you have to submit your request so that we know what you want, and you have to answer questions about your request.
  
Answer the questions on this form as best you can. There is no correct answer, but if needed we will ask for additional information to be sure we can supply data that are interesting and useful.  The form asks for a contact email, and you may supply one or more names.  You do not have to submit a request for each person in the group, just for the group as a whole.
 
  
After you have done that, then each student should answer these questions in the lab and give them to the lab assistant.  He may have an immediate suggestionRemember that we need both the answers from you on the usual lab sheet, and the completed group web form while you are in class today.
+
First, check that the object of interest is  visible to us now unless you want what we already have.  Indeed, our best planetary images are ones we have selected from among thousands taken, so even if a planet is not favorably placed now we can probably offer something.  However currently the choices in our own solar system are
  
== Questions ==
+
* Observable Solar System Objects
 +
** Venus, still visible in the evening sky and rapidly moving closer and in line with the Sun. 
 +
** Jupiter, visible in the morning sky, and increasingly well placed to observe as we go into the spring season, has beautiful bands and changing detail, as well as bright satellites.
 +
** Moon, as always, spectacular in detail and visible to us almost any night with various craters, mountains and mare
 +
** An occasional comet.  Ones close to the sun and bright are difficult to work with, but fainter ones with obscure names that do not make the news are almost always around
 +
** Bright asteroids.  Since there are thousands we have orbits for, there are always many we can follow as they move.  Of course no detail is observable with a telescope.
  
''1What is the name of the object you have selected? ''
+
You might use Stellarium, for example, to see what is in the sky now and later this spring, or the on-line tool [http://n-the-sky.org n-the-sky.org].  [http://www.sky-map.org/ Sky-Map] and [http://aladin.u-strasbg.fr/AladinLite/ Aladin-Lite]  will let you explore images and data from professional observatories on the web. You could also use Google simply to search for more information about your proposed target. If your request is inappropriate for what we can do, we will work with you to help refine your selection.
  
''2. What sort of object is it? Simple answers are a planet, a dwarf planet, an asteroid, Earth's Moon, a star ... ''
+
We will  make the selection of the telescope and other resources for you based on what you tell us about your request. For example, if it is well below the celestial equator and seen only in the southern hemisphere we will use a telescope at Mt. Kent, and if it is better seen from the northern hemisphere, we will use one of  the telescopes at Moore Observatory in Kentucky. The Moon, Jupiter and Saturn are best recorded with the special purpose planetary telescope at Moore Observatory.  Objects that cover a wide area of sky may be better seen in the wide field telescope or even the color cameras, but most requests will be directed to the 20-inch "CDK" telescopes. You are welcome to request a specific telescope and if it is available and appropriate we will try to use it for your data.
  
''3.  How bright is it?  Give its magnitude if that is relevant.  You can find this usually on the web (Wikipedia is quite reliable for this), or in Stellarium (or XEphem on the computers in the astronomy lab room).  Just to remind you, the brightest stars are 0th magnitude, the faintest you can see without  a telescope is about 6th magnitude, and the faintest our telescopes can see is about 18th magnitude.  The Moon and nearby planets are of course much brighter than the brightest stars. ''
 
  
''4. How large is it in degrees, arcminutes, or arcseconds (as appropriate)? The smallest detail our telescopes can record is about 1 arcsecond, and the field of view is
+
* '''Step 2: Register Your Request'''  
about 1/2 degree.''
 
  
''5. What is its  declination (north is +, south is -) of the object?  ''
+
Complete the simple form at the link below.
  
''6. Do you need a southern telescope to see it?  If it is below -10 degrees we cannot do it well from our northern telescopes. The absolute limit for us is -52 degrees but that puts the object on the southern horizon for a few seconds!  We have limited time this semester for new data from Mt. Kent and planetary imaging will be done from Moore Observatory.''
+
[http://www.astro.louisville.edu/moorerequests Telescope Use Request Form] at [http://www.astro.louisville.edu/moorerequests http://www.astro.louisville.edu/moorerequests]
  
''7. What is its right ascension (in hours from 0 to 24, with minuts and seconds)? We can see objects between 3 and 20 hours this month because the Sun blocks out part of the sky. ''
+
We use your responses to schedule our telescopes, so please complete it  while you are in the lab. Make a note to yourself of your request, and keep some notes about what you responded since they will help you complete the second part later. If you are working with others we only need one on-line request. In the comments section, if you note who is working together it will simplify sorting out the requests and responses later.
  
''8. At what time in late March or April will this object be will above the horizon seen from the observatory you have chosen? ''
 
  
''9. What would you like to know more about that you could expect to “see” with the images from a telescope? This is the hard part!''
 
  
''10.  What last name and email address do you want us to use to provide you with instructions on where to find your data?  ''
 
  
== Limitations ==
+
For this lab we need the following from each student.
  
The one necessary part of this request is that you have to select an object that is observable with our telescopes. You might use [http://www.stellarium.org/ Stellarium], for example, to see what is currently visible, and [http://www.sky-map.org/ Sky-Map] to explore images and data on the web. You could also use Google simply to search for more information about your proposed target. If your request is inappropriate, we will work with you to help refine your selection. However, once you have data, one of the questions you will have to answer is why you made this choice, and what you expect to learn from it.
 
  
This fall from Moore Observatory we are able to observe the entire sky north of -10 degrees Declination and from Right Ascension 4 hours to 20 hours, between March 20 and April 20.   This includes Saturn, Jupiter, Mars, the Moon, and Venus:
+
* '''Step 3: Respond on the Answer Sheet for This Lab."'''
 +
** Object you have selected by an identification we can use with the telescopes.
 +
** A brief statement of what that object is.
 +
** Where is it in the sky?  Correct celestial coordinates are an ideal response.
 +
** Is it observable now during the night from either southern or northern hemispheres.
 +
** Which telescope do you think would be useful for this. Explain your answer, or if you do not know which telescope, tell us what would affect the choice of telescope based on your choice of object.
 +
** Provide a concise statement of what you expect to learn about your selected object from whatever data we can offer.
 +
** Your preferred email address so that we can respond to you if needed
 +
** The names of the other students working with you on the same object
  
* New Moon on March 22
+
For this lab it will help us a lot if you put your '''preferred email address''' on the form you submit to the assistant, and list the names of those who are working with you on this.  Should groups re-organize later in the semester or you find your self working with someone else, this will insure we can get data to you.
* First quarter on March 29
 
* Full Moon on April 6
 
* Last quarter on April 13
 
* New Moon on April 21
 
  
Our opportunities to see the southern sky from Mt. Kent Observatory are more limited because of technical improvements being installed on our telecopes, but we may be able to provide new images of parts of the Milky Way not seen from the northern hemisphere, and the Large and Small Magellanic clouds. From Mt. Kent we can observe declinations below +20 all the way to the south celestial pole.
+
After you have submitted the request, then each student should  answer the questions asked here on the usual lab response form and  give them to the lab assistant.    He may have an immediate suggestion about your choice and you probably should discuss it with him before you get to this last stepRemember that we need both the answers from you on the usual lab sheet, and the completed web submission from your group while you are in class today.
  
Once your data are available we will provide a link from which you can download images and there will be another unit posted  for you to use in completing the work. This is the simplest process since it does not depend on coordinating your schedule with the telescope and weather. It is available for any of the telescopes we have in operation this semester.
 
  
If you would like an opportunity to operate the "live" telescope at Moore Observatory and take images of your own, please note that. We may offer this for planets and the Moon in the northern sky, but we have to schedule the use and coordinate with you so that you can be at your computer when it is dark and clear at the observatoryUsually we would assist you at the same time by a Skype session, email chat, or a phone call.
+
== What Happens Later ==
 +
 +
 +
Once your data are available we will provide a link from which you can download images and there will be another activity in class  for you to use in completing the workExpect it in early April, or before if the weather is good to us.

Latest revision as of 21:58, 13 February 2017

Remote Telescope Data

Today’s computer technology, modern optics, and electronics allow astronomers and students to "see" the sky without enduring long freezing nights looking through an eyepiece. The data we acquire are quantitative measurements of how much light arrives from fields of view that can be tiny and cover only a few stars, or vast, and cover constellations. They can tell you the positions of moving objects, the variations in their brightness, their colors, details of the structure, and how they interact or relate with nearby companions. Modern astronomy is evolving in the development of a new class of very large telescopes that by mid-2020's will have public data over the entire sky updated almost nightly. Smaller telescopes and instruments in space follow up on the discoveries offered by these big telescopes with closer inspection and careful analysis.

If you are interested in this future world, you can read more at websites for Gaia, a new satellite beginning to return amazing measurements of distances throughout our own galaxy, and of LSST, a "synoptic survey" telescope under construction in Chile.


The University of Louisville and the University of Southern Queensland operate remotely controlled telescopes at Moore Observatory near Brownsboro, Kentucky, at Mount Kent Observatory near Toowoomba, Australia, and on Mt. Lemmon in Arizona. For more than 10 years we have been acquiring data for research and student use, and we have an archive of many of the bright objects that may interest you. This semester our telescopes in Kentucky, Arizona, and Australia are operating robotically under the supervision of professional astronomers and can also acquire new images to meet your requests as well.

This week your lab activity is to thoughtfully identify something in the sky that really grabs your interest. It can be anything, but because there are limitations on what we can observe we will make a few suggestions to guide your thoughts. With that, ask some questions yourself -- we are reversing roles here! Why would you like to see this object, and what would you like to learn about it that a telescope image or measurement could reveal?


Available Resources

The observatories are described on our website at

http://sharedskies.org


and you are encouraged to explore it to see about the observatories and their telescopes. The content is currently under development, and may change during the semester.

The facilities we have access to include:

  • Moore Observatory in the northern hemisphere near Brownsboro, Kentucky
  • Mt. Kent Observatory in the southern hemisphere near Toowoomba, Australia
  • Mt. Lemmon Observatory in Arizona, near Tucson


At both observatories we have identical 0.5 meter (20 inch) diameter "CDK20" research telescopes operating with a CCD camera and a selection of filters. These are the primary telescopes for this program. We offer other instruments too, and we are developing the capability to have you visit us through the web when the telescopes are in operation and to press the "shutter button" yourself. For example there are

  • A fast wide field Shared Skies Live telescope at Moore Observatory to take images of stars and nebulae through special filters.
  • A special long-focus telescope at Moore Observatory to take images of planets
  • Color cameras to quickly image star patterns, constellations, or comets that may span many degrees.
  • Two 0.6 meter (24 inch) "RC24" research telescope at Moore Observatory and Mt. Lemmon are used primarily to study planets around other stars
  • A 0.7 meter (27 inch) "CDK700" telescope at Mt. Kent observatory that will be used for spectroscopy, the analysis of starlight, for assisting the new NASA TESS satellite that is to launch soon.


Also we have a substantial improving archive of the best images that we add to often. We will draw from it when we can to satisfy your requests.


What the Telescopes Can Show

Except the color cameras used to record wide field images of constellations and the occasional comet, the CCD cameras on the telescopes return scientific images as digital files in “FITS” format. These images may be viewed in your computer's browser with some tools we will provide, or with other software you load on your own computer. those images require some effort to analyze, but they offer quantitative data on positions and brightnesses. Over the next few weeks you will be using some of the software that is needed and gain experience with what it can do.

In many cases we will produce color images from these data that may be useful if you are interested in seeing form or structure, watching craters or shadows on the Moon, following the rotation of Saturn, Jupiter or Mars, or looking for the colors of stars. The color images often are not "true" color but a combination of different filters to highlight some aspects of the objects of interest. You can make them too by working with the original data.

Except for the special wide field cameras, these telescopes cover a field less than about half a degree across, the apparent size of the Moon. Each pixel resolves about 0.5 arcsecond (there are 3600 arcseconds in a degree), and measures how much light arrived at that spot in the image for the duration of the exposure. By comparing one pixel with another, you can tell how much brighter or fainter one feature of the image is compared to another. The image that you see, while visually exciting, is also a tool to measure how much light there is and where it is.

Some images may be returned to you with a calibration for the position in the sky, and as you explore them you can measure the celestial coordinates of any point in the image. In this way, you can identify individual stars, clusters, nebulae, and galaxies in the images. You can follow the changing positions of asteroids and satellites of planets. You can spot a new supernova, watch variable stars, measure the separation of double stars, measure the diameter of a distant galaxy, or follow a new comet.


Filters, Sensitivity, and Spatial Resolution

With the scientific cameras each image is taken through a filter that isolates a narrow band of the spectrum by passing the light through a filter that removes all but the part we want to record. If you looked through one of the filters, you would see only part of the light that is collected by the telescope. A "blue" filter would should light our eyes sense as blue, while an "infrared" filter would should light our eyes cannot see at all. Here’s how we designate the filters that are usually available by the wavelengths they transmit:

  • Blue-Green: g' (400 to 530 nm)
  • Yellow-Red: r'(530 to 700 nm)
  • Hydrogen: H-alpha (656 nm)
  • Red-Near Infrared: i' (700 to 825 nm)
  • Infrared: z' (825 1100 nm)


The numbers are the wavelength of light in the spectrum, from blue light at 450 nanometers (nm) to red light at 650 nm (nm). Infrared has a longer wavelength than red, and ultraviolet has a shorter wavelength than blue. Since our telescopes respond well to "near" infrared light, out to 1100 nm, but not well to ultraviolet light, we observe in the bands that are most efficiently detected by the optics and electronics.

A measurement with different filters allows us to determine the “color” of a star, or we can put images from blue, green, and red together to make a color image that will resemble what you would see if your eyes could detect this faint light. Images through a filter that isolates light emitted by hydrogen gas would show few stars, and if you could "see" through this filter the scene would look dark red and show only the gas. You may read more about all the filters that are available here.

The faintest stars you will find in most images are about 18th magnitude. These stars are more than 10,000,000 times fainter that the brightest stars in the night sky. Typically the telescoped cover a field of about 1/2 degree, the diameter of the full Moon, but in some cases it can be smaller to see very fine detail,or larger, to get an entire constellation or a big comet. If the air is steady, the smallest detail you will see is about 1 arcsecond across. For comparison, Jupiter appears about 40 arcseconds across in our sky, and the Andromeda galaxy extends thousands of arcseconds. Some of our planetary and lunar images show detail as small as 0.3 arcseconds, the resolution limit of our telescopes in perfectly stable air.


Objects

Within our solar system you could expect to see

  • Solar System
    • the occasional bright comet and many very faint ones
    • changing phases of the Moon, and its libration
    • craters on the Moon and shadows that move during the night
    • "earthshine", the light on the dark side of the Moon reflected from Earth
    • Venus, Mars, Jupiter, Saturn, Uranus and Neptune moving nightly across the sky with respect to stars
    • polar caps and large features on Mars
    • satellites of Jupiter, Saturn, Uranus and Neptune moving nightly
    • changing atmospheric features on Jupiter and Saturn
    • rings of Saturn
    • asteroids
    • the brighter dwarf planets like nearby Ceres and distant Pluto

Within our Milky Way galaxy you could see

  • Galactic
    • star birth nebulae
    • open clusters of young stars
    • active stars that erupt and change brightness
    • double stars in orbit around one another (but not so fast that you would see the motion) unless you come back several years later
    • variable stars that pulsate, and pairs of eclipsing binary stars that change their brightness periodically
    • stars moving slowly across the sky by comparing old and recent images
    • planetary nebulae surrounding dying stars
    • globular clusters of very old stars

Beyond our galaxy there are

  • Extragalactic
    • nearby companion galaxies like the Large and Small Magellanic Clouds
    • clusters of galaxies like those in Virgo and Coma
    • active galaxies with blackholes in their nuclei
    • other fainter galaxies out to distances of over 100 million light years
    • quasars out to distances of billions of light years
    • the occasional new supernova in a distant galaxy

However, what is available to see depends on the time of year (where Earth is in its orbit), where the planets are in their orbits, and whether you are using a telescope in the northern or southern hemisphere.


How to Proceed

If you are in the astronomy lab on campus and working in a small group (usually 3 students), you may make a decision as a group about what to request. This is easiest for us too, since we have fewer requests to handle that way. However, if you prefer you may work on your own too.

This project has two parts that are graded separately. The first part you need to do this week is to define a problem and propose an observation. After that, we will find data for you in our archive, or even acquire data with our telescopes over the following weeks. Once we have something useful, we will provide it to you and, where you need it, assist you with understanding what it has to offer. Our expectation is to have data back to you in early April, and the last activity of this semester will be to tell us what you can find in it. When the data are available there will be an announcement, probably a comment on the discussion forum, and the last activity page will open up on the class website too.

  • Step one: Decide What to Observe


The first big step is to decide what you would like to do. Almost always, this is a very challenging exercise because there is so much to chose from. There is no right answer. Here is a guide to help you think about it. Also, before submitting your request, we welcome a discussion on line or email if you need advice.

What would I like to know more about that I could expect to “see” with one of these telescopes?

Our telescopes can provide data allowing you to measure how stars vary in brightness ("variable stars"), to follow the motions of satellites of Jupiter, Saturn, Uranus, and Neptune, track asteroids, and capture the latest new supernova or recently discovered comet. When the skies are dark and the Moon is not out, they can record faint nebulae and distant galaxies too. We offer views of the clouds of Jupiter and the rings and atmosphere of Saturn in better detail by selecting the very best images that are not blurred by Earth's atmosphere. Our wide field telescopes show faint nebulae and star clusters that span several degrees on the sky.

Use your imagination!! Satisfy your curiosity by selecting an object or objects, and the sort of data you would like to have on it. Once you have made a decision, you have to submit your request so that we know what you want, and you have to answer questions about your request.


First, check that the object of interest is visible to us now unless you want what we already have. Indeed, our best planetary images are ones we have selected from among thousands taken, so even if a planet is not favorably placed now we can probably offer something. However currently the choices in our own solar system are

  • Observable Solar System Objects
    • Venus, still visible in the evening sky and rapidly moving closer and in line with the Sun.
    • Jupiter, visible in the morning sky, and increasingly well placed to observe as we go into the spring season, has beautiful bands and changing detail, as well as bright satellites.
    • Moon, as always, spectacular in detail and visible to us almost any night with various craters, mountains and mare
    • An occasional comet. Ones close to the sun and bright are difficult to work with, but fainter ones with obscure names that do not make the news are almost always around
    • Bright asteroids. Since there are thousands we have orbits for, there are always many we can follow as they move. Of course no detail is observable with a telescope.

You might use Stellarium, for example, to see what is in the sky now and later this spring, or the on-line tool n-the-sky.org. Sky-Map and Aladin-Lite will let you explore images and data from professional observatories on the web. You could also use Google simply to search for more information about your proposed target. If your request is inappropriate for what we can do, we will work with you to help refine your selection.

We will make the selection of the telescope and other resources for you based on what you tell us about your request. For example, if it is well below the celestial equator and seen only in the southern hemisphere we will use a telescope at Mt. Kent, and if it is better seen from the northern hemisphere, we will use one of the telescopes at Moore Observatory in Kentucky. The Moon, Jupiter and Saturn are best recorded with the special purpose planetary telescope at Moore Observatory. Objects that cover a wide area of sky may be better seen in the wide field telescope or even the color cameras, but most requests will be directed to the 20-inch "CDK" telescopes. You are welcome to request a specific telescope and if it is available and appropriate we will try to use it for your data.


  • Step 2: Register Your Request

Complete the simple form at the link below.

Telescope Use Request Form at http://www.astro.louisville.edu/moorerequests

We use your responses to schedule our telescopes, so please complete it while you are in the lab. Make a note to yourself of your request, and keep some notes about what you responded since they will help you complete the second part later. If you are working with others we only need one on-line request. In the comments section, if you note who is working together it will simplify sorting out the requests and responses later.



For this lab we need the following from each student.


  • Step 3: Respond on the Answer Sheet for This Lab."
    • Object you have selected by an identification we can use with the telescopes.
    • A brief statement of what that object is.
    • Where is it in the sky? Correct celestial coordinates are an ideal response.
    • Is it observable now during the night from either southern or northern hemispheres.
    • Which telescope do you think would be useful for this. Explain your answer, or if you do not know which telescope, tell us what would affect the choice of telescope based on your choice of object.
    • Provide a concise statement of what you expect to learn about your selected object from whatever data we can offer.
    • Your preferred email address so that we can respond to you if needed
    • The names of the other students working with you on the same object

For this lab it will help us a lot if you put your preferred email address on the form you submit to the assistant, and list the names of those who are working with you on this. Should groups re-organize later in the semester or you find your self working with someone else, this will insure we can get data to you.

After you have submitted the request, then each student should answer the questions asked here on the usual lab response form and give them to the lab assistant. He may have an immediate suggestion about your choice and you probably should discuss it with him before you get to this last step. Remember that we need both the answers from you on the usual lab sheet, and the completed web submission from your group while you are in class today.


What Happens Later

Once your data are available we will provide a link from which you can download images and there will be another activity in class for you to use in completing the work. Expect it in early April, or before if the weather is good to us.