Getting Started
Welcome to the SkyServer tools pages!
SkyServer's tools allow you to access all publicly available data
from the Sloan Digital Sky Survey, one of the largest surveys of the night
sky ever made. You can use SDSS data to learn about the way the universe
works, or even to do original scientific research!
The Getting Started pages will tell you what types of data are
available on SkyServer, and which tools are best for accessing which types
of data. These tools give you many different ways
of looking at our data. Some tools also have help pages that will give you
more specific information on how to use the tool.
Types of Data
SkyServer offers access to many different types of data, but
most users will usually focus on four types: images,
spectra, photometric data, and spectroscopic data. The table below shows
what each type of data means:
Images |
 |
Pictures of celestial objects, stored as .jpg or .fits files |
Spectra |
 |
Graphs of the amount of light emitted by an object at different
wavelengths. Spectra can be used to study the compositions and temperatures
of objects, as well as their distances from Earth. |
Photometric Data |
 |
Various quantities measured from an object's image, such as its
brightness or size |
Spectroscopic Data |
 |
Various quantities measured from an object's spectrum, such as
its spectral type or redshift. |
To learn about the other types of data available on SkyServer, read
through the Object Browser.
Tools
The table below gives a short description of each of SkyServer's tools,
listed from the most simple and general to the most complex and specialized.
The table also shows when you might use each tool, based on what information
you know already and what information you want to find out. Click on the name of
a tool for more information on what it does and how to use it.
Tool |
What it Does |
Use it when... |
Famous Places |
Presents a gallery of beautiful images from the SDSS, with
links to information on each object. |
you want to see a few beautiful images SDSS has taken. |
Scrolling Sky |
Lets you enjoy the sight of the sky as the SDSS telescope
sees it when scanning along its nightly cycle. |
you want to see how the sky looks to the SDSS telescope. |
Navigate |
Lets you navigate through the sky by panning and zooming. When you
click on an object, you get a summary of its photometric data. You can also
save objects in a notebook and export them to a spreadsheet program
for later analysis. |
you are looking through the sky for objects to study. |
Explore |
Lets you look up all photometric and spectroscopic data for
individual objects. |
you know an object's ID or position and you want to look up
its data. |
Get Images |
Lets you download images (of fields and mosaics) and spectra
(organized by spectrum and SDSS plate). |
you know the SDSS run-camcol-field or stripe-mosaic number of
an image, or the plate-spectrum number of a spectrum, and you want to look at
or download the image or spectrum. |
Search |
Lets you search the database for objects near to a certain
sky position (in radial or rectangular coordinates) or with certain
brightnesses. |
you want to find all objects in one part of the sky. |
SQL Search |
Lets you search the database for all objects that meet any criteria
you can think of, then returns whatever photometric or spectroscopic
data you request. The SQL search tool is the most powerful tool on SkyServer;
professional astronomers use a very similar tool in their research. |
you want to answer a specific astronomical research question
quickly. |
Cross-ID |
Lets you upload a list of sky positions, then returns a list
of all SDSS objects near those positions. |
you have a list of sky objects from another astronomical
database, and you want to find all SDSS objects near each of your
objects. |
Other Resources
Documentation gives you information that
will help you use the SDSS database to write queries in the Query tool.
The Object Browser tells you what each item in the database means.
Download lets you download other
SkyServer documentation (papers that explain the data in much more detail) and
tools such as SkyQA, a Java-based advanced query tool.
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