Follow Us
|
Copernicus Search Help
There are two search pages for Copernicus data: the Raw Data Search page and the Coadded Scan Search page. Since most of the search fields are identical on the two pages, this help page applies to both.
The search pages basically contain 3 parts. The top of the page lists the input search fields. Entering values (as described below) for one or more of these fields will define the selection criteria for the database search. The middle of the form contains buttons to initiate various actions including:
- perform the search using the specified search criteria and output format,
- clear the search form and reset values to the original defaults,
- reset entries to the set of (default) values used the previous time the search page was drawn, and
- display this help page.
After selecting search criteria, output options, and clicking the search button, a second page will appear listing the returned database entries. From this table, one may click on the object name to either display the FITS header for a raw data search, or display a plot of coadded counts versus wavelength for a coadded scan search. Clicking on the filenames for either catalog will download the selected FITS file.
- Target Name
- The name of the astronomical object you want to search for.
Examples of valid names include ZETA OPH, JUPITER, and HD 14633.
The object names were obtained from the Princeton University Observatory,
presumably as specified by the observer.
The Target Name specification field may be used with the resolver option. If the NED or SIMBAD resolver option is chosen, the name will be sent to that service, resolved if possible, coordinates returned. Those coordinates will be used to perform a search.
If you choose the "Don't resolve" option, no resolver is called and a string search will be executed using the target name entered.
When you search on the object name in the database, case will be ignored. The object name will not be wildcarded at the front and back (that's so if you innocently enter IO, you don't match things like ORION). You can wildcard the object name using *, however (for example, *IO*). You can also enter a comma-separated list; for example, *JUP*,*SAT* would match object names containing either JUP or SAT.
- The name resolver will let you resolve an object name into its coordinates. This is useful particularly for searching for objects that may be known by different names. resolved coordinates in place. If you don't elect to to resolve the object name, the Copernicus database will be searched on the object name given.
To resolve an object name, enter the object name in the Target Name field, select SIMBAD for the resolver, and click on the Search button. SIMBAD is the Set of Identifications, Measurements, and Bibliography for Astronomical Data at the Centre de Données astronomiques in Strasbourg, France.) The object name will be sent to SIMBAD, which will send back the coordinates. (If the object name is not recognized by the resolver, or there is some other problem with the SIMBAD service, then the search form will be redrawn with an error message at the top.) These coordinates will then be used to search the Copernicus database, along with whatever other query qualifications you have given.
We recommend that you use object name resolution to find observations of specific object in the database. This is the most reliable way to look up observations, because the observer could have given any object name at all (for example, NGC1976 instead of M42). However, if you do know the object name that the observer used, you can select Don't resolve, in which case the object name will not be resolved into coordinates, but will be used as a search qualification in the database. (This will happen only when you press the Search button.)
- The Right Ascension and Declination around which you want to search. A number of formats are accepted for the RA and Dec. Here are some examples:
Decimal Degrees 185.63325 29.8959861111111 Hours, minutes and Seconds 12 22 31.98 29 53 45.55 12h22m31.98s 29d53m45.55s 12:22:31.98 +29:53:45.55 12h22'31.98" 29d53'45.55" 12h 22m 31.98s 29d 53m 45.55s 12h 22' 31.98" 29d 53' 45.55" 12h 22' 31.98" -29d 53' 45.55" 12h22'31".98 -29d53'45".55 12h22m31s.98 -29o53m45s.55 12h 22' 31".98 -29d 53' 45".55 Hours/Degrees and Minutes (no seconds) 12 22 29 53 12h22m +29d53m 12h22m 29d53m 12:22m 29:53m 12h22' 29d53' 12h 22m 29d 53m 12h 22' 29d 53' 12h 22' -29d 53' The RA may be given in decimal degrees by indicating a D or d after the degrees: 12d 22m 29d 53mSpacing is not important, as long as the value is unambiguous, and that you delimit the hours/degrees, minutes, and (optional) seconds with letters, colons, spaces, or any character that's not a digit or a decimal point.Note also that seconds of the form 31".98 or 31s.98 are accepted. This should make it easy to cut and paste values into these fields from electronic publications.
- The radius of the search box around the RA and Dec, in floating-point arcminutes (e.g., 5.0). You should be careful about giving too restrictive a search radius in an Copernicus search. Note most of the coordinates contained in the Copernicus catalog were obtained from the Bright Star Catalog (BSC5).
- The equinox of the RA and Dec you have entered, either B1950 or J2000. This only affects the input coordinates; there is a separate selector for the equinox of the output coordinates.
If you hit the Resolve button to get an object's coordinates and redraw the form, the equinox will be set to J2000, since that's the equinox of the coordinates returned by the object name resolvers.
- The date and time, in GMT, on which the first exposure of a coadded scan was started. More precisely, it is the time in which the satellite crosses the longitude of the ascending node (LAN) for the orbit in which the earliest exposure was taken. (The actual start time is obtained by adding the FIRST SET time to the OBSERVATION TIME entry as described in Observation Time Correction .) The Copernicus satellite operated roughly from August, 1972 to February, 1981.
When specifying this date, you need to include at least a date; a time is optional. The date can have any of the following formats (the month name can be spelled out or abbreviated to three letters; case is not significant):
Jul 15 1994 Jul 1994 15 15 Jul 1994 1994 Jul 15 1994 15 Jul 7/15/1994 7-15-1994 7.15.1994If the day is omitted, the first day of the month is assumed. This means that a specification like "July 1994" will look for observations done on July 1 1994 00:00:00, not for observations done during July 1994. Note also that when entering a date with the month in numerical format, the American ordering is used; i.e., the first number is the month.If a time is omitted, then any time for that day will match. Otherwise, you can specify a time in any of these formats:
14:30 14:30:20 14:30:20:999 14:30:20.9 4am 4 PM 04:30:20 AMTo search for observations before a given date, use <, and for observations after a given date, use >. For example,> Jul 15 1994 < Jul 15 1994You can use the .. operator to search on a range of dates:Jul 1 1994 .. Aug 1 1995This operator is inclusive on the first date and exclusive on the second.Finally, you can search on a list of dates or date ranges. For example,
Jul 1 1994 .. Jul 3 1994, Dec 1 1995 .. Dec 6 1995will search for observations done within either one of these date ranges.- IUE Object class code. The IUE classification system used for categorizing Copernicus observations. The object class was originally specified by the IUE Guest Observer. Only those object classes appropriate for Copernicus observations are listed (i.e., classes 1 through 83). Note more than one object class can be specified for the search by clicking on multiple entries from the object class table.
- The minimum wavelength in the coadded scan, specified in Angstroms. Note coadded scan wavelengths are resampled to 0.01 Angstrom intervals.
- The maximum wavelength contained in the coadded scan, specified in Angstroms. Note coadded scans are resampled to 0.01 Angstrom intervals.
- Coadded scans have been generated for the U1 and U2 detectors. The U1 detector covers the 710-1500 A range at 0.05 A resolution, while U2 covers 750-1645 A at 0.2 A resolution.
Note the raw data sets contain data for all six detectors (i.e., u1,u2,u3,v1,v2,v3). V1 and V2 cover roughly the 1550-3200 A region at 0.1 and 0.4 A resolution respectively, while U3 and V3 are fixed in wavelength and used only for monitoring spacecraft pointing.
- The spectral type of the observed star as derived from the Yale Bright Star Catalog (YBS5). Generally the spectral type is a measure of the star's temperature. Spectral type is designated using the Morgan-Keenan spectral classification system, and is specified as one of ten letters (OBAFGKMRNS) followed by a number from 0 to 9 designating subdivisions. The hottest stars observed are generally around type O3. Only those spectral types found in the Copernicus catalog however, are listed in the seach page. Spectral type is not appropriate for non-stellar objects (e.g., galaxies, planets, etc.), so the field may be left blank. Note the returned catalog listing will display the full spectral classification including the spectral type and the luminosity class.
- The assigned file name. The raw data sets file names use the naming convention Cnnn.PEP where nnn is the 3-digit observation number assigned by Princeton Observatory describing the order in which targets were observed (i.e., the first observed target is named C001.PEP and the last target is C558.PEP).
The coadded scan file names are defined as Cnnn-###.ext where ### is a 3-digit number describing the order in which the scans were coadded (i.e., the maximum is 297), and ext is either .uu1 for unblocked u1 scans, .bu1 for blocked u1 scans, or .u2 for u2 scans.
Note wildcards can be used in the filename specification.
- You may now search on any column in the mission database. Select the field you wish to search on and type in the qualification. You may find the valid range of values by clicking on the field name. NOTE that if you choose a field in BOTH the form and in the User Option field, then you may not get results or the result you expect.
- You may choose the columns to be displayed in the output. A set of columns that are commonly requested has been chosen as a default.
The default set of columns is:
Mark Detector Filename Target Name RA (J2000) Dec (J2000) Npts Nscans Start Time Min Wavelength (Âle;) Max Wavelength (Âle;) start scan end scan Object Class ang sep(')You remove output columns by highlighting the column to be removed and then clicking on the remove button to the right of the list of chosen output columns.
You may determine the order of column placement by highlighting a column and then clicking on the up or down buttons to the right of the list of chosen output columns.
You may add a column to the list of chosen columns. Select the desired column on the pull down menu beneath the list of chosen output columns. Then click on the add button. The column will be added to the bottom of the output column list. <
You can select your own output columns by pressing the custom... radio button and selecting the columns from the list below it. The output columns will be in the order in which they appear in this list.
- Choose how you want the output rows sorted. You can select up to three fields to sort on. the rows will be sorted in the order of the first sort field; if two rows have the same sort field, they will be sorted in order of the second sort field, and so on.
For each field, you can select that the rows be sorted in reverse order on that field by selecting the reverse checkbox. For example, you can sort the rows with the most recent observations first by selecting Observation Date for the first sort field and selecting the reverse checkbox next to it.
- Some queries will be capable of returning thousands of rows or more. Such large search results tend to use up memory on both the client and server sides, and aren't usually useful. By default, we limit the number of rows displayed to 100 rows, but you can increase (or decrease) this limit as needed.
- Just what you'd think: the equinox of the coordinates displayed in the output.
- Select this checkbox if you want to see the SQL query that the Copernicus Search engine constructs from your query qualifications. The query will be shown at the end of the search results.
SQL (Standard Query Language, pronounced either "ess cue ell" or "sequel") is a language used used by most relational database systems for retrieving information from database tables. The Copernicus Search Page takes your search specifications and converts them to an SQL query to run on our database. Viewing the generated query is often useful for debugging, and may also be useful for SQL-literate users who want to see what logic was used in the query. (In fact, this may be useful for most people, since SQL is pretty easy to understand.)
- Select this checkbox if you want to have a set of distinct rows displayed. This is useful if you would like to see a distinct list of objects with certain criteria e.g. all the objects within an object class. To make this function useful, you should not select column names such as Data Id, Mark or Observation Date in as output columns as all output is considered when making rows distinct . Note that columns such as RA, Dec and Magnitude were defined by the IUE GO and often have different values for the s ame target name. If columns such as these are chosen as output columns, there will often be more than one row liste d per object name.
- You may choose one of three display options: HTML Form, a comma separated list, and Excel spreadsheet
- The name resolver will let you resolve an object name into its coordinates. This is useful particularly for searching for objects that may be known by different names. resolved coordinates in place. If you don't elect to to resolve the object name, the Copernicus database will be searched on the object name given.
 |
|
|
|
|
|
|
|
|
|