Search DASCH

Start searching the DASCH Plate Collection database using the instructions below. 

Search by Object

Object/Name Identifier: Keywords entered into the Object Name/Identifier field automatically gets searched in the SIMBAD Astronomical Database and the NASA/IPAC Extragalactic Database (NED). When the specified object is found, NED/SIMBAD's matching celestial coordinates will be returned and searched in our database. This is why a specified Object Name overrides any previously specified coordinates. Plates will be searched by these coordinates in which the celestial object lives, not necessarily the named Object. ___________________________________________________ Radius to extract: Choose a radius (in arcseconds) to search.   Date Range: We can also search according to a specified range of dates when the photographs were originally captured:
  • Starting Date (YYYY-MM-DD, or YYYY)
  • Ending Date (YYYY-MM-DD, or YYYY)
Search Scope: The image database, accessible at this link, includes several options to find glass plates, whether they've been scanned yet or not. At the bottom of the Search page, users can choose to search by the following:
  • only the unscanned plates,
  • only scanned plates,
  • the WCS Fitted Plates (Plates that have been scanned and have had their coordinates mapped to the positions of the sky) 
    • WCS Fitted Mosaic positions obtained after June 26, 2008 used tools provided by Astrometry.net.
  • the entire database of plates
___________________________________________________ Maximum results: Users may also narrow down the number of results they would like to retrieve from their search, by typing in the maximum number of plates they wish to see. Time Display: Select whether results should be displayed in Heliocentric Julian Time or UT Time. Coordinate Display: Choose to display the coordinates in sexigesimal (degrees, minutes, and seconds) or decimal (degrees). File Format: Choose whether images should be delivered in JPEG or FITS format. File Compression: Choose images to be delivered in TAR or ZIP files.

Search by Coordinates

Epoch: Choose whether the resulting coordinates should be referred to in terms of Besselian epoch (B1950), the previous standard, or the Julian epoch (J2000), the current standard. A star's right ascension and declination are always changing due to precession, so astronomers have to specify the date for which a right ascension and declination apply, with reference to a particular epoch.

Right Ascension & Declination: Search by celestial coordinates in the Right Ascension (HH.MM.SS.SSS) and Declination fields (DD.MM.SS.SSS).

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Radius to extract: Choose a radius (in arcseconds) to search.

Date Range: We can also search according to a specified range of dates when the photographs were originally captured:
  • Starting Date (YYYY-MM-DD, or YYYY)
  • Ending Date (YYYY-MM-DD, or YYYY)
Search Scope: The image database, accessible at this link, includes several options to find glass plates, whether they've been scanned yet or not. At the bottom of the Search page, users can choose to search by the following:
  • only the unscanned plates,
  • only scanned plates,
  • the WCS Fitted Plates (Plates that have been scanned and have had their coordinates mapped to the positions of the sky) 
    • WCS Fitted Mosaic positions obtained after June 26, 2008 used tools provided by Astrometry.net.
  • the entire database of plates
___________________________________________________ Maximum results: Users may also narrow down the number of results they would like to retrieve from their search, by typing in the maximum number of plates they wish to see. Time Display: Select whether results should be displayed in Heliocentric Julian Time or UT Time. Coordinate Display: Choose to display the coordinates in sexigesimal (degrees, minutes, and seconds) or decimal (degrees). File Format: Choose whether images should be delivered in JPEG or FITS format File Compression: Choose images to be delivered in TAR or ZIP files

Find a Plate

The database can be searched by plate classification attributes: Maximum results: Users may also narrow down the number of results they would like to retrieve from their search, by typing in the maximum number of plates they wish to see.

Magnitudes and Light Curves

Magnitudes and Light Curves

The existing light curve search tool is no longer maintained and may return errors when executing queries. Refreshing your browser may help with errors received due to timeouts.

We look forward to sharing new tools with you as we move forward with our technical overhaul of the DASCH technology stack. We intend to provide updates as soon as possible, but we cannot provide specific dates at this time. 

If you have questions please contact Daina Bouquin, Head Librarian of the Wolbach Library.