DASCH Project Instructions

Thank you for being a digital volunteer! It’s very important that this work is performed in a standardized manner, so please make the effort to read and follow these instructions.


How the Process Works




How the process works



We seek to balance quality and speed with our transcription process - which of course is still evolving as we continue to develop this service. At the moment, this is how our system works:

1) Anyone can start transcribing or add to a transcription of a document.

2) Once a volunteer decides they’ve “finished” and they’re ready for review, a different volunteer (who must have an account on the site) can review the transcription and either send it back for edits, or complete the transcription.

3) The finished transcript is sent to the Smithsonian, where it may be used immediately, or undergo additional work.

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The Digital Access to a Sky Century @ Harvard (DASCH) Project at Harvard-Smithsonian Astrophysical Observatory


Harvard College Observatory Plate Stacks houses roughly 500,000 glass negatives. The metadata for each photograph were recorded at the telescope in a logbook. Thus, the logs are the original descriptive materials for the photographic plates. We have a total of 1,570 logbooks in bound and loose-leaf format. Each image is a photograph of two logbook pages. We are transcribing the data from 13 columns of the page. Please read the instructions below for details of how to transcribe each column.


Navigating the DASCH page


To navigate the DASCH page, please transcribe columns from left to right, labeled according to the column title. Adjust the size of the image window to help you focus on each row as you transcribe. Be sure to type in or select all the information you can for the fields in each section before you check the box at the bottom that reads “Complete and Mark for Review.”

NOTE: You will not transcribe data from the following columns:

  • Tel. E. or W.
  • Load
  • Focus
  • Prisms
  • Cl'ds
  • Cl'k
  • Dew
  • Ref.
  • Obs'r

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      Column Instructions


      This project is transcribing thirteen columns, row by row (or line by line). When you enter data in the bottom-most row, a new row will be generated.

      Column 1

      The number at the top left is the page number to transcribe. All numbers will be even. Do not enter the page number at the top of the right page.

      Column 2: “Plate”

      The “Plate” column defines the number for each plate. All numbers proceed in chronological order. Carefully enter the number, while checking the preceding row to ensure the numbers are chronological.

      Column 3: “Class”

      The “Class” column defines the type of emulsion and exposure. Classes are L (blue sensitive), M (multiple exposure), Ec. Class letters may be followed by a superscript of 1 or 2. These should be transcribed as L1 and L2. These numbers mean L1 was yellow sensitive and L2 was red sensitive. Where a “ (ditto mark) appears, please copy the class from the record above.

      Column 4: “Object”

      Column 4 describes the object the telescope was imaging. Where a “ (ditto mark) appears, please copy the object from the record above.

      Column 5: “R.A.”

      Column 5 describes “R.A.” or Right Ascension. R.A. is measured in time using a 24-hour clock. Keystrokes are entirely numerical, with a space separating two or three times of R.A. (hour, minute, second). The first part is 1 or 2 digits spanning the numbers 0-23. The second part is always 2 digits, spanning the numbers 00-59. The third part is always 2 digits, spanning the numbers 00-59. If no seconds data is provided, please enter only hour and minute. In this example image, you would transcribe: 17 52

      Column 6: “Dec”

      Column 6 describes “Dec.” or Declination. Declination is measured in degrees, like Earth’s latitude. Declination spans +90 to -90. Keystrokes are entirely numeric, with a - to indicate South. Transcribe exactly what you see, specifically the number of decimal points.

      Column 7: “Start”

      Column 7 describes “Started” or the exposure start time. The start time operates in a 24-hour format. Keystrokes are numeric, with a space separating hours from minutes and minutes from seconds. Hours of time span 0-23 - Minutes of time span 0-59 - Seconds of time span 0-59. The format is HH MM SS so you would transcribe: 19 42 - in this example image, there are no seconds so it is left blank.

      Column 8: “Obs H.A.”

      Column 8 describes “Obs. H.A.” or the Observed Hour Angle. The Hour Angle appears similar to standard time and is normally followed by an “E” or “W” for East or West. Use a space to separate hours from minutes of time. A space also separates minutes from E or W, e.g. 1 50 W as shown in the example image.

      Column 9: “Obs Dec”

      Column 9 describes “Obs. Dec.” or Observed Declination. Declination is measured in degrees, like Earth’s latitude. Declination spans +90 to -90. Keystrokes are entirely numeric, with a - to indicate South. Transcribe exactly what you see, specifically the number of decimal points. In the example image, you would transcribe: -36.4

      Column 10: “Stop”

      Column 10 describes “Stopped” or the exposure stop time. The stop time operates in a 24-hour format. Keystrokes are numeric, with a space separating hours from minutes and minutes from seconds. Hours of time span 0-23 - Minutes of time span 0-59 - Seconds of time span 0-59.

      Column 11: “Exp”

      Column 11 describes “Exp.” or the plate’s length of Exposure time in minutes. Keystrokes are entirely numeric and should be one, two or three digits.

      Column 12: “Date”

      Column 12 describes the date the plate was taken. In these logbooks, the date is written in its own line. The date pertains only to the plate information written beneath it. When a new handwritten date appears,the date has changed. The “day” is overnight and this spans two numbers, as in Jan 1-2. Omit non-numeric mention of days, as in “Tues-Weds.” Please use the format MMM DD-DD YYYY. Example: Mar 27-28 1933

      Column 13: “Miscellaneous”

      Column 13 describes miscellaneous remarks about the exposure. Please transcribe the content of the remarks column in full.

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      Additional Information on Page


      Outside of the specific areas we've asked you to capture in each section, please ignore and do not attempt to capture any additional information on the logbooks.


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