Table information for 'dasch.plates'

General

Table Description: This table is a union of the narrow_plates and wide_plates tables. For non-historic use, you probably get better results looking at narrow_plates.

This table is available for ADQL queries and through the TAP endpoint.

Resource Description: This is a re-publication of the metadata from StarGlass, an information service operated by Harvard College Observatory (HCO) which primarily indexes the holdings of the HCO Astronomical Photographic Glass Plate Collection. This collection is the world's largest archive of astronomical photographic glass plates, consisting of more than 550,000 images documenting the entire sky over a century-long time baseline. Approximately 430,000 plates in the collection, representing the subset of sky images deemed suitable for astrometric and photometric calibration, have been digitized at high resolution by the DASCH project. StarGlass makes available both photographs and calibrated scientific data when available. This resource re-publishes the metadata in separate tables for “narrow” and “wide” (extremely wide-field) plates. The narrow plates are also published in an obscore table and as a SIAP2 service.

For a list of all services and tables belonging to this table's resource, see Information on resource 'DASCH in the VO'

Citing this table

This table has an associated publication. If you use data from it, it may be appropriate to reference 2012IAUS..285...29G (ADS BibTeX entry for the publication) either in addition to or instead of the service reference.

To cite the table as such, we suggest the following BibTeX entry:

@MISC{vo:dasch_plates,
  year=2024,
  title={{DASCH} in the VO},
  author={Harvard College Observatory},
  url={https://dc.zah.uni-heidelberg.de/tableinfo/dasch.plates},
  howpublished={{VO} resource provided by the {GAVO} Data Center}
}

Columns

Sorted by DB column index. [Sort alphabetically]

NameTable Head DescriptionUnitUCD
dataproduct_type Product type High level scientific classification of the data product, taken from an enumeration N/A meta.code.class
dataproduct_subtype Subtype Data product specific type N/A meta.code.class
calib_level Calibration level Amount of data processing that has been applied to the data [Note calib] N/A meta.code;obs.calib
obs_collection Collection Name of a data collection (e.g., project name) this data belongs to N/A meta.id
obs_id Obs. Id Unique identifier for an observation N/A meta.id
obs_title Title Free-from title of the data set N/A meta.title;obs
obs_publisher_did Pub. DID Dataset identifier assigned by the publisher. N/A meta.ref.ivoid
obs_creator_did Creator DID Dataset identifier assigned by the creator. N/A meta.id
access_url Access URL The URL at which to obtain the data set. N/A meta.ref.url
access_format Media Type MIME type of the resource at access_url N/A meta.code.mime
access_estsize Size Estimated size of data product kbyte phys.size;meta.file
target_name Target Name Object a targeted observation targeted N/A meta.id;src
target_class Target Class Class of the target object (star, QSO, ...) N/A src.class
s_ra RA RA of (center of) observation, ICRS deg pos.eq.ra
s_dec Dec Dec of (center of) observation, ICRS deg pos.eq.dec
s_fov FoV Approximate spatial extent for the region covered by the observation deg phys.angSize;instr.fov
s_region coverage Region covered by the observation, as a polygon N/A pos.outline;obs.field
s_resolution Space Res. Best spatial resolution within the data set arcsec pos.angResolution
t_min Min. t Lower bound of times represented in the data set d time.start;obs.exposure
t_max T_max Upper bound of times represented in the data set d time.end;obs.exposure
t_exptime Exp. Time Total exposure time s time.duration;obs.exposure
t_resolution Res. t Minimal significant time interval along the time axis s time.resolution
em_min λ_min Minimal wavelength represented within the data set m em.wl;stat.min
em_max λ_max Maximal wavelength represented within the data set m em.wl;stat.max
em_res_power λ/Δλ Spectral resolving power lambda/delta lambda N/A spect.resolution
o_ucd Obs. UCD UCD for the product's observable N/A meta.ucd
pol_states Pol. States List of polarization states in the data set N/A meta.code;phys.polarization
facility_name Facility Name of the facility at which data was taken N/A meta.id;instr.tel
instrument_name Instrument Name of the instrument that produced the data N/A meta.id;instr
s_xel1 |X| Number of elements (typically pixels) along the first spatial axis. N/A meta.number
s_xel2 |Y| Number of elements (typically pixels) along the second spatial axis. N/A meta.number
t_xel |t| Number of elements (typically pixels) along the time axis. N/A meta.number
em_xel |λ| Number of elements (typically pixels) along the spectral axis. N/A meta.number
pol_xel |Pol| Number of elements (typically pixels) along the polarization axis. N/A meta.number
s_pixel_scale Pix. Scale Sampling period in world coordinate units along the spatial axis arcsec phys.angSize;instr.pixel
em_ucd Spect. UCD Nature of the product's spectral axis (typically, em.freq, em.wl, or em.energy) N/A meta.ucd
source_table Source Table Name of a TAP-queriable table this data originates from. This source table usually provides more information on the the data than what is given in obscore. See the TAP_SCHEMA of the originating TAP server for details. N/A meta.id;meta.table
dasch_id DASCH id Plate identifier in DASCH N/A meta.id;meta.main
plate_comment Plate Comment Comment associated with plate describing context or content N/A meta.note
plate_class Class Plate class; Values are taken from https://library.cfa.harvard.edu/plate-classes N/A meta.code
mosaics Plates Metadata on the FITS files of the scans available; this is largely used by GAVO to produce the datalink document. In case you want to use it directly, see https://starglass.cfa.harvard.edu/docs/api/mosaics.html N/A meta;meta.dataset
datalinks URLs Links to various artefacts. We only use this to figure out the presence of certain artefacts here, since the links typically need an API key. Actual access via datalink goes through our getprod service that handles the API key juggling. N/A N/A

Columns that are parts of indices are marked like this.

Other

The following services may use the data contained in this table:

VOResource

VO nerds may sometimes need VOResource XML for this table.

Notes

Note calib

The calib_level flag takes the following values:

0 Raw Instrumental data requiring instrument-specific tools
1 Instrumental data processable with standard tools
2 Calibrated, science-ready data without instrument signature
3 Enhanced data products (e.g., mosaics)