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Combined Analysis of Archival Photo Plate and CCD Data

Astronomical data from photo plates cover a time span of more than 100 years. Since modern CCD data are available for 25 years at most, the photo plate data are predestined for studying the long-term behavior or transient phenomena of stars. Especially young stars are candidates for such investigations.

The young star J1407 may serve as an example:

Photometry of the data of J1407 from four CCD sources (lower part) as well as three photographic plate archives (upper part).
R. Mentel
Photometry of the data of J1407 from four CCD sources (lower part) as well as three photographic plate archives (upper part).

Photometry of the data of J1407 from four CCD sources (lower part) as well as three photographic plate archives (upper part).

  • CCD data reveal a series of complex eclipses, interpreted as the transit of a huge debris ring system around a companion.
  • Photo plate data from 1895 to 1995 do not show any change in brightness.

Thus the possible period of the companion’s orbit could be constrained to the range of 14 to 18 years, helping to further constrain the mass of the companion.

For more details see: R. Mentel et al., A&A 619, A157 (2019)