Astronomical photographic data archives: Recent status

Abstract

I briefly present and discuss the recent status (with emphasis on digitization and data access) of astronomical photographic data archives worldwide, both photometric and spectroscopic, including various digitization techniques, automated data evaluation pipelines, astrophysical use, and public access. Although there are two major astronomical plate digitization projects (Harvard DASCH USA and APPLAUSE representing German Bamberg, Potsdam and Hamburg plate collections), the majority of astronomical photographic data archives are still awaiting digitization. Numerous plate archives have been visited, and in many of them, the glass plates are affected by various degradation types such as gold decease, sometimes progressing so fast that digitization is of great importance, taking into account the enormous scientific value of these databases.

Long term follow-up coverage of Gaia photometric alert sources by Ondrejov robotic telescopes

“…We note that in addition to follow-up and monitoring by recent robotic telescopes, additional photometric data can be obtained from astronomical data archives namely large collections of astronomical photographic plates. These databases can add photometry for these sources typically for epochs between 1890 and 1980 including faint sources down to magnitude 20 (Hudec, 2019) (Hudec, 2018). This approach can extend the photometric coverage for selected Gaia alert sources for several decades or even more.…”

“…The robotic telescopes (RT) at the Ondrejov Observatory (recently 3 RTs: CTA-N/FRAM (recently at La Palma), D50, BART/SBT), apart from gamma-ray bursts (GRB) follow-up, provide valuable data for analyses of various types of high-energy (HE) sources (Nekola et al, 2009(Nekola et al, , 2010Hudec, 2019;Štrobl et al, 2019). Up to 100 targets are in the list for continuous monitoring, mostly IN-TEGRAL HE sources, blazars, cataclysmic variables (CVs), and newly detected Gaia alert sources.…”

Proposal of optical sky monitoring with subsecond cadence

“…Photographic plates of different monitoring programs are stored at several places in the world. A comprehensive overview about plate archives is given by Hudec (2019).…”

Comparison of Gaia BP/RP spectra with LDS (Low Dispersion Spectroscopy) photographic sky surveys

“…There is also the possibility of spectroscopic Gaia alerts and Follow-up by ground-based RTs with LDS. As already mentioned, the plate sky surveys can add long-term coverage and historical epochs to these analyses Hudec & Hudec (2013) Hudec (2019.…”