Rome Precision Solar Photometric Telescope: precision solar full-disk photometry during solar cycles 23-25

TL;DR

The Rome/PSPT telescope has provided a 27-year database of high-precision full-disk solar images across multiple wavelengths, enabling studies of solar irradiance variations, disk features, and linking historical and modern observations during solar cycles 23-25.

Contribution

This paper presents the longest continuous high-resolution full-disk solar photometry dataset from Rome/PSPT, covering solar cycles 23-25, and highlights its applications in solar physics research.

Findings

Long-term solar irradiance variation analysis

Insights into solar disk feature properties

Connection between historical and modern solar observations

Abstract

The Rome Precision Solar Photometric Telescope (Rome/PSPT) is a ground-based telescope engaged in precision solar photometry. It has a 27-year database of full-disk images of the photosphere and chromosphere beginning in 1996 and continuing to 2022. The solar images have been obtained daily, weather permitting, with approximately 2 arcsec/pixel scale in Ca II K line at 393.3 nm, G-band at 430.6 nm, and continuum in the blue and red parts of the spectrum at 409.4 nm and 607.2 nm, respectively. Regular observations were also performed at the green continuum at 535.7 nm for a period of about 18 months. Since the first-light, Rome/PSPT operations have been directed at understanding the source of short-and long-term solar irradiance changes, spanning from one minute to several months, and from one year to a few solar cycles, respectively. However, Rome/PSPT data have also served to study a variety of other topics, including the photometric properties of solar disk features and of the supergranulation manifested by the chromospheric network. Moreover, they have been unique in allowing to connect series of historical and modern full-disk solar observations, especially the Ca II K line data. Here, we provide an overview of the Rome/PSPT telescope and of the solar monitoring carried out with it from its first light to the present, across solar cycles 23-25. We also briefly describe the main results achieved with Rome/PSPT data, and give an overview of new results being derived with the whole time series of observations covering the period 1996-2022.