139 citations · 986 across the 53 of their papers we have counts for
6 papers · 1 filter
Astro2020 State of the Profession White Paper: Astronomy's Archival Materials
James Lattis, Wayne Osborn, Jennifer Lynn Bartlett +7
We argue that it is essential that the Astro2020 survey of the present state of American astronomy and the recommendations for the next decade address the issue of ensuring preserv…
The effect of telescope aperture, scattered light, and human vision on early measurements of sunspot and group numbers
Nina V. Karachik, Alexei A. Pevtsov, Yury A. Nagovitsyn
Early telescopic observations of sunspots were conducted with instruments of relatively small aperture. These instruments also suffered from a higher level of scattered light, and…
Evolution of Magnetic Helicity in Solar Cycle 24
Valery V. Pipin, Alexei A. Pevtsov, Yang Liu +1
We propose a novel approach to reconstruct the surface magnetic helicity density on the Sun or sun-like stars. The magnetic vector potential is determined via decomposition of vect…
Structure and evolution of the photospheric magnetic field in 2010 - 2017: comparison of SOLIS/VSM vector field and potential field
Ilpo I. Virtanen, Alexei A. Pevtsov, Kalevi Mursula
The line-of-sight (LOS) component of the large-scale photospheric magnetic field has been observed since the 1950s, but the daily full-disk observations of the full vector magnetic…
Reconstructing Extreme Space Weather from Planet Hosting Stars
V. S. Airapetian, V. Adibekyan, M. Ansdell +80
The field of exoplanetary science is making rapid progress both in statistical studies of exoplanet properties as well as in individual characterization. As space missions provide…
Historical astronomical data: urgent need for preservation, digitization enabling scientific exploration
Alexei Pevtsov, Elizabeth Griffin, Jonathan Grindlay +16
Over the past decades and even centuries, the astronomical community has accumulated a signif-icant heritage of recorded observations of a great many astronomical objects. Those re…