SOHOLASCO

SOHOLASCO refers to the LASCO instrument package on the Solar and Heliospheric Observatory (SOHO). SOHO is a joint ESA-NASA space observatory launched in 1995 and positioned at the first Lagrange point (L1) between the Sun and Earth, providing continuous observations of the Sun and the inner heliosphere. LASCO, the Large Angle and Spectrometric Coronagraph, is designed to image the solar corona by blocking direct sunlight with occulting disks, enabling measurements of coronal structure and solar eruptive events.

LASCO comprises two operating coronagraphs, C2 and C3. C2 observes the inner corona from about 2 to 6 solar radii, while C3 covers the outer corona from roughly 3.7 to 32 solar radii. A third design concept, C1, was developed but did not become a flight instrument on SOHO. The suite has produced a long history of observations used to study coronal mass ejections, solar wind, and solar activity.

LASCO has also been a prolific source of comet discoveries, particularly of sungrazing comets from the Kreutz family, contributing significantly to our knowledge of small bodies in the inner solar system. Data from LASCO are publicly available and widely used by the solar physics community for research and space-weather forecasting. The instrument continues to operate as part of the SOHO mission, contributing to long-term monitoring of the solar corona.