The Hydrogen-Alpha Rapid Dynamics camera (HARDcam) is a high cadence imager installed as a common-user instrument on the Dunn Solar Telescope at the National Solar Observatory in New Mexico since 2012. It was designed, built and maintained by Queen’s University Belfast. It is capable of imaging the lower solar atmosphere at frame rates up to 70 frames-per-second and a diffraction-limited spatial sampling of 0.069 arcsecs/pixel.
This image shows a sunspot in active region AR 12146 as observed on the 24th of August 2014 with HARDcam in the chromospheric H-alpha line (656.3 nm). Sunspots are transient regions with large magnetic fields. The magnetic fields suppress convection within the spot and so the spot is cooler than its surroundings, therefore, appearing dark. Phenomena such as magnetic field oscillations and solar flares are often studied in the vicinity of sunspots. This image was enhanced after acquisition using the Multi-scale Gaussian Normalization (MGN) approach.
Image credit: Peter H. Keys, David B. Jess (QUB)
Sunspot observed in Ca II K spectral line
The same sunspot in three different layers
A sunspot observed in multiple spectral lines
The amazing chromosphere above an active region (1/3)
The amazing chromosphere above an active region (2/3)
The amazing chromosphere above an active region (3/3)