NuSTAR Observation of Quiet Sun X-ray Bright Points

NuSTAR is a focusing hard X-ray telescope designed for observing astrophysical sources, but it is also capable of being pointed at the Sun. NuSTAR’s much greater sensitivity compared to RHESSI and the current minimum of the solar activity cycle provide a unique opportunity to investigate quiet Sun features that it has previously not been possible to with X-ray imaging spectroscopy. We present analysis from NuSTAR quiet Sun full disk mosaics from April 2019. With the absence of very bright sources, these mosaics show very small and faint X-ray bright points. We investigate the contribution of these small events to heating the solar atmosphere. The X-ray spectra of these features have been fit, allowing for estimates of their temperatures and emission measures to be obtained. The temperatures were found to lie in the range 1.2–3.5 MK. The temperatures and emission measures predicted by the spectral fits can be tested through comparison to SDO/AIA observations. Using the characteristics of the bright points found from their spectra, heating processes occurring in these features will be investigated.