000006791 001__ 6791
000006791 005__ 20240208150028.0
000006791 0247_ $$2DOI$$a 10.3847/2041-8213/acd853
000006791 037__ $$aSCART-2024-0081
000006791 100__ $$aHayakawa, Hisashi
000006791 245__ $$aMagnitude Estimates for the Carrington Flare in 1859 September: As Seen from the Original Records
000006791 260__ $$c2023
000006791 520__ $$aThe Carrington flare in 1859 September is a benchmark, as the earliest reported solar flare and as an event with one of the greatest terrestrial impacts. To date, no rigorous estimate of the energy of this flare has been made on the basis of the only direct observation available, its white-light emission. Here, we exploit the historical observations to obtain a magnitude estimate and express it in terms of its GOES soft X-ray class. From Carrington's original drawings, we estimated the area of the white-light flaring region to be 116 ± 25 msh. Carrington's account allows us to estimate the flare blackbody brightness temperature as ≈8800–10,900 K, given the most plausible interpretation of the reported flare brightness. This leads to an unprecedented class estimate of ≈X80 (X46–X126), on the modern revised GOES scale (a factor 1.43 higher than the traditional one). This substantially exceeds earlier estimates but is based on an explicit interpretation of Carrington's description. We also describe an alternative but less plausible estimation of the flare brightness, as adopted previously, to obtain a class estimate of ≈X14 (X9–X19). This now-deprecated scenario gives an estimate similar to that of with those of directly observed modern great flares. Approximations with "equivalent area," based on the Hinode observations, lead to comparable magnitudes and approve our estimates, though with a larger uncertainty range. We note that our preferred estimate is higher than the currently used value of X64.4 ± 7.2 (revised) based on indirect geomagnetic measurements.
000006791 594__ $$aSTCE
000006791 700__ $$aBechet, Sabrina
000006791 700__ $$aClette, Frédéric
000006791 700__ $$aHudson, Hugh S.
000006791 700__ $$aMaehara, Hiroyuki
000006791 700__ $$aNamekata, Kosuke
000006791 700__ $$aNotsu, Yuta
000006791 773__ $$n1$$pThe Astrophysical Journal $$v954$$y2023
000006791 8560_ $$fsabrina.bechet@ksb-orb.be
000006791 85642 $$ahttps://iopscience.iop.org/article/10.3847/2041-8213/acd853
000006791 905__ $$apublished in
000006791 980__ $$aREFERD