Multi-instrument and Multispacecraft Observations of a Writhed Magnetic Flux Rope in a Halo Coronal Mass Ejection on 2022 January 29

We report on a writhed magnetic flux rope (MFR) eruption originating from active region 12936 located at N18E06, associated with a halo coronal mass ejection that erupted on 2022 January 29. To our knowledge, this event is among the first cases where a writhed MFR has been comprehensively observed from both solar and in situ perspectives. The Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) hot channels (94 and 131 Å) have detected a slow rise of the writhed MFR, where its western elbow (flux rope west, FRw) expands in the NW direction while the eastern elbow (flux rope east, FRe) expands in the NE direction. Using a two flux rope (FR) segment approximation, the graduated cylindrical shell (GCS) fit to EUV and white-light images yield a tilt of 29 ∘ for FRw (pointing towards the SE) and 60 ∘ for FRe (pointing towards the NE), indicating a writhing motion of the MFR axis. On 2022 February 2, the subsequent magnetic cloud (MC) was fortuitously intercepted by three closely spaced spacecraft: STEREO Ahead (STA, 34 . ° 6 east), Wind at the first Lagrange point, and Solar Orbiter (SolO, 18 . ° 6 east). The MC tilts obtained from Lundquist fitting agree with the GCS tilts within ∼1 ∘ for FRw and ∼9 ∘ for FRe. In addition, the GCS-fit propagation direction for FRw is N10E06, which is close to Wind, and for FRe is N09E26, which lies between STA and SolO. The GCS-fit locations are consistent with the in situ observations, where Wind detected FRw and STA and SolO intercepted FRe at opposite sides of the MC center.