7702 20260105155514.0 10.3847/1538-4357/ae0d90 DOI SCART-2026-0010 Panesar, Navdeep K. Buildup, Explosion, and Untwisting of a Solar Active Region Jet Observed with Solar Orbiter, IRIS, and SDO 2025 We present detailed analysis of an active region coronal jet accompanying a minifilament eruption that is fully captured and well resolved in high spatial resolution 174 Å coronal images from Solar Orbiter’s Extreme Ultraviolet Imager (EUI). The active region jet is simultaneously observed by the Interface Region Imaging Spectrograph and the Solar Dynamics Observatory. An erupting minifilament is rooted at the edge of an active region where mixed-polarity magnetic flux is present. Minority-polarity positive flux merges and cancels with the active region’s dominant negative flux at an average rate of 1019 Mx hr−1, building a minifilament-holding flux rope and triggering its eruption. The eruption shows a slow rise followed by a fast rise, akin to large-scale filament eruptions. EUI images and Mg II k spectra, displaying simultaneously blueshift and redshift at the opposite edges of the spire, indicate counterclockwise untwisting of the jet spire. This jet is the clearest, most comprehensively observed active-region jet with this instrument set, displaying striking similarities with quiet Sun and coronal hole jets. Its magnetic (≤1028 erg), thermal (1025 erg), and kinetic (1025 erg) energies suggest a significant contribution to local coronal heating. We conclude that magnetic flux cancelation builds a minifilament-carrying twisted flux rope and also eventually triggers the flux rope’s eruption that makes the coronal jet, in line with our recent results on the buildup and explosion of solar coronal jets in quiet Sun and coronal holes. That is, this active region jet clearly works the same way as the vast majority of quiet Sun and coronal hole jets. STCE Solar Orbiter EUI jet Sterling, Alphonse C. Moore, Ronald L. Tiwari, Sanjiv K. Berghmans, David Zhukov, Andrei Mierla, Marilena Verbeeck, Cis Stegen, Koen The Astrophysical Journal Letters, 994 2025 2, id.164 david.berghmans@ksb-orb.be https://arxiv.org/abs/2510.05439 https://iopscience.iop.org/article/10.3847/1538-4357/ae0d90 published in REFERD