BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//ZContent.net//ZapCalLib 1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTART;TZID=Atlantic/Canary:20220405T123000
DTEND;TZID=Atlantic/Canary:20220405T133000
UID:iactalks-1559
X-WR-CALNAME: IAC Talks: Open Astronomy Seminars
X-ORIGINAL-URL: /iactalks/Talks/view/1559
CREATED:2022-04-05T12:30:00+01:00
X-WR-CALDESC: IAC Talks upcomming talks
SUMMARY:Magnetic Flux, Heating, & Flaring:  Clues from the Sun for Other St
 ars & Systems
DESCRIPTION:Magnetic Flux, Heating, & Flaring:  Clues from the Sun for Othe
 r Stars & Systems\nProf. Brian Welsch\n\nOn the Sun, the presence of magne
 tic flux at the photosphere is closely linked to (1) steady heating of the
  overlying atmosphere and (2) transient brightenings, the largest of which
  are flares.   I will discuss statistical properties of both phenomen
 a, with an emphasis on aspects of each that might apply to other astrophys
 ical objects, such as other stars or stellar remnants, and perhaps AGNs.&n
 bsp; Regarding heating, power-law scalings have been found to relate magne
 tic flux with steady coronal emission in both soft X-ray (SXR) and EUV ran
 ges.  A key observation is that the details of magnetic structure (fi
 eld strengths and their spatial gradients, including measured electric cur
 rents) appear not to affect heating rates. Similar SXR scalings have been 
 reported for G,K, and M dwarfs and classical T-Tauri stars.  Departur
 es from such scalings, whether on the Sun, other stars, or other objects, 
 might reveal important aspects of the heating mechanisms that drive steady
  emission, and should be sought.   Regarding flaring, again a power-l
 aw scaling between magnetic flux and flare SXR emission has been found, bu
 t with a different exponent.  Differences in these scalings suggest t
 hat steady heating fundamentally differs from flare heating, disfavoring t
 he “nanoflare” hypothesis (i.e., that steady coronal heating a
 rises from many weak, unresolved flares that are essentially scaled-down v
 ersions of larger flares).  Analogous differences in the scalings of 
 steady vs. flaring luminosities with magnetic flux on other objects could 
 constrain processes driving each type of emission.  Another key prope
 rty of flares is that they extract energy from the magnetic field, which i
 n the solar case leads to measurable changes in field strengths after flar
 es – photospheric field strengths tend to increase, coronal fields t
 end to decrease.  It is possible that analogous changes could be obse
 rved on other stars or objects (via, e.g., Zeeman or synchrotron  met
 hods). \n
END:VEVENT
END:VCALENDAR