Eclipse Observations of the Extreme Solar Limb Profile of HI Pfund $\beta$ Emission.
Session 44 -- Solar Observations and Theory
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

## [44.12] Eclipse Observations of the Extreme Solar Limb Profile of HI Pfund $\beta$ Emission.

T.A.Clark ( U Calgary), C.A.Lindsey, D.M.Rabin, W.C.Livingston (NSO, Tucson)

A region of the infrared solar spectrum (2147.7 - 2150.1 $cm^{-1}$) around the HI Pfund $\beta$ line (2148.79 $cm^{-1}$) was monitored through 3 eclipse "contacts" with the Amber InSb array on the Main spectrograph on the McMath-Pierce telescope during the 10 May 1994 partial solar eclipse over Kitt Peak National Observatory to produce limb profiles of intensity and line width to an angular resolution of 0.15 arc second. This line is broad (FWHM = 0.9 $cm^{-1}$ and shallow (5.7\%) in absorption at disk center but shows a narrow emission core above the continuum envelope at 2 arc seconds inside the limb which remains visible out to 4.5 arc seconds beyond the continuum limb. The Pfund $\beta$ peak intensity appears to follow the continuum profile at the limb but then intensifies again to reach a peak at about 1000 km above the limb in a manner similar to that of the HeI D3 line. The line width becomes narrower with height above the limb, reaching a FWHM of 0.22 $cm^{-1}$ at several arc seconds above the limb. These profiles will be discussed in relation to those of other HI lines above the solar limb. This work was supported by NSERC of Canada and by NSO, Tucson.