Section of spectrum No. 11 showing the MgI-b triplet in emission in the 'reversing layer'

Descriptions of spectra

0. (Ha 1/60s) Chromospheric ring from S through NE with two spots to NW (Ha). Bright SE part seen in D₃, MgI, Hb, HeI 4471, Hg, Hd. Some faint bright lines seen longward of MgI. Bright southern prominence seen in all lines except MgI - which shows just a segment of the low chromosphere.
1. (Ha 1/30s) Lost the MgI lines. Ha appearance similar to 1. Can now see the [FeX] and [FeXIV] rings with bright patches in the E (just below centre) and NW. The elevated NW prominence is visible in D₃. Coronal continuum becoming more prominent.
2. (Ha 1/15s) All three NW prominences now visible in D₃ and the brightest (central) one also in Hb. Can just see MgI in emission on the southern limb. The [FeXIV] ring is complete. Fainter prominences to NE also visible in D₃.
3. (Ha 1/8s) Much structure in D₃ and several prominences visible in Hb. Can just discern CaII H and K. The [FeXIV] ring is very clear and the light on the bright E part fans upwards by about 0.15 R_sun. An extension is also seen around the elevated prominence in the W. MgI emission still faintly visible. The elevated prominence in the NW is about 0.08 R_sun high.
4. (Ha 1/4s) H and K clearly visible now. MgI still just visible in emission. Coronal lines bright E, W and NW. HeI 4471 visible in southern prominence.
5. (Ha 1/2s) HeI 4471 and CaII H and K clear. A high resolution (4.5MB jpeg) of this and spectrum 4 has been produced.
6. (Ha 1s) The CaII h-line appears double (H-epsilon ?) and also, possibly, does K.
7. (Ha ~10s) Rather burned out and trailed. 4471 clear.
8. (Ha 1/15s) Emission can be seen in Ha on the limb about 0.1 R_sun below the elevated prominence. The NW complex now shows six components in Ha. MgI is now visible in emission in the brightest NW prominence.
9. (Ha 1/15s) A string of blobs now shows in the W and SW in Ha - tracing the limb. The western limb is now brighter in the coronal lines. MgI brightening in the N.
10. (Ha 1/15s) (1/15s) Western limb brightening. MgI emission now very clear in the N. (see header picture)
11. (Ha 1/30s)
12. (Ha 1/60s) Bright western limb and some photospheric continuum. Many lines in emission, most prominently MgI, NaI-D (resolved). Emission line near 6500A, identified with BaII 6496.9. Can still see the coronal lines in the NW. A spectrum plot with a wavelength scale and a solar absorption spectrum for comparison shows the emission lines. The line doubling in the blue is due to defocus.
13. (Ha 1/60s) Strong photospheric continuum. Balmer lines, D₃, MgI and [FeXIV] still seen in emission in the west.

nb. The Sun is 3.4mm in diameter on the film.

A Fraunhofer spectrum taken with the same grating but at a focal length of only 180mm. This is on B&W negative film whose spectral response does not extend to Ha. It has been spatially averaged.