Bibcode
Pottasch, S. R.; Mampaso, A.; Manchado, A.; Menzies, J.
Bibliographical reference
IN: Hydrogen deficient stars and related objects; Proceedings of the Eighty-seventh IAU Colloquium, Mysore, India, Nov. 10-15, 1985 (A87-37451 16-90). Dordrecht, D. Reidel Publishing Co., 1986, p. 359-364; Discussion, p. 365.
Advertised on:
0
1986
Citations
13
Refereed citations
11
Description
New spectra of A78 and A58 at different positions in the nebulae are
presented. An abundance gradient is found in A78, extending quite close
to the center. Similarly, the nebulous knot near the center of A58 has
considerably higher heavy element abundances than the outer regions of
this nebula. The ionization state is considerably lower in A58 than A78.
In A78 most of the neon is in the form of Ne(3+) and Ne(4+), indicating
that the standard ionization correction factor as used by Jacoby and
Ford (1983), is substantially in error. Finally, the very high infrared
excesses found in these nebulae are discussed.