The following document lists the file abstract/DBEINTEM_PNEBULAE.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
SCIENTIFIC ABSTRACT
The objectives of this proposal are the following:
1. Investigate the abundances of iron, magnesium, silicon in planetary
nebulae. For iron, very little is known. For the other elements IUE
spectra are available, but only for some nearby nebulae. These elements
have useful lines in the SWS spectral range. We propose to measure these
abundances in a variety of nebulae.
2. Carbon abundances, as deduced from IUE observations, are not well
understood. To help resolve this question, we propose to try to observe
the CII line at 157 microns in a number of galactic-bulge nebulae, for
which we have reliable distance estimates. The NII line at 120 microns,
which will also be measured, will help in the interpretation, allowing to
distinguish between the central star and circumstellar material.
3. H2, OI and CII lines will be measured in a number of nebulae to try to
assess the amount of neutral material surrounding some nebulae. The OI
and CII lines are in the LWS range.
4. For two bright high-excitation nebulae full-resolution full SWS scans
will be made and a number of lines will be studied in more detail. The
results will serve as bench marks for other studies in the SWS Central
Program.
5. One extended nebula will be investigated by observing a number of
lines in a raster, to explore the excitation variations through the
nebula.
OBSERVATION SUMMARY
Observation modes are detailed in the scientific justification.
summary of proposed observations:
obs. modes spring autumn
1 IC418 S11 S2H P 34 min
2 NGC 2346 S11 S2 P 30 min
3 NGC 2440 S14 P 112 min
S2F 35 min
4 NGC 3132 S11 S2 P 30 min
5 NGC 3242 S11 S2 P 30 min
6 NGC 3918 S11 S2 P 30 min 30 min
7 NGC 5315 S11 S2 P 30 min
8 He2-113 S11 S2H P 34 min
9 He 2-131 S11 S2 P 30 min
10 NGC 6153 S11 S2 P 30 min
11 NGC 6302 S14 P 112 min
S2F 35 min
12 NGC 6543 S11 S2 P 30 min 30 min
13 NGC 6537 S11 S2 P 30 min
14 NGC 6572 S11 S2 P 30 min
15 Vy 2-2 S11 S2H P 34 min
16 BD+30 3639 S11 S2H P 34 min
17 IC4997 S11 S2H P 34 min
18 NGC 7027 S14 P 112 min 112 min
S2F 35 min 35 min
19 IRAS21282+5050 S12 L 49 min 49 min
20 pk350+4.1 S12 L 49 min
21 pk355+3.2 S12 L 49 min
22 pk359-1.2 S12 L 49 min
23 pk359-2.3 S12 L 49 min
24 Cn 1-5 S12 L 49 min
25 NGC 246 S2R 12 min 12 min
26-36 NGC 246
(continued, raster) S2R 99 min 99 min
Total 638 min 1045 min
10.6 hrs 17.4 hrs