SUMMARY OF SEQUENCE NUMBER 200029

SUMMARY OF SEQUENCE NUMBER 200029

Title: ACIS/HETG SPECTROSCOPY OF THE ACTIVE BINARIES ALGOL & UX ARI

Observer: DRAKE

Subject Category: Normal Stars and WD

Seq: 200029 ObsId: 00604

Long-term Plan bin: 28-Mar-2000

ABSTRACT

Previous low- and moderate-resolution X-ray spectroscopy of active binary stars have yielded surprising results concerning the abundances of the elements in these coronal plasmas, viz., that, in almost every well-studied case, a solar photospheric abundance plasma model cannot fit the observed spectrum: e.g., in some stars, Fe abundances of 10% of the solar value have been inferred. To verify and extend these findings, we propose to observe with the HETG two of the best-studied such stars, Algol and UX Ari. We will study the detailed structure of the He-like multiplets of the abundant elements O, Ne, Mg, Si, S, Ar, Ca, and Fe, and rederive their abundances, and also search for anomalous line ratios due to effects such as high resonance-line opacity and/or high electron densities.

TARGET SUMMARY

TARGET NAME RADEC TIME SI GRAT TYPE TC ROLL PRE PHASE MULTI PRI
ALGOL
47.042083
40.955667
50.00000
ACIS-S
HETG
GO
yes
no
no
no
no
5

IMAGES

(NOTE: RASS images currently only available for targets LTS scheduled on or after Apr-09-2000)

Roll/Visibility

PARAMETERS

Obscat Parameters