The Solar Genome
|Click on the images for larger version.|
Top: A close-up of a tiny part of the spectral atlas released
from the SUMER instrument, compared with the irradiance spectrum of Alpha Cen
A from HST-STIS.
Caption: With the release of a new "spectral atlas" from the SUMER instrument on board SOHO, the world's astronomers have a much more complete roadmap of what could be described as the "Solar genome". Also likened with its "fingerprint", a star's full spectrum uniquely pins down all its defining characteristics: Mass, elemental composition, age, and rotational speed.
The ultraviolet region of the spectrum is nearly all blocked by Earth's atmosphere, and so can only be thoroughly studied from spaceborne observatories. The SUMER spectral atlas is the best-ever analysis of the ultraviolet light from the Sun, spanning wavelengths from 670 to 1609 Ångstrøm (67 to 160.9 nanometers), and identifies some 1100 distinct emission lines, of which more than 150 had not been recorded or identified before SOHO.
The new atlas is being presented on 31 July 2001 by Dr. Werner Curdt of Max-Planck-Institut für Aeronomie in Lindau, Germany, at a workshop in Boulder, Colorado, on "The Future of Cool-Star Astrophysics". The atlas will also be published in a paper, "The SUMER Spectral Atlas of Solar-Disk Features" by W. Curdt et al., to appear in in Astronomy & Astrophysics, Vol. 375, No. 2, 4 August 2001.
Solar Ultraviolet Measurements of Emitted Radiation (SUMER);
Hubble Space Telescope Imaging Spectrograph (STIS)
|Taken:||21 June 2001|
|Picture credits:||SOHO/SUMER (ESA & NASA), HST-STIS (NASA & ESA), W. Curdt.|