Description of the Hendrix IUE asteroid reflectance spectra bundle V2.0
=======================================================================

Bundle Generation Date: 2023-02-08
Peer Review: 2020_Asteroid_Review
Discipline node: Small Bodies Node


Content description for the Hendrix IUE asteroid reflectance spectra
bundle
===========================================================================

These
IUE data are part of the Repository for UV Spectral Data of Small
Bodies
(https://sbn.psi.edu/pds/resource/uvspec.html).

Observations:
The
raw IUE
data used in this study were obtained from the INES (IUE Newly
Extracted
Spectra) Web site. Spectra were taken with the Long Wavelength Prime
(LWP) and
the Long Wavelength Redundant (LWR) spectrographs, which cover the
185-335 nm
wavelength range with a spectral spacing of 0.27 nm. The NEWSIPS
versions of
these spectra were published by Roettger & Buratti (1994). The INES
files
benefit from an improved geometric correction, a more accurate
photometric
correction, and an increased signal-to-noise ratio of the extracted
IUE data
through the use of new processing algorithms (Wamsteker &
Gonzalez-Riestra
1998). Geometric information for all observations is given in
the Observational
Parameters file. 

Data Processing:
To determine the
reflectance measured in
the IUE observations, we used the equations outlined by
Hendrix and Vilas
(2006). We converted the spectra to photons cm-2 s-1
Angstrom-1 for division by
the solar spectrum. For all observations we used a
solar spectrum from SORCE
SOLSTICE/SIM (McClintock et al. 2000). The
observations were corrected for
satellite-Sun and satellite-Earth distances at
the time of each measurement.


Files and Filenames:
The data directory
includes individual reflectance
spectra for each observation (where each file
is named for the 5-digit exposure
number). For such targets where multiple
observations at similar phase angles
exist, the data directory includes average
reflectance spectra and the document
directory includes files
(objectname_avg_list.pdf) documenting which 
spectra
were averaged. The
document directory also includes thumbnail plots
(object
name_thumbnail_plot.pdf) of reflectance spectra, and the original IUE
header
files (object name_exposure number_ines_fits_headers.pdf).


Modification
History:
V1.0 included IUE data for 5 asteroids; V2.0 added
IUE data for an
additional 39 targets.

References:
Hendrix, A. R. and F.
Vilas 2006. The
Effects of Space Weathering at UV Wavelengths: S-class
Asteroids, Astron. J.:
132: 1396-1404.
McClintock, W. E., G. J. Rottman, and
T. N. Woods (2000), Solar
Stellar Irradiance Comparison Experiment II (SOLSTICE
II) for the NASA
Earth
Observing System's Solar Radiation and Climate
Experiment (SORCE)
Mission, Proc. SPIE, Earth Observ. Syst. V, 4135,
225–234.
Roettger, E. E., &
Buratti, B. J. 1994, Icarus, 112, 496
Wamsteker &
Gonzalez-Riestra 1998. in
Ultraviolet Astrophysics beyond the IUE Final
Archive, ed. W. Wamsteker & R.
Gonzalez Riestra ( ESA SP-413; Noordwijk: ESA)


Caveats to the data user
========================

For all targets, the IUE
data appear to be quite noisy shortward of about
2400-2500 Angstroms.