Spectral Databases and Tools

Here we provide an assortment of stellar spectra of interest to planetary modelers, model-generated planetary spectra of Earth, and a collection of line lists and absorption cross-sections for molecules of relevance to planetary atmospheres and biosignatures:

Molecular Line Lists and Absorption Cross-Sections

Of critical importance to our spectrum simulators are spectroscopic line lists, which describe the wavelength and strength of gas absorption lines from the ultraviolet to the far-infrared, as well as how the line shapes depend on various input parameters (e.g. temperature and pressure). These data come from a variety of sources, including lab measurements and theoretical calculations. We maintain this database by collecting data from updated, existing line lists (e.g. HITRAN, GEISA), and compiling data from new, peer-reviewed studies.  We also provide a related tool to plot line list data for a user-selected molecule, database, and wavelength/wavenumber range.

VPL Molecular Spectroscopic Database

Molecular Spectral Search Engine

This tool allows the user to query the HITRAN data and view the spectra of molecules that have features within a given wave number/wavelength range. The user can then identify molecules that correspond to spectroscopic features in spectra obtained by spacecraft or telescopes.

VPL Molecular Spectral Search Engine

Stellar Spectra 

Our stellar spectra include two M-stars: AD Leo (M4.5V) and GJ 644 (M3.5Ve) (Segura, et al, 2005), and five others from publications by the VPL team spanning from far-ultraviolet to far-infrared (the Sun; the F2V HD128167; the G0V low-activity star HD114710; the G0V high-activity star HD206860; and the K2V star HD22049.) 

M Star Spectra:  Two spectra from Segura, et al, 2005: AD Leo (M4.5V) and GJ 644 (M3.5Ve). Images and Data. 

Other Stellar Spectra:  Five stellar spectra from publications by the VPL team spanning from far-ultraviolet to far-infrared (the Sun; the F2V HD128167; the G0V low-activity star HD114710; the G0V high-activity star HD206860; and the K2V star HD22049.) Images and Data.

Planetary Spectra 

Our planetary spectra include both spatially and temporally resolved synthetic spectra of Earth, validated with visible photometric and moderate resolution near-infrared observations from NASA’s EPOXI spacecraft. We have used our model to generate both 24-hour disk-averaged spectra for the dates of the EPOXI observations; as well as spectra taken over the course of an entire orbit. The model takes into account realistic scattering, absorption, and emission from the atmosphere, clouds, and surface, and is described in Robinson et al. (2011).
 
VPL Model Spectra for 3 EPOXI Observation Dates: Spectral Dataset 
 
VPL Model Spectra for Earth Through An Orbit: Spectral Dataset
 

Biological Pigment Spectra

A database of spectral absorbance or absorption coefficients of biological pigments, including but not limited to photosynthetic pigments and screening compounds for protection against radiation.

VPL Biological Pigments Database