The first working version of a “one-stop shopping” service for solar data
is now on line, giving scientists a much easier way to search for data on
specific solar phenomena and even to confirm the results of earlier

“The Virtual Solar Observatory or VSO makes it possible to access data
from multiple sources, even ones you didn’t know existed, at one fell
swoop” said Dr. Joseph B. Gurman of NASA’s Goddard Space Flight Center in
Greenbelt, MD.

The VSO will be discussed in two different papers to be presented at the
Fall 2004 meeting of the American Geophysical Union in San Francisco on
Tuesday morning, Dec. 14.

Gurman is the project manager for the VSO. Dr. Frank Hill of the National
Solar Observatory in Tucson, AZ, is the principal investigator. The
Association of Universities for Research in Astronomy operates the
National Solar Observatory under a cooperative agreement with the National
Science Foundation. Other members of the VSO team are at Stanford
University, Montana State University, and Southwest Research Institute.

“We have folks lining up to provide their data through VSO,” Gurman
continued. At the VSO’s core are decades of data and images from the
National Solar Observatory Digital Library (ground-based solar telescopes)
and NASA’s Solar Data Archive Center (spacecraft observations), which is
being transformed into the VSO. Other data services accessible in this
initial release are: Stanford University Helioseismology Archive, Owens
Valley Radio Observatory, Observatoire de Paris-Meudon, Montana State
University, and the High Altitude Observatory. Most of the data are
synoptic, covering the entire solar disk over long periods of time, but
the collection may grow to include more high-resolution observations that
focus on small parts of the Sun.

Like the nighttime National Virtual Observatory, the VSO does not hold all
solar data, but works from metadata, that is, information about
information held at the various archive sites. The VSO automatically sends
a user’s query to databases held at many sites, all over the Internet.
Those sites search in parallel, and the VSO packages and delivers their
answers to the user who can then refine the search or use links to access
the data directly from the data providers.

“The VSO puts together fifty different archives of solar data and allows
solar physicists to access it from a single database without having to
learn all fifty databases,” Hill explained.

Gurman credited Hill as “the driving force” behind the VSO effort. The
idea emerged after Hill had surveyed papers in the journal Solar Physics
and determined that a third of the papers worked from three or more
on-line data sources. Hill realized that improving access to the data
“could enable new kinds of science,” Gurman continued. Building on a prior
concept known as the “Whole Solar Catalog,” Hill started the VSO with a
“birds of a feather” working group meeting at the American Astronomical
Society’s Solar Physics Division meeting at Lake Tahoe, NV, in 2000.
Gurman also credited NSO’s Igor Suárez-Solá for developing the user
interface and parts of the search engine. Other major contributions were
made by Karen Tian at Stanford, Joe Hourclé at Goddard, and Alisdair Davey
at Southwest Research Institute in Boulder, Colorado (formerly with
Montana State University). Scientific input has come from Drs. Piet
Martens of Montana State University and Richard Bogart of Stanford

The VSO has several search options including time, instruments, and
spectral range. A scientist could ask the VSO to provide all the data that
were collected during the large flare events of Oct. 29, 2003, or specify
just the vector magnetograms (showing magnetic field strength and
direction) from NSO’s SOLIS instruments and the radio data from the Owens
Valley radio telescopes. The VSO will return links to the data and will
store the list, like an on-line store’s shopping cart, for future
reference. Gurman and Hill hope that scientists publishing papers based on
VSO searches will include links to their data shopping carts so other
scientists can call up the same data and reanalyze to confirm or challenge
the findings, or push the findings into new areas.

“This will let the scientists do more science and less data culling,”
Gurman said.

The VSO is open to anyone, he continued, and anyone can make data sources
available. “It can be as simple as a file server or a database manager
that responds to queries,” he added. No valuations or rankings will be
placed on the data. “It’s a marketplace where people will rapidly
determine which data are good.”


Fall 2004 AGU papers dealing with current and planned use of the VSO are:
STEREO in the Virtual Solar Observatory Context, J.A. Hourclé, et al

Solving Science Use Cases that Relate to the Sun and Heliosphere with
EGSO, R.D. Bentley, et al (SH21B-0415)
Doing Science with the VSO: Signatures of CME Initiation, A.R. Davey et al

Both Gurman and Hill will be at the AGU conference.

Joseph B. Gurman, Facility Scientist, Solar Data Analysis Center, NASA
Goddard Space Flight Center, Greenbelt, MD (; 301
286-4767) or
Frank Hill, National Solar Observatory, Tucson AZ (,