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GREAT SOLAR
HELIUM ERUPTION

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This photograph of the sun
was taken using the extreme
ultraviolet radiation from ionized
helium, 304 Angstom wavelength.
It was taken on December 19, 1973
using the Solar Physics Branch's
SO82A Spectroheliograph
onboard the Skylab ATM.

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The Solar Physics Branch is part of the Naval Research Laboratory (NRL) Space Science Divison.

Researchers in the Solar Physics Branch have been involved in observational and theoretical studies of the solar atmosphere since the early years of the space age. Experiments developed at NRL have flown on NASA missions such as Skylab/ATM (see the picture above), the OSO satellite series, the Space Shuttle STS-3, Spacelab-2 and ATLAS missions.

Active Experimental Programs:

• The Solar Orbiter Heliosphic Imager is an remote sensing imaging instrument aboard the ESA Solar Orbiter. Solar Orbiter will be launched in 2017.
• The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) is a suite of solar and heliospheric imagers prepared by a consortium of institutions with Dr. Russell A. Howard as the PI. It was launched in October 2006. NASA STEREO mission is the third mission in NASA's Solar Terrestrial Probes line of advanced scientific missions in the Sun Earth Connections theme. STEREO is the first mission dedicated to understanding the physics associated with the initiation and propagation of Coronal Mass Ejections (CMEs). SECCHI is being built by institutions from the US, UK, Belgium, France, and Germany.

• The EUV Imaging Spectrometer (EIS) is being prepared by a consortium of institutions led by Prof J.L. Culhane at the MSSL/UCL in the UK. It will be launched on Japan's next solar physics mission, Solar-B, currently scheduled for launch in August 2004.

• The Large Angle Coronagraph-Spectrograph (LASCO) and Extreme ultraviolet Imaging Telescope (EIT) experiments are two instrument packages aboard the Solar and Heliospheric Observatory (SOHO). SOHO, a joint ESA/NASA mission, was launched on December 2, 1995. LASCO produces visible light coronal images from its three coronagraphs (C1, C2, and C3) extending from 1.1 to 32 solar radii. EIT produces ultraviolet images at various temperatures the solar atmosphere from the chromosphere to the corona.

• The Very high Angular resolution ULtraviolet Telescope (VAULT) is a new spectroscpic imaging instrument to replace HRTS. It collected extremely high resolution images (0.2 arc sec) of the Sun at Lyman-alpha (1216 A) during its first flight in May 1999 on a suborbital rocket.

Earlier Experimental Programs:

• The Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) experiment aboard the Upper Atmosphere Research Satellite (UARS) measured the the solar UV spectral irradiance in the 115-410 nm wavelength range from October 11, 1991 to August 1, 2005.

• The SUSIM ATLAS instrument flew on five times aboard the SpaceLab platform aboard the Space Shuttle. The latter three of these missions were part of the ATLAS program. The experiment measured the UV solar spectral irradiance from Ly-a to 400 nm.

• The High Resolution Telescope and Spectrograph (HRTS) experiment has collected spectroscopic observations of the Sun while flying on suborbital rockets since its first flight in 1975.

• The Solwind Coronagraph on the P78-1 satellite operated from March 29, 1979 through September 13, 1985.

New Mission Concept:

• The Advanced Spectrographic and Coronagraphic Explorer (ASCE) is a concept for an advanced coronal observatory which was selected for a Phase A study by NASA as a Medium Explorer or MIDEX mission. The PI of ASCE is John Kohl at the Smithsonian Astrophysical Observatory.

Solar and Astrophysical Database Projects:

• The Space Physics Data System's HRTS/SKYLAB database with solar data from the Solar Physics Branch's spectrograph and spectroheliograph instruments flown as part of the HRTS , Spacelab 2 and SKYLAB missions. This database is the under sponsorship of NASA's Space Physics Data System.

• The CHIANTI database for the calculation of astrophysical spectra. This database contains the most recent atomic data for calculating a collisionally dominated spectrum and is maintained by an international consortium of scientists.

Other Items of Interest:

• The EIT calibration rocket rocket flew successfully on October 16, 1997. Recovered Instrument and EUV images are doing fine.

• HRTS-10 was successfully flown on September 30, 1997.

• SOHO Mission status.

You can also visit the NRL Space Science Division home page.

Naval Research Laboratory (NRL)
4555 Overlook Avenue, SW
Washington, DC 20375
Solar Physics Branch / Code 7680

For more information, please send an email to the Solar Physics Branch  Webmaster