The Heliospheric Imager-1 (HI-1) telescope is part of the Sun Earth Connection Coronal and Heliospheric Investigations (SECCHI) instrument suite on the NASA STEREO mission. The SECCHI on the two STEREO spacecraft are identical suites of remote sensing instruments designed to observe coronal mass ejections (CMEs) at the Sun and in transit outwards to 1 AU. The HI-1 telescope observes the inner heliosphere from 12 to 84 solar radii with the band-pass wavelength of 450-750 nm.

The Heliospheric Imager-2 (HI-2) telescope is part of the Sun Earth Connection Coronal and Heliospheric Investigations (SECCHI) instrument suite on the NASA STEREO mission. The SECCHI on the two STEREO spacecraft are identical suites of remote sensing instruments designed to observe coronal mass ejections (CMEs) at the Sun and in transit outwards to 1 AU. The HI-2 telescope observes the inner heliosphere from 66 to 318 solar radii with the band-pass wavelength of 450-750 nm.

The Heliospheric Imager-2 (HI-2) telescope is part of the Sun Earth Connection Coronal and Heliospheric Investigations (SECCHI) instrument suite on the NASA STEREO mission. The SECCHI on the two STEREO spacecraft are identical suites of remote sensing instruments designed to observe coronal mass ejections (CMEs) at the Sun and in transit outwards to 1 AU. The HI-2 telescope observes the inner heliosphere from 66 to 318 solar radii with the band-pass wavelength of 450-750 nm.

The Extreme Ultraviolet Imager (EUVI) is part of the Sun Earth Connection Coronal and Heliospheric Investigations (SECCHI) instrument suite on the NASA STEREO mission. The SECCHI on the two STEREO spacecraft are identical suites of remote sensing instruments designed to observe coronal mass ejections (CMEs) at the Sun and in transit outwards to 1 AU.EUVI measured emission lines at 30.4 nm (He II), 17.1 nm (Fe IX), 19.5 nm (Fe XII), and 21.1 nm (Fe XIV). The EUVI's 2048 x 2048 pixel detectors have a field of view out to 1.7 solar radii, and observe in four spectral channels that span the 0.1 to 20 MK temperature range. In addition to its view from two vantage points, the EUVI will provide a substantial improvement in image resolution and image cadence over its predecessor SOHO-EIT, while complying with the more restricted mass, power, and volume allocations on the STEREO mission.

The Extreme Ultraviolet Imager (EUVI) is part of the Sun Earth Connection Coronal and Heliospheric Investigations (SECCHI) instrument suite on the NASA STEREO mission. The SECCHI on the two STEREO spacecraft are identical suites of remote sensing instruments designed to observe coronal mass ejections (CMEs) at the Sun and in transit outwards to 1 AU.EUVI measured emission lines at 30.4 nm (He II), 17.1 nm (Fe IX), 19.5 nm (Fe XII), and 21.1 nm (Fe XIV). The EUVI's 2048 x 2048 pixel detectors have a field of view out to 1.7 solar radii, and observe in four spectral channels that span the 0.1 to 20 MK temperature range. In addition to its view from two vantage points, the EUVI will provide a substantial improvement in image resolution and image cadence over its predecessor SOHO-EIT, while complying with the more restricted mass, power, and volume allocations on the STEREO mission.

The COR1 telescope is the inner coronagraph of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite aboard the twin Solar Terrestrial Relations Observatory (STEREO) spacecraft. Like all coronagraphs, COR1 is designed to measure the weak light from the solar corona in the presence of scattered light from the much brighter solar photosphere. It designed to observe the white light corona from 1.4 to 4 solar radii.

The COR1 telescope is the inner coronagraph of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite aboard the twin Solar Terrestrial Relations Observatory (STEREO) spacecraft. Like all coronagraphs, COR1 is designed to measure the weak light from the solar corona in the presence of scattered light from the much brighter solar photosphere. It designed to observe the white light corona from 1.4 to 4 solar radii.

The HRIIMAGE database table contains information from the High Resolution Imager aboard HEAO 2, the Einstein Observatory. Einstein incorporated a high-resolution X-ray telescope and a focal plane assembly capable of positioning at its focus one of four instruments: a high-resolution imaging detector (HRI), a broader-field imaging proportional counter (HRI), a solid state spectrometer (SSS), and a Bragg crystal spectrometer (FPCS). Einstein (HEAO 2) was launched on November 13, 1978, and operated successfully until April 1981. One duplicate entry was removed from the HEASARC implementation of this catalog in June 2019. This is a service provided by NASA HEASARC .

Heliocentric trajectories for STEREO-A in Heliographic, HG, Heliographic Inertial, HGI, and Solar Ecliptic, SE, Coordinates The original trajectory data are taken from http://ssd.jpl.nasa.gov/horizons.cgi where users can find many more objects. In the case of orbit data for planets, the orbit data can be used as a proxy for spacecraft ephemeris that are in orbit about the planets. On a heliospheric scale, differences between the planet orbital tarjectory and that of the spacecraft are very small. For instance, the heliocentric longitudes differ by only 0.25° for a spacecraft stationed near the L1 Lagrange point at approximately 100 Earth radii upstream of the Earth. The production of the HG, HGI, and SE trajectory data requires a values for the "Equinox Epoch", which is defined as the epoch time when the direction from the Earth to the sun at the time of the vernal equinox when the sun seems to cross equatorial plane of the Earth from below. This direction is called the First Point of Aries, FPA and it is not a fixed direction but drifts by about 1.4° per century or 50.26" per year. In addition, there are tiny irregularities in FPA drift that are on the order of 1" per year or less. The Equinox Epoch can be determined by using a variety of methods for calculating the instantaneous FPA longitudinal direction and whether the tiny irregularities have been smoothed or averaged out. Four methods for determining the Equinox Epoch are in common usage: +---------------------------------------------------------------------+ Method Name FPA Longitude Definition --------------------------------------------------------------------- B1950.0 the actual FPA at 22:09 UT on December 31, 1949 J2000.0 the smoothed FPA at 12:00 UT on January 1, 2000 True of Date the actual FPA at 00:00 UT on the date of interest Mean of Date the smoothed FPA at 00:00 UT on the date of interest +---------------------------------------------------------------------+ The heliocentric trajectory data included in this data product have been calculated by using the Equinox Epoch: defined via the "Mean of Date" method. More precise coordinates, and some planet-centered coordinates, are found in the "traj" subdirectories of spacecraft specific directories at https://spdf.gsfc.nasa.gov/pub/data/ and http://ssd.jpl.nasa.gov/horizons.cgi.

The NSSDC Coordinated Heliospheric Observations Web, COHOWeb, hourly and daily Solar-Terrestrial Relations Observatory-A, STEREO-B, data were made by using high resolution data from from CDAWeb. The STEREO-A COHO file include data derived from the STEREO-A In-Situ Measurements of Particles and CME Transients, IMPACT, Fluxgate Magnetometer data, Thermal Plasma Moments: Solar Wind Proton and Ion Densities, Speeds, Velocity Vector Flow Angles, and Temperatures from the STEREO-A Plasma and Supra-Thermal Ion Composition, PLASTIC, Instrument, and Energetic Particle Fluxes from the STEREO-A IMPACT Solar Energetic Particle, SEP, Instrument Suite including the Low Energy Telescope, LET, High Energy Telescope, HET, and Suprathermal Ion Telescope, SIT. COHOWeb's magnetic field hourly averages were created at GSFC/SPDF by averaging over the six 10-min averages falling within each hour. Hourly plasma parameter data were obtained from UNH via http://fiji.sr.unh.edu/1dmax_ascii/.