The STEREO Mission: An Introduction

Abstract

The twin STEREO spacecraft were launched on October 26, 2006, at 00:52 UT from Kennedy Space Center aboard a Delta 7925 launch vehicle. After a series of highly eccentric Earth orbits with apogees beyond the moon, each spacecraft used close flybys of the moon to escape into orbits about the Sun near 1 AU. Once in heliospheric orbit, one spacecraft trails Earth while the other leads. As viewed from the Sun, the two spacecraft separate at approximately 44 to 45 degrees per year. The purposes of the STEREO Mission are to understand the causes and mechanisms of coronal mass ejection (CME) initiation and to follow the propagation of CMEs through the inner heliosphere to Earth. Researchers will use STEREO measurements to study the mechanisms and sites of energetic particle acceleration and to develop three-dimensional (3-D) time-dependent models of the magnetic topology, temperature, density and velocity of the solar wind between the Sun and Earth. To accomplish these goals, each STEREO spacecraft is equipped with an almost identical set of optical, radio and in situ particles and fields instruments provided by U.S. and European investigators. The SECCHI suite of instruments includes two white light coronagraphs, an extreme ultraviolet imager and two heliospheric white light imagers which track CMEs out to 1 AU. The IMPACT suite of instruments measures in situ solar wind electrons, energetic electrons, protons and heavier ions. IMPACT also includes a magnetometer to measure the in situ magnetic field strength and direction. The PLASTIC instrument measures the composition of heavy ions in the ambient plasma as well as protons and alpha particles. The S/WAVES instrument uses radio waves to track the location of CME-driven shocks and the 3-D topology of open field lines along which flow particles produced by solar flares. Each of the four instrument packages produce a small real-time stream of selected data for purposes of predicting space weather events at Earth. NOAA forecasters at the Space Environment

The magnetic field configuration of a solar prominence inferred from spectropolarimetric observations in the He i 10 830 Å triplet

“…To put the TIP-II observations in context, we made use of data provided by the extreme ultraviolet light telescope (AIA; Lemen et al 2012) onboard NASA's Solar Dynamics Observatory (SDO; Pesnell et al 2012), the Solar Terrestrial Relations Observatory (STEREO-B) Extreme UltraViolet Imager (Kaiser et al 2008), and the Big Bear Solar Observatory (BBSO) high-resolution H α filter (Denker et al 1999). Figure 2 displays maps of the prominence as seen in the Fe ix 171 Å, Fe xiv 211 Å, and He ii 304 Å AIA band passes (top panels).…”

3D Evolution of a Filament Disappearance Event Observed by STEREO

“…The disadvantage of this method being: (i) it measures only the projected height, (ii) non-availability of magnetograms due to its location at the limb, (iii) can not be used to follow height evolution for several days and (iv) no continuity of multi-temperature observations. Only recently, with the advent of stereoscopic observations by the twin spacecraft of the Solar Terrestrial Relations Observatory (STEREO) mission called STEREO-A (Ahead) and STEREO-B (Behind), the true height of filament can be judged properly and the heating of the plasma can be tested (Kaiser et al, 2008); (Gissot et al, 2008); (Liewer et al, 2009).…”

SDO/AIA and Hinode/EIS observations of interaction between an EUV wave and active region loops

“…This was independently confirmed by numerical simulations of Wang (2000), Wu (2001) and Ofman & Thompson (2002). EUV waves were observed by the EUV Imagers (EUVI; Wuelser et al 2004) on board the Solar-Terrestrial Relations Observatory (STEREO; Kaiser et al 2008) to be reflected from CHs (Gopalswamy et al 2009). This was further confirmed from higher cadence and sensitivity observations by SDO/AIA (Li et al 2012;Shen & Liu 2012).…”