29 research outputs found
Orbiting astronomical observatory Final report /including status reports for 1 Dec. 1967 - 30 Jun. 1968 and 1 Jul. 1968 - 31 Mar. 1969/
Research activities of Lunar and Planetary Laborator
Infrared Instrumentation and Astronomy
Contains reports on five research projects.Joint Services Electronics Program (Contract DAAB07-76-C-1400)National Aeronautics and Space Administration (Grant NGR 22-009-526)National Aeronautics and Space Administration (Grant NSG-7328)National Aeronautics and Space Administration (Contract NAS5-24096
Explaining prehistoric variation in the abundance of large prey: A zooarchaeological analysis of deer and rabbit hunting along the Pecho Coast of Central California
Solar origins of a strong stealth CME detected by Solar Orbiter
Aims.We aim to locate the origin of a stealth coronal mass ejection (CME)
detected in situ by the MAG instrument on board Solar Orbiter, and make
connections between the CME observed at the Sun, and the interplanetary CME
(ICME) measured in situ. Methods. Remote sensing data are analysed using
advanced image processing techniques to identify the source region of the
stealth CME, and the global magnetic field at the time of the eruption is
examined using Potential Field Source Surface (PFSS) models. The observations
of the stealth CME at the Sun are compared with the magnetic field measured by
the Solar Orbiter spacecraft, and plasma properties measured by the Wind
spacecraft. Results. The source of the CME is found to be a quiet Sun cavity in
the northern hemisphere. We find that the stealth CME has a strong magnetic
field in situ, despite originating from a quiet Sun region with an extremely
weak magnetic field. Conclusions. The interaction of the ICME with its
surrounding environment is the likely cause of a higher magnetic field strength
measured in situ. Stealth CMEs require multi-wavelength and multi-viewpoint
observations in order to confidently locate the source region, however their
elusive signatures still pose many problems for space weather forecasting. The
findings have implications for Solar Orbiter observing sequences with
instruments such as EUI that are designed to capture stealth CMEsComment: 6 pages, 7 figures, accepted for publication in A&