Two partial halo CMEs were detected today, first appearing in the SOHO/LASCO C2 field of view at 00:36 and 09:24 UT respectively. Their angular widths were similar (around 150 and 130 degrees respectively), as well as were their shapes, although the first one was significantly weaker than the second one. Both CMEs seem to result from activity in the active region on the far side of the Sun (around N10W130) as observed by STEREO/EUVI, so none of them is expected to arrive at the Earth.
Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Time UT: 16:00
Exposure 1/500 sec.
Image Credit & Copyright: Jeff Dai
Why would the sky look like a giant target? Airglow. Following a giant thunderstorm over Bangladesh in late April, giant circular ripples of glowing air appeared over Tibet, China, as pictured above. The unusual pattern is created by atmospheric gravity waves, waves of alternating air pressure that can grow with height as the air thins, in this case about 90 kilometers up. Unlike auroras powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction. More typically seen near the horizon, airglow keeps the night sky from ever being completely dark.
APOD NASA 01-Sep-14
IC 5146 (also Caldwell 19, Sh 2-125, and the Cocoon Nebula) is a reflection/emission nebula and Caldwell object in the constellation Cygnus. The NGC description refers to IC 5146 as a cluster of 9.5 mag stars involved in a bright and dark nebula. The cluster is also known as Collinder 470. It shines at magnitude +10.0/+9.3/+7.2. Its celestial coordinates are RA 21h 53.5m, dec+47° 16′. It is located near the naked-eye star Pi Cygni, the open cluster NGC 7209 in Lacerta, and the bright open clusterM39. The cluster is about 4,000 ly away, and the central star that lights it formed about 100,000 years ago; the nebula is about 12 arcmins across, which is equivalent to a span of 15 light years. When viewing IC 5146, dark nebula Barnard 168 (B168) is an inseparable part of the experience, forming a dark lane that surrounds the cluster and projects westward forming the appearance of a trail behind the Cocoon.
Imaging telescopes or lenses: Takahashi TSA-102
Imaging cameras: Atik 383L+ mono
Mounts: SkyWatcher NEQ6 pro II
Guiding telescopes or lenses: EZG60
Guiding cameras: QHYCCD QHY5 Mono
Focal reducers: Takahashi TOA-35
Software: Pleiades Astrophoto, S.L. PixInsinght 1.8 RC7
Filters: Baader Planetarium G 2″, Baader Planetarium R 2″, Baader Planetarium B 2″
Dates: July 29, 2014
Baader Planetarium B 2″: 11×600″ bin 1×1
Baader Planetarium G 2″: 11×600″ bin 1×1
Baader Planetarium R 2″: 11×600″ bin 1×1
Integration: 5.5 hours
Author: Jose Luis Ricote
AstroPhotography of the day by SPONLI 01 Sep 2014