Daily Archives: August 26, 2014

The Sun Online and solar activity. August 26, 2014

Flaring activity continued at the same level with four C- and two M-class flares, originating from NOAA AR 2146. Two CMEs were observed in coronographic imagery, with NOAA AR 2146 as source region.
An asymmetric halo CME was visible in SOHO/LASCO C2 and C3 and STEREO B/COR2 data, with first measurements on August 25 at 15:24 UT (C2), 16:18 UT (C3) and 16:24 UT (STEREO B)  respectively. The CME was associated with a M2 flare peaking at 15:11 UT, dimming and type II and IV
radio bursts (shock speed estimated at 707 km/s by the Sagamore Hill station). The CME has a projected line-of-sight speed of 568 km/s (CACTus estimate). A second partial halo CME was visible in SOHO/LASCO C2 and C3, with first measurements on August 25 at 20:36 UT (C2) and 21:18 UT (C3). Also this CME was associated with an M-class flare (M3.9, peak at 20:21 UT). The CME is travelling with a projected line-of-sight speed of 761 km/s (CACTus estimate).
Both CMEs are mainly propagating in the western direction from the Sun-Earth line and might be interacting with each other. A shock might arrive in the second half of the UT day of August 28.  
More C- and M-class flares are expected, especially from NOAA ARs 2146 and 2149. An X-class flare is possible, but unlikely. Proton flux levels at > 10MeV have increased from 18:00 UT on, but remained
below the event threshold and are currently decreasing. A warning condition for a proton event, in case of more flaring, is issued. Solar wind speed slightly increased from 250 till 290 km/s. The amplitude of the
interplanetary magnetic field increased to 7 nT, with a varying Bz component. Geomagnetic conditions were quiet to unsettled and are expected to remain so until the combined arrival of the August 22 CME’s. This may potentially result in active geomagnetic conditions from the afternoon of August 26 onwards.


Flying Past Neptune’s Moon Triton 

Image Credit: Voyager 2, JPL, NASA; Digital composition: Paul Schenk (LPI, USRA)

 What would it look like to fly past Triton, the largest moon of planet Neptune? Only one spacecraft has ever done this – and now, for the first time, images of this dramatic encounter have been gathered into a movie. On 1989 August 25, the Voyager 2 spacecraft shot through the Neptune system with cameras blazing. Triton is slightly smaller than Earth’s Moon but has ice volcanoes and a surface rich in frozen nitrogen. The first sequence in the video shows Voyager’s approach to Triton, which, despite its unusual green tint, appears in approximately true color. The mysterious terrain seen under the spacecraft soon changed from light to dark, with the terminator of night soon crossing underneath. After closest approach, Voyager pivoted to see the departing moon, now visible as a diminishing crescent. Next July, assuming all goes well, the robotic New Horizons spacecraft will make a similar flight past Pluto, an orb of similar size to Triton.

APOD NASA 26-Aug-14

NGC 891 in Andromeda

NGC 891
 (also known as Caldwell 23) is an edge-on unbarred spiral galaxy about 30 million light-years away in the constellation Andromeda. It was discovered by William Herschel on October 6, 1784. The galaxy is a member of the NGC 1023 group of galaxies in the Local Supercluster. It has an H II nucleus. The object is visible in small to moderate size telescopes as a faint elongated smear of light with a dust lane visible in larger apertures. In 1999, the Hubble Space Telescope imaged NGC 891 in infrared. In 2005, due to its attractiveness and scientific interest, NGC 891 was selected to be the first light image of the Large Binocular Telescope. In 2012, it was again used as a first light image of the Discovery Channel Telescope with the Large Monolithic Imager.

Imaging cameras: Canon 20Da, Artemis Atik 383L+
Mounts: Vixen New Atlux + Skysensor 2000
Guiding telescopes or lenses: Orion Optics UK SPX 250
Guiding cameras: M-Gen Guiding Kamera
Focal reducers: GPU Komakorrektor
Software: Adobe Photoshop CS2, DSS, Fitswork
Filters: Baader Planetarium 36mm Luminance
Accessories: Lacerta MGEN2, Lacerta OAG
Dates: Oct. 1, 2013, Oct. 2, 2013, Oct. 7, 2013, Oct. 24, 2013
Locations: Kreben
75×600″ ISO400
Baader Planetarium 36mm Luminance: 16×360″ -20C bin 1×1
Integration: 14.1 hours
Darks: ~12
Flats: ~139

Author: Stefan Westphal
AstroPhotography of the day by SPONLI 26 Aug 2014