Daily Archives: April 25, 2014

Hubble’s Messier 5 

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Image Credit: 
HST, ESA, NASA

“Beautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] …” begins the description of the 5th entry in 18th century astronomer Charles Messier’s famous catalog of nebulae and star clusters. Though it appeared to Messier to be fuzzy and round and without stars, Messier 5 (M5) is now known to be a globular star cluster, 100,000 stars or more, bound by gravity and packed into a region around 165 light-years in diameter. It lies some 25,000 light-years away. Roaming the halo of our galaxy, globular star clusters are ancient members of the Milky Way. M5 is one of the oldest globulars, its stars estimated to be nearly 13 billion years old. The beautiful star cluster is a popular target for Earthbound telescopes. Of course, deployed in low Earth orbit on April 25, 1990, the Hubble Space Telescope has also captured its own stunning close-up view that spans about 20 light-years near the central region of M5. Even close to its dense core at the left, the cluster’s aging red and blue giant stars and rejuvenated blue stragglers stand out in yellow and blue hues in the sharp color image.

NASA APOD 25-Apr-14

Sharpless 2-308

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Sharpless 2-308 it lies some 5,200 light-years away toward the constellation of the Big Dog (Canis Major) and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun.

Imaging telescopes or lenses: Astro-Physics 152mm f/7.5 Starfire EDF
Imaging cameras: FLI ProLine Proline 16803
Mounts: Software Bisque Paramount MX
Guiding telescopes or lenses: Takahashi FS-60C
Guiding cameras: Starlight Xpress Superstar
Focal reducers: Astro-Physics AP 4.0″ Field Flattener
Software: PixInsight 1.8, Software Bisque TheSky6 Professional, FocusMax, Cyanogen Maxim DL Pro 5, Photoshop CS Photo Shop CS5, CCD Autopilot 5
Filters: Astrodon E-series LRGB Ha 5nm
Accessories: Sirius Dome
Dates: Feb. 21, 2014
Locations: Sydney Australia
Frames: 19×1200″
Integration: 6.3 hours

Author: David Nguyen
AstroPhotography of the day by SPONLI
25 April 2014

The Sun Online and solar activity. April 24, 2014

Six low-level C-class flares were recorded over the last 24 hours, mostly produced by active region NOAA 2035 which was also the source of the strongest event (C5 peaking at 13:06UT). NOAA 2044 was the only other region producing a flare (C3 peaking at 23:53UT). Imagery from the SOHO and STEREO coronagraphs indicate that the associated CMEs are directed away from the Earth, with any glancing blow not expected to affect the geomagnetic field significantly.

There’s still a chance on a C-class flare. Dourbes recorded a brief period of active geomagnetic conditions
(00:00-03:00UT; K=4; Kp=3). The source of this disturbance is uncertain, with no obvious signature in the solar wind (ACE). For the remainder of the period, quiet geomagnetic conditions were observed. Solar wind speed oscillated between 400 and 450km/s, with Bz varying between -6 and +5nT. A small equatorial coronal hole passed the central meridian last night. The geomagnetic field may be impacted starting around 27 April.
Geomagnetic conditions are expected to be quiet.
 
SIDC