Antonio Vivaldi - "Outono" - Video - Musica

"Outono"

Equinox: Analemma over the Callanish Stones - Astronomy picture of the day - 2018 September 23

Equinox: Analemma over the Callanish Stones 
Image Credit & Copyright: Giuseppe Petricca

Explanation: Does the Sun return to the same spot on the sky every day at the same time? No. A more visual answer to that question is an analemma, a composite image taken from the same spot at the same time over the course of a year. The featured analemma was composed from images taken every few days at 4 pm near the village of Callanish in the Outer Hebrides in Scotland, UK. In the foreground are the Callanish Stones, a stone circle built around 2700 BC during humanity's Bronze Age. It is not known if the placement of the Callanish Stones has or had astronomical significance. The ultimate causes for the figure-8 shape of this an all analemmas are the tilt of the Earth axis and theellipticity of the Earth's orbit around the Sun. At the solstices, the Sun will appear at the top or bottom of an analemma. Equinoxes, however, correspond to analemma middle points -- not the intersection point. Today at 1:54 am (UT) is the equinox ("equal night"), when day and night are equal over all of planet Earth. Many cultures celebrate a change of season at an equinox.

Window Seat over Hudson Bay - Astronomy picture of the day - 2018 September 22

Window Seat over Hudson Bay 
Image Credit & Copyright: Ralf Rohner

Explanation: On the August 18 night flight from San Francisco to Zurich, a window seat offered this tantalizing view when curtains of light draped a colorful glow across the sky over Hudson Bay. Constructed by digitally stacking six short exposures made with a hand held camera, the scene records the shimmering aurora borealis or northern lights just as the approaching high altitude sunrise illuminated the northeastern horizon. It also caught the flash of a Perseidmeteor streaking beneath the handle stars of the Big Dipper of the north. A few days past the meteor shower's peak, its trail still points across the sky toward Perseus. Beautiful aurorae and shower meteors both occur in Earth's upper atmosphere at altitudes of 100 kilometers or so, far above commercial airline fights. The aurora are caused by energetic charged particles from the magnetosphere, while meteors are trails of comet dust.

Irregular Galaxy NGC 55 - Astronomy picture of the day - 2018 September 21

Irregular Galaxy NGC 55 
Image Credit & Copyright: Martin Pugh

Explanation: Irregular galaxy NGC 55 is thought to be similar to the Large Magellanic Cloud (LMC). But while the LMC is about 180,000 light-years away and is a well known satellite of our own Milky Way Galaxy, NGC 55 is more like 6 million light-years distant and is a member of the Sculptor Galaxy Group. Classified as an irregular galaxy, in deep exposures the LMC itself resembles a barred disk galaxy. Spanning about 50,000 light-years, NGC 55 is seen nearly edge-on though, presenting a flattened, narrow profile in contrast with our face-on view of the LMC. Just as large star forming regions create emission nebulae in the LMC, NGC 55 is also seen to be producing new stars. This highly detailed galaxy portrait highlights a bright core crossed with dust clouds, telltale pinkish star forming regions, and young blue star clusters in NGC 55.

The Piano Guys - "Beethoven's Five Secrets - One Republic" Video - Music - Live

"Beethoven's Five Secrets - One Republic"

Stars and Dust in Corona Australis - Astronomy picture of the day - 2018 September 20

Stars and Dust in Corona Australis 
Image Credit & Copyright: Josep Drudis

Explanation: Cosmic dust clouds and young, energetic stars inhabit this telescopic vista, less than 500 light-years away toward the northern boundary of Corona Australis, the Southern Crown. The dust clouds effectively block lightfrom more distant background stars in the Milky Way. But the striking complex of reflection nebulae cataloged as NGC 6726, 6727, and IC 4812 produce a characteristic color as blue light from the region's young, hot stars isreflected by the cosmic dust. The dust also obscures from view stars still in the process of formation. At top right, smaller yellowish nebula NGC 6729 bends around young variable star R Coronae Australis. Near it, glowing arcs and loops shocked by outflows from embedded newborn stars are identified as Herbig-Haro objects. On the sky this field of view spans about 1 degree. That corresponds to almost 9 light-years at the estimated distance of the nearby star forming region.

Cocoon Nebula Deep Field - Astronomy picture of the day - 2018 September 19

Cocoon Nebula Deep Field 
Image Credit & Copyright: Marcel Drechsler (Baerenstein Obs.)

Explanation: Inside the Cocoon Nebula is a newly developing cluster of stars. The cosmic Cocoon on the upper right also punctuates a long trail of obscuring interstellar dust clouds to its left. Cataloged as IC 5146, the beautiful nebula is nearly 15 light-years wide, located some 3,300 light years away toward the northern constellation of the Swan (Cygnus). Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by young, hot stars and blue, dust-reflected starlight at the edge of a nearly invisible molecular cloud. In fact, the bright star near the center of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it slowly clears out a cavity in the molecular cloud's star forming dust and gas. This exceptionally deep color view of the Cocoon Nebula traces tantalizing features within and surrounding the dusty stellar nursery.

Cosmic Collision Forges Galactic Ring - Astronomy picture of the day - 2018 September 17

Cosmic Collision Forges Galactic Ring  Image Credit: X-ray: Chandra (NASA, CXC, INAF, A. Wolter et al.); Optical: Hubble (NASA, STScI) Explanation: How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars. That galaxy, AM 0644-741, is known as a ring galaxy and was caused by an immense galaxy collision. When galaxies collide, they pass through each other -- their individual stars rarely come into contact. The ring-like shape is the result of the gravitational disruption caused by an entire small intruder galaxy passing through a large one. When this happens, interstellar gas and dust become condensed, causing a wave of star formation to move out from the impact point like a ripple across the surface of a pond. The likely intruder galaxy is on the left of this combined image from Hubble (visible) and Chandra (X-ray) space telescopes. X-ray light is shown in pink and depicts places where energetic black holes or neutron stars, likely formed shortly after the galaxy collision, reside.

Ravel - "Bolero" - (Prequell Rework) - Video - Music

"Boléro"

A Solar Filament Erupts - Astronomy picture of the day - 2018 September 16

A Solar Filament Erupts 
Image Credit: NASA's GSFC, SDO AIA Team

Explanation: What's happened to our Sun? Nothing very unusual -- it just threw a filament. Toward the middle of 2012, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME). The filament had been held up for days by the Sun's ever changing magnetic field and the timing of the eruption was unexpected. Watched closely by the Sun-orbiting Solar Dynamics Observatory, the resulting explosion shotelectrons and ions into the Solar System, some of which arrived at Earth three days later and impacted Earth's magnetosphere, causing visible aurorae. Loops of plasma surrounding an active region can be seen above the erupting filament in the featured ultraviolet image. Although the Sun is now in a relatively inactive state of its 11-year cycle, unexpected holes have opened in the Sun's corona allowing an excess of charged particles to stream into space. As before, these charged particles are creating auroras.