The large stellar association cataloged as NGC 206 is nestled within the dusty arms of the neighboring Andromeda galaxy. Also known as M31, the spiral galaxy is a mere 2.5 million light-years away. NGC 206 is seen in this gorgeous close-up of the southwestern extent of Andromeda’s disk, a remarkable composite of data from space and ground-based observatories. The bright, blue stars of NGC 206 indicate its youth. In fact, its youngest massive stars are less than 10 million years old. Much larger than the open or galactic clusters of young stars in the disk of our Milky Way galaxy, NGC 206 spans about 4,000 light-years. That’s comparable in size to the giant stellar nurseries NGC 604 in nearby spiral M33 and the Tarantula Nebula, in the Large Magellanic Cloud. Star forming sites within Andromeda are revealed by the telltale reddish emission from clouds of ionized hydrogen gas.

Object Names: M31, NGC 206

Image Type: Astronomical

Credit: Subaru Telescope (NAOJ), Hubble Space Telescope, Local Group Galaxy Survey (Phil Massey PI), Mayall 4-Meter, Robert Gendler

Time And Spce

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SIRIUS is the brightest star in the night sky. It is found in the constellation Canis Major and is located 8.6 light years from Earth. It is part of a star system consisting of Sirius A and Sirius B. The Sirius star system is one of Earth’s near neighbours and is sometimes referred to as the “Dog Star”.

Sirius A is a main sequence star and Sirius B is a white dwarf. The distance separating the two stars is between 8.2 to 31.5 Astronomical Units (AU). The distance between the Sun and the Earth is 1 AU.

Sirius is about twice as massive as the Sun and is about 25 times more luminous. The system started off as two bright blue stars. The brighter of the two (Sirius B), consumed its resources faster, became a red giant, and shed it’s outer layers to become the current white dwarf that it is today.

Sirius is gradually moving towards the Solar System so over time it’ll slightly increase in brightness (over the next 60 000 years). Once it reaches a certain distance from the Solar System, it’ll begin to move away, becoming fainter. It will remain the brightest star in the sky for the next 210 000 years.

Got any other questions/facts about Sirius? Send me a message and we can talk about it!

TOMORROW marks the final week, WEEK 4 of Space Month! Can anyone guess what the last theme will be?

The North America and Pelican Nebulas : Here lie familiar shapes in unfamiliar locations. On the left is an emission nebula cataloged as NGC 7000, famous partly because it resembles our fair planet’s continent of North America. The emission region to the right of the North America Nebula is IC 5070, also known for its suggestive outlines as the Pelican Nebula. Separated by a dark cloud of obscuring dust, the two bright nebulae are about 1,500 light-years away. At that distance, the 4 degree wide field of view spans 100 light-years. This spectacular cosmic portrait combines narrow band images to highlight bright ionization fronts with fine details of dark, dusty forms in silhouette. Emission from atomic hydrogen, sulfur, and oxygen is captured in the narrow band image in scientifically assigned colors. These nebulae can be seen with binoculars from a dark location. via NASA

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Summer Planets and Milky Way

(via APOD; Image Credit & Copyright: Tunç Tezel (TWAN) )

Lights sprawl toward the horizon in this night skyscape from Uludag National Park, Bursa Province, Turkey, planet Earth. The stars and nebulae of the Milky Way are still visible though, stretching above the lights on the northern summer night while three other planets shine brightly. Jupiter is at the far right, Mars near the center of the frame, and Saturn is just right of the bulging center of our galaxy. Because the panoramic scene was captured on July 6, all three planets pictured were hosting orbiting, operational, robotic spacecraft from Earth. Popular Mars has five (from three different space agencies): MAVEN (NASA), Mars Orbiter Mission (India), Mars Express (ESA), Mars Odyssey (NASA), Mars Reconnaissance Orbiter (NASA). Ringed Saturn hosts the daring Cassini spacecraft. Just arrived, Juno now orbits ruling gas giant Jupiter.

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Ask Ethan: Will The ‘Great Attractor’ Defeat Dark Energy?

“If we are only ultimately bound to [Andromeda], and everything else will eventually slip out of our visible universe, how can all the we all be heading to the great attractor (or whatever we’re all heading towards at the gravitational center of Laniakea)?”

When dark energy was discovered, and the expansion of the Universe was shown to be accelerating, there was concurrently another puzzle that received much less attention: the problem of the Great Attractor. Galaxies appear to move due to both the Hubble expansion and the local gravitational field, but the gravity from the galaxies we saw didn’t account for all the motion. There must have been an additional set of masses, revealed only in the 2010s with the identification of the supercluster Laniakea. All the galaxies in our local neighborhood are headed towards it, but are we moving fast enough to overcome the expansive pull of dark energy?

The answer looks to be no; come find out why on this week’s Ask Ethan!