Hubble’s Tuning Fork and Galaxy Classification
Coincident with his discovery of Cepheid stars in Andromeda, Edwin Hubble was working in the mid 1920s to study other galaxies in more detail (although at that point it was still common terminology to refer to them as nebulae). It is often the case with the discovery of a new class of objects that astronomers invent a classification scheme as a first step to try to understand these objects. Hubble is credited with creating a classification scheme for galaxies, which is usually referred to as his “Tuning Fork” diagram.
A few telescopic surveys were done to determine the different types of galaxies, one of them was called the “SINGS” survey”
and the other called “KINGFISH”:
And now for some obligatory space photos, which can all be found HERE:
Two decades ago, astronomers spotted one of the brightest exploding stars in more than 400 years.
Since that first sighting, the doomed star, called Supernova 1987A, has continued to fascinate astronomers with its spectacular light show. NASA’s Hubble Space Telescope is one of many observatories that has been monitoring the blast’s aftermath.
This image shows the entire region around the supernova. The most prominent feature in the image is a ring with dozens of bright spots. A shock wave of material unleashed by the stellar blast is slamming into regions along the ring’s inner regions, heating them up, and causing them to glow. The ring, about a light-year across, was probably shed by the star about 20,000 years before it exploded.
Spiral Galaxy NGC 4622 Spins “Backwards”:
Astronomers have found a spiral galaxy that may be spinning to the beat of a different cosmic drummer.
To the surprise of astronomers, the galaxy, called NGC 4622, appears to be rotating in the opposite direction to what they expected..
Ring of Hot Blue Stars Pinwheels Around Yellow Nucleus of Hoag’s Object Galaxy:
Two galaxies swing past each other in a graceful performance choreographed by gravity. This is one of hundreds of interacting and merging galaxies known in our nearby universe:
Hubble-Magellan Composite of M83:
Pandora’s Cluster – Abell 2744:
Star V838 Monocerotis (V838 Mon):
When a massive star exploded, spewing out its gaseous layers into a turbulent, star-forming region of the Large Magellanic Cloud, it left behind this chaotic cloud of gas and dust. The star that produced this supernova remnant was probably 50 times the mass of our Sun:
Cassiopeia A: Colorful, Shredded Remains of Old Supernova:
Multiple Impacts From Comet P/Shoemaker-Levy 9 on Jupiter:
Bright Clouds on Uranus:
Saturn’s Ultraviolet Aurora:
Hubble Shows that Jupiter’s Great Red Spot Is Smaller than Ever Seen Before:
In this image by NASA’s Hubble Space Telescope, an unusual, ghostly green blob of gas appears to float near a normal-looking spiral galaxy:
Looking like an apparition rising from whitecaps of interstellar foam, the iconic Horsehead Nebula has graced astronomy books ever since its discovery over a century ago:
Dark Globule and Stellar Jet in the Carina Nebula:
The tadpole-looking feature in the center of this image is a nodule of cold hydrogen gas laced with dust.
Close Up of Ancient, White Dwarf Stars in the Milky Way Galaxy:
A planetary nebula called NGC 5189. The intricate structure of this bright gaseous nebula resembles a glass-blown holiday ornament with a glowing ribbon entwined:
The Bug Nebula, NGC 6302, is one of the brightest and most extreme planetary nebulae known. The fiery, dying star at its center is shrouded by a blanket of icy hailstones. This NASA Hubble Wide Field Plantery Camera 2 image shows impressive walls of compressed gas, laced with trailing strands and bubbling outflows:
Celestial Fireworks: Sheets of Debris From a Stellar Explosion (N 49, DEM L 190):
This is a false-color view of a planetary debris disk encircling the star HD 107146, a yellow dwarf star very similar to our Sun, this is the only disk to have been imaged around a star so much like our own.
Hubble Supernova Bubble Resembles Holiday Ornament:
The Veil Nebula, left behind by the explosion of a massive star thousands of years ago, is one of the largest and most spectacular supernova remnants in the sky. This is only a small section of it:
Hubble Sees a Cosmic Caterpillar:
The Necklace Nebula:
Saturn’s Dynamic Auroras:
Doomed Star Eta Carinae:
Hubble Space Telescope Image of Globular Cluster NGC 6397
Anything that ever happened, to anyone, in all of history happened here:
I feel that any astronomy thread should have a star size chart/video included, so here again is the complimentary star size guide: