Object: NGC6210
FITS data obtained from Hubble Legacy Archive (HLA).
Processing by: Delio Tolivia Cadrecha
NGC6210 is planetary nebula located in the constellation of Hercules.
55
NGC3584 (narrowband) in Carina. — Desert Hollow Observatory
This beautiful, glittering swirl is named, rather unpoetically, J125013.50+073441.5. A glowing haze of material seems to engulf the galaxy, stretching out into space in different directions and forming a fuzzy streak in this image.
It is a starburst galaxy — a name given to galaxies that show unusually high rates of star formation. The regions where new stars are being born are highlighted by sparkling bright blue regions along the galactic arms.
Studying starburst galaxies can tell us a lot about galactic evolution and star formation. These galaxies start off with huge amounts of gas, which is used to form new stars.
This period of furious star formation is only a phase; once all the gas is used up, this starbirth slows down. Other famous starbursts captured by Hubble include the Antennae Galaxies (heic0615) and Messier 82 (heic0604), the latter of which is forming new stars ten times faster than our galaxy, the Milky Way.
The 4th dimension in our case is where the 3D structures including this very Universe combine and exist within changing time frames. 4D structures can’t exist within 3D ones but 3D structures can exist in a 4D just like your drawings exist within that flat paper as lines and points but couldn’t exist in our 3D world by itself. Extra dimensions work the same, like a Matryoshka doll that loses and or gains properties the further you go.
Image: 3D projection of a tesseract undergoing a simple rotation in four dimensional space.
In mathematical physics, Minkowski space or Minkowski spacetime (named after the mathematician Hermann Minkowski) is the mathematical space setting in which Einstein’s theory of special relativity is most conveniently formulated. In this setting the three ordinary dimensions of space are combined with a single dimension of time to form a four-dimensional manifold for representing a spacetime. [**]
In physics, spacetime (also space–time, space time or space–time continuum) is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space as existing in three dimensions and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions. From a Euclidean space perspective, the universe has three dimensions of space and one of time. By combining space and time into a single manifold, physicists have significantly simplified a large number of physical theories, as well as described in a more uniform way the workings of the universe at both the supergalactic and subatomic levels. [**]
But my favorite explanation of extra dimensions in general is Carl Sagan’s version. His version was based on Flatland: A Romance of Many Dimensions which is an 1884 satirical short story by Edwin Abbott Abbott:
The story is about a two-dimensional world referred to as Flatland which is occupied by geometric figures. Women are simple line-segments, while men are polygons with various numbers of sides. The narrator is a humble square, a member of the social caste of gentlemen and professionals in a society of geometric figures, who guides us through some of the implications of life in two dimensions. The Square has a dream about a visit to a one-dimensional world (Lineland) which is inhabited by “lustrous points”.
He attempts to convince the realm’s ignorant monarch of a second dimension but finds that it is essentially impossible to make him see outside of his eternally straight line.
He is then visited by a three-dimensional sphere, which he cannot comprehend until he sees Spaceland for himself. This Sphere (who remains nameless, like all characters in the novella) visits Flatland at the turn of each millennium to introduce a new apostle to the idea of a third dimension in the hopes of eventually educating the population of Flatland of the existence of Spaceland. From the safety of Spaceland, they are able to observe the leaders of Flatland secretly acknowledging the existence of the sphere and prescribing the silencing of anyone found preaching the truth of Spaceland and the third dimension. After this proclamation is made, many witnesses are massacred or imprisoned (according to caste).
After the Square’s mind is opened to new dimensions, he tries to convince the Sphere of the theoretical possibility of the existence of a fourth (and fifth, and sixth …) spatial dimension.
The depiction above is a 4 dimensional figure as represented by 3 dimensional cubes within cubes to visualize how 4th dimensions may work.
Related: Carl Sagan explains extra dimensions
This image was obtained with the wide-field view of the Mosaic camera on the Mayall 4-meter telescope at Kitt Peak National Observatory.
LDN 810 is a dark nebula that was first cataloged by B.T. Lynds in 1962. The dark region at the center contains gas and dust out of which new stars are forming. A bipolar outflow of gas from one of these stars has also been detected.
A faint trail of dust and gas extends from the center of the image to the upper-left corner. The image was generated with observations in the Us (violet), B (blue), V (green) and I (red) filters. In this image, North is up, East is to the left.
Messier 94: Galactic Wheels within Wheels
How many rings do you see in this striking new image of the galaxy Messier 94 (NGC 4736) as seen by the infrared eyes of NASA’s Spitzer Space Telescope? While at first glance one might see a number of them, astronomers believe there is just one.
Historically, Messier 94 was considered to have two strikingly different rings: a brilliant, compact band encircling the galaxy’s core, and a faint, broad, swath of stars falling outside its main disk.
Astronomers have recently discovered that the outer ring, seen here in the deep blue glow of starlight, may actually be more of an optical illusion. Their 2009 study combined infrared Spitzer observations with ultraviolet data from NASA’s Galaxy Evolution Explorer, and ground-based surveys in visible (Sloan Digital Sky Survey) and near infrared light (Two Micron All Sky Survey). This more complete picture of Messier 94 indicates that we are really seeing two separate spiral arms that, from our perspective, take on the appearance of a single, unbroken ring.
The bright inner ring of Messier 94 is very real, however. This area is sometimes identified as a “starburst ring” because of the frenetic pace of star formation in this confined area. Starbursts like this can often be triggered by gravitational encounters with other galaxies, but in this case may instead be caused by the galaxy’s oval shape.
Tucked in between the inner starburst ring and the outer ring-like arms we find the galaxy’s disk, striated with greenish filaments of dust. While, at first glance, these dusty arcs look like a collection of rings, they actually follow tightly wound spiral arcs.
Messier 94 is about 17 million light years away, making it a distant neighbor of our own Milky Way galaxy. It was first discovered by Charles Messier’s assistant, Pierre Méchain, in 1781 and was added to his supervisor’s famous catalog two days later.
M8 and M20 in CFHT Filters — Cesar Blanco
HD 44179 - Red Rectangle Nebula
24 October 2006 - FITS data obtained from Hubble Legacy Archive (HLA). RGB integrated with a pseudo green. — Steven Marx
The Violent Violet Sun
“After dodging clouds and hailstorms all week I was able to record my first solar image at the CaK wavelength… 393.37nm in the violet end of the spectrum. I see almost no detail visually due to my eye’s poor sensitivity at this wavelength. But the camera sees good!” — Alan Friedman
Black Hole Powered Jets Plow Into Galaxy
This composite image of a galaxy illustrates how the intense gravity of a supermassive black hole can be tapped to generate immense power. The image contains X-ray data from NASA’s Chandra X-ray Observatory (blue), optical light obtained with the Hubble Space Telescope (gold) and radio waves from the NSF’s Very Large Array (pink).
This multi-wavelength view shows 4C+29.30, a galaxy located some 850 million light years from Earth. The radio emission comes from two jets of particles that are speeding at millions of miles per hour away from a supermassive black hole at the center of the galaxy. The estimated mass of the black hole is about 100 million times the mass of our Sun. The ends of the jets show larger areas of radio emission located outside the galaxy.
The X-ray data show a different aspect of this galaxy, tracing the location of hot gas. The bright X-rays in the center of the image mark a pool of million-degree gas around the black hole. Some of this material may eventually be consumed by the black hole, and the magnetized, whirlpool of gas near the black hole could in turn, trigger more output to the radio jet.
Most of the low-energy X-rays from the vicinity of the black hole are absorbed by dust and gas, probably in the shape of a giant doughnut around the black hole. This doughnut, or torus blocks all the optical light produced near the black hole, so astronomers refer to this type of source as a hidden or buried black hole. The optical light seen in the image is from the stars in the galaxy.
Venus Transit 2012 from Guatemala — Sergio Montúfar
Polygons are of great interest because they often indicate the presence of shallow ice or of desiccation such as in a mud flat. However, nature sometimes seems too clever for us.
Polygons form by the intersecting ridges of sand dunes. If this deposit were to become indurated and eroded, we might not be able to tell that they originated as wind-blown dunes, and interpret the polygons as evidence for a dried-up lake, for example. Dunes often accumulate in the bottoms on craters, also a good setting for a (temporary) lake.
The illumination is coming from the upper left, so the bluish ridges are high-standing.
