THE GALAXY IN THE 'LOCAL VOID'

FROM:  NASA

Most galaxies are clumped together in groups or clusters. A neighboring galaxy is never far away. But this galaxy, known as NGC 6503, has found itself in a lonely position, at the edge of a strangely empty patch of space called the Local Void.

The Local Void is a huge stretch of space that is at least 150 million light-years across. It seems completely empty of stars or galaxies. The galaxy’s odd location on the edge of this never-land led stargazer Stephen James O’Meara to dub it the “Lost-In-Space galaxy” in his 2007 book, Hidden Treasures.

NGC 6503 is 18 million light-years away from us in the northern circumpolar constellation of Draco. NGC 6503 spans some 30,000 light-years, about a third of the size of the Milky Way.

This Hubble Space Telescope image shows NGC 6503 in striking detail and with a rich set of colors. Bright red patches of gas can be seen scattered through its swirling spiral arms, mixed with bright blue regions that contain newly forming stars. Dark brown dust lanes snake across the galaxy’s bright arms and center, giving it a mottled appearance.

The Hubble Advanced Camera for Surveys data for NGC 6503 were taken in April 2003, and the Wide Field Camera 3 data were taken in August 2013.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Photo Credit: NASA, ESA, D. Calzetti (University of Massachusetts), H. Ford (Johns Hopkins University), and the Hubble Heritage Team

THE DWARF GALAXY MARKARIAN 209

FROM:   NASA 

Caption Credit:  NASA.  This sprinkle of cosmic glitter is a blue compact dwarf galaxy known as Markarian 209. Galaxies of this type are blue-hued, compact in size, gas-rich, and low in heavy elements. They are often used by astronomers to study star formation, as their conditions are similar to those thought to exist in the early Universe. Markarian 209 in particular has been studied extensively. It is filled with diffuse gas and peppered with star-forming regions towards its core. This image captures it undergoing a particularly dramatic burst of star formation, visible as the lighter blue cloudy region towards the top right of the galaxy. This clump is filled with very young and hot newborn stars. This galaxy was initially thought to be a young galaxy undergoing its very first episode of star formation, but later research showed that Markarian 209 is actually very old, with an almost continuous history of forming new stars. It is thought to have never had a dormant period — a period during which no stars were formed — lasting longer than 100 million years. The dominant population of stars in Markarian 209 is still quite young, in stellar terms, with ages of under 3 million years. For comparison, the sun is some 4.6 billion years old, and is roughly halfway through its expected lifespan. The observations used to make this image were taken using Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys, and span the ultraviolet, visible, and infrared parts of the spectrum. A scattering of other bright galaxies can be seen across the frame, including the bright golden oval that could, due to a trick of perspective, be mistaken as part of Markarian 209 but is in fact a background galaxy. European Space Agency ESA/Hubble & NASA Acknowledgement: Nick Rose.

IN THE CONSTELLATION URSA MAJOR LIES NGC 2768

 
FROM: NASA

The soft glow in this image is NGC 2768, an elliptical galaxy located in the northern constellation of Ursa Major (The Great Bear). NGC 2768 appears here as a bright oval on the sky, surrounded by a wide, fuzzy cloud of material. This image, taken by the NASA/ESA Hubble Space Telescope, shows the dusty structure encircling the center of the galaxy, forming a knotted ring around the galaxy’s brightly glowing middle. Interestingly, this ring lies perpendicular to the plane of NGC 2768 itself, stretching up and out of the galaxy. The dust in NGC 2768 forms an intricate network of knots and filaments. In the center of the galaxy are two tiny, S-shaped symmetric jets. These two flows of material travel outwards from the galactic center along curved paths, and are masked by the tangle of dark dust lanes that spans the body of the galaxy. These jets are a sign of a very active center. NGC 2768 is an example of a Seyfert galaxy, an object with a supermassive black hole at its center. This speeds up and sucks in gas from the nearby space, creating a stream of material swirling inwards towards the black hole known as an accretion disk. This disk throws off material in very energetic outbursts, creating structures like the jets seen in the image above. Image Credit: NASA/ESA/Hubble

NASA VIEW OF THE HORSEHEAD NEBULA

FROM: NASA

Hubble Sees a Horsehead of a Different Color
Astronomers have used NASA's Hubble Space Telescope to photograph the iconic Horsehead Nebula in a new, infrared light to mark the 23rd anniversary of the famous observatory's launch aboard the space shuttle Discovery on April 24, 1990.

Looking like an apparition rising from whitecaps of interstellar foam, the iconic Horsehead Nebula has graced astronomy books ever since its discovery more than a century ago. The nebula is a favorite target for amateur and professional astronomers. It is shadowy in optical light. It appears transparent and ethereal when seen at infrared wavelengths. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that easily are visible in infrared light.

Hubble has been producing ground-breaking science for two decades. During that time, it has benefited from a slew of upgrades from space shuttle missions, including the 2009 addition of a new imaging workhorse, the high-resolution Wide Field Camera 3 that took the new portrait of the Horsehead. Image Credit-NASA-ESA-Hubble Heritage Team.

 

VIEW OF GALAXY NGC 1483

The excerpt and picture below are from the NASA website:
NASA's Hubble Space Telescope has produced this beautiful image of the galaxy NGC 1483. NGC 1483 is a barred spiral galaxy located in the southern constellation of Dorado — the dolphinfish (or Mahi-mahi fish) in Spanish. The nebulous galaxy features a bright central bulge and diffuse arms with distinct star-forming regions. In the background, many other distant galaxies can be seen. The constellation Dorado is home to the Dorado Group of galaxies, a loose group comprised of an estimated 70 galaxies and located some 62 million light-years away. The Dorado group is much larger than the Local Group that includes the Milky Way (and which contains around 30 galaxies) and approaches the size of a galaxy cluster. Galaxy clusters are the largest groupings of galaxies (and indeed the largest structures of any type) in the universe to be held together by their gravity. Barred spiral galaxies are so named because of the prominent bar-shaped structures found in their center. They form about two thirds of all spiral galaxies, including the Milky Way. Recent studies suggest that bars may be a common stage in the formation of spiral galaxies, and may indicate that a galaxy has reached full maturity. Image Credit: ESA/Hubble & NASA

STAR READIES FOR SPECTACULAR SUPERNOVA

“NASA's Hubble Telescope captured an image of Eta Carinae. This image consists of ultraviolet and visible light images from the High Resolution Channel of Hubble's Advanced Camera for Surveys. The field of view is approximately 30 arcseconds across. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star. Although 19th century astronomers did not have telescopes powerful enough to see the 1843 outburst in detail, its effects can be studied today. The huge clouds of matter thrown out a century and a half ago, known as the Homunculus Nebula, have been a regular target for Hubble since its launch in 1990. This image, taken with the Advanced Camera for Surveys High Resolution Channel, is the most detailed yet, and shows how the material from the star was not thrown out in a uniform manner, but forms a huge dumbbell shape. Eta Carinae is one of the closest stars to Earth that is likely to explode in a supernova in the relatively near future (though in astronomical timescales the "near future" could still be a million years away). When it does, expect an impressive view from Earth, far brighter still than its last outburst: SN 2006gy, the brightest supernova ever observed, came from a star of the same type, though from a galaxy over 200 million light-years away. Image Credit: ESA/NASA”

The above picture and following excerpt is from the NASA website:

HUBBLE TELESCOPE MAKES DISTANT SUPERNOVA DISCOVERY

                                                         Picture Courtesy NASA Website

“WASHINGTON -- NASA's Hubble Space Telescope has looked deep into the
distant universe and detected the feeble glow of a star that exploded
more than 9 billion years ago. The sighting is the first finding of
an ambitious survey that will help astronomers place better
constraints on the nature of dark energy, the mysterious repulsive
force that is causing the universe to fly apart ever faster.

"For decades, astronomers have harnessed the power of Hubble to
unravel the mysteries of the universe," said John Grunsfeld,
associate administrator for NASA’s Science Mission Directorate in
Washington. "This new observation builds upon the revolutionary
research using Hubble that won astronomers the 2011 Nobel Prize in
Physics, while bringing us a step closer to understanding the nature
of dark energy which drives the cosmic acceleration." As an
astronaut, Grunsfeld visited Hubble three times, performing a total
of eight spacewalks to service and upgrade the observatory.

The stellar explosion, nicknamed SN Primo, belongs to a special class
called Type Ia supernovae, which are bright beacons used as distance
markers for studying the expansion rate of the universe. Type Ia
supernovae likely arise when white dwarf stars, the burned-out cores
of normal stars, siphon too much material from their companion stars
and explode.

SN Primo is the farthest Type Ia supernova with its distance confirmed
through spectroscopic observations. In these types of observations, a
spectrum splits the light from a supernova into its constituent
colors. By analyzing those colors, astronomers can confirm its
distance by measuring how much the supernova's light has been
stretched, or red-shifted, into near-infrared wavelengths because of
the expansion of the universe.

The supernova was discovered as part of a three-year Hubble program to
survey faraway Type Ia supernovae, opening a new distance realm for
searching for this special class of stellar explosion. The remote
supernovae will help astronomers determine whether the exploding
stars remain dependable cosmic yardsticks across vast distances of
space in an epoch when the cosmos was only one-third its current age
of 13.7 billion years.

Called the CANDELS+CLASH Supernova Project, the census uses the
sharpness and versatility of Hubble's Wide Field Camera 3 (WFC3) to
assist astronomers in the search for supernovae in near-infrared
light and verify their distance with spectroscopy. CANDELS is the
Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and
CLASH is the Cluster Lensing and Supernova Survey.

"In our search for supernovae, we had gone as far as we could go in
optical light," said Adam Riess, the project's lead investigator, at
the Space Telescope Science Institute and The Johns Hopkins
University in Baltimore, Md. "But it's only the beginning of what we
can do in infrared light. This discovery demonstrates that we can use
the Wide Field Camera 3 to search for supernovae in the distant
universe."

The new results were presented on Jan. 11 at the American Astronomical
Society meeting in Austin, Texas.

The supernova team's search technique involved taking multiple
near-infrared images over several months, looking for a supernova's
faint glow. After the team spotted the stellar blast in October 2010,
they used WFC3's spectrometer to verify SN Primo's distance and to
decode its light, finding the unique signature of a Type Ia
supernova. The team then re-imaged SN Primo periodically for eight
months, measuring the slow dimming of its light.

By taking the census, the astronomers hope to determine the frequency
of Type Ia supernovae during the early universe and glean insights
into the mechanisms that detonated them.

"If we look into the early universe and measure a drop in the number
of supernovae, then it could be that it takes a long time to make a
Type Ia supernova," said team member Steve Rodney of The Johns
Hopkins University. "Like corn kernels in a pan waiting for the oil
to heat up, the stars haven't had enough time at that epoch to evolve
to the point of explosion. However, if supernovae form very quickly,
like microwave popcorn, then they will be immediately visible, and
we'll find many of them, even when the universe was very young. Each
supernova is unique, so it's possible that there are multiple ways to
make a supernova."

If astronomers discover that Type Ia supernovae begin to depart from
how they expect them to look, they might be able to gauge those
changes and make the measurements of dark energy more precise. Riess
and two other astronomers shared the 2011 Nobel Prize in Physics for
discovering dark energy 13 years ago, using Type Ia supernova to plot
the universe's expansion rate.

The Hubble Space Telescope is a project of international cooperation
between NASA and the European Space Agency. NASA's Goddard Space
Flight Center manages the telescope. The Space Telescope Science
Institute (STScI) conducts Hubble science operations. STScI is
operated for NASA by the Association of Universities for Research in
Astronomy, Inc., in Washington, D.C.”