Somethings from Astronomy

S/2004 N 1 - the smallest and newly discovered moon of Neptune

(This article has been cross-posted from SayPeople.com)

Main Point:

Astronomers discovered a tiny new moon, dubbed S/2004 N 1, around Neptune with the help of Hubble Space Telescope on July 1 and announced it on July 15.

Study Further:

Astronomers have reported that the new moon is the Neptune’s smallest moon of 14 of the known moons. It is just 12 miles (19 kilometers) wide. This moon is so small that it is about 100 million times fainter than the dimmest star.

"The moons and arcs [segments of rings around the planet] orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system," SETI Institute scientist Mark Showalter, the moon's discoverer, said in a statement. "It's the same reason a sports photographer tracks a running athlete — the athlete stays in focus, but the background blurs."

Scientists studied the photos taken by Hubble from the year 2004 to 2009 and found the moon in about 150 of those photos. They determined that the tiny moon orbits the Neptune about every 23 hours.

Source:

Space

First image of Pluto’s largest moon by NASA’s New Horizons spacecraft

(This article has been cross-posted from SayPeople.com)

This New Horizons LOng Range Reconnaissance Imager (LORRI) composite image shows the detection of Pluto’s largest moon, Charon, cleanly separated from Pluto itself. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Main Point:

NASA’s Pluto-bound New Horizons spacecraft took the first image of Charon, i.e. largest moon of the Pluto, with the help of highest-resolution telescopic camera.

Study Further:

Charon, discovered in 1978, is the largest moon of the Pluto’s five known moons. It is almost the size of Texas State of U.S. and is covered by ice. Charon is orbiting about 12,000 miles (more than 19,000 kilometers) away from Pluto.

The spacecraft was 550 million miles (885 million km) from Pluto, when its LOng Range Reconnaissance Imager (LORRI) snapped a total of six images: three July 1 and three more July 3.

“The image itself might not look very impressive to the untrained eye, but compared to the discovery images of Charon from Earth, these ‘discovery’ images from New Horizons look great!” said New Horizons Project Scientist Hal Weaver of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “We’re very excited to see Pluto and Charon as separate objects for the first time from New Horizons.”

“We’re excited to have our first pixel on Charon,” New Horizons Principal Investigator Alan Stern of the Southwest Research Institute said, “but two years from now, near closest approach, we’ll have almost a million pixels on Charon — and I expect we’ll be about a million times happier too!”

Source:

NewHorizons via Astronomy

Over 60 billion habitable planets probably present in our Milky Way

(This article has been cross-posted from SayPeople.com)

Over 60 billion habitable planets probably present in our Milky Way (Credit: mickare/deviantart)

Main Points:

Scientists have estimated that there could be over 60 billion habitable planets in our Milky Way alone. This estimate is about twice the previous estimates of at least one Earth-sized planet in the habitable zone of each red dwarf star.

Publishing in:

Astrophysical Journal Letters

Study Further:

Previous estimate was made by the researchers from Harvard University and this new thinking has been reported by the researchers from the University of Chicago and Northwestern University.

This new estimate has been made by considering “cloud cover”. Cloud cover is the concept given to the dayside of the exoplanets that are tidally locked i.e. one hemisphere of the planet continually faces the star (dayside), while the other faces away (darkside). It was thought that dayside would have high level of stellar flux but recent computer simulations showed otherwise due to the presence of clouds.

Cloud cover could be the reason that “tidally locked planets have low enough surface temperatures to be habitable,” explained Jang in his recently published paper.

Red dwarfs “represent about ¾ of the stars in the galaxy, so it applies to a huge number of planets,” Dr. Abbot, co-author on the paper, told Universe Today.

Future observations will approve or disprove this finding by measuring the cloud temperatures and James Webb Space Telescope would be one of the better options to study.

Source:

Universe Today

Reference:

Jun Yang, Nicolas B. Cowan, & Dorian S. Abbot (2013). Stabilizing Cloud Feedback Dramatically Expands the Habitable Zone of Tidally Locked Planets ApJ Letters, 771, L 45, 2013 arXiv: 1307.0515v

Huge amount of cold molecules and dust in the remnant of Supernova 1987A

(This article has been cross-posted from SayPeople.com)

Hubble Space Telescope image of supernova 1987A. The keyhole-like shape at the center is the remnant of supernova explosion 1987A. This remnant is still expanding. It is believed that the surrounding ring was formed before the explosion. // ESA/NASA/P. Challis and R. Kirshner

Main Point:

Astronomers have found a huge amount of cold molecules and dust grains in the supernova remnant - Supernova 1987A that surprised them.

Study Further:

Supernova 1987A was reported after an explosion of a massive star in the year 1987. That star was found in the nearby galaxy, the Large Magellanic Cloud located about 170,000 light-years away. According to astronomers, the supernova released about thousand million times more energy than the energy emitted by the Sun in one year.

Recently, astronomers used the Herschel Space Observatory and Atacama Large Millimeter/Submillimeter Array (ALMA) to study the supernova remnant and found huge amount of cold molecules and dust.

"The powerful explosion we saw in 1987 scattered elements made by the star into space in the form of a very hot plasma,” Mikako Matsuura from University College London, said in a statement. “The gas has now cooled down to temperatures between –250° to –170° Celsius [–420° to –275° Fahrenheit]. That's surprisingly cold, comparable to the icy surface of Pluto at the edge of our solar system. The gas has formed molecules and some have even condensed into solid grains of dust. The supernova has now become a super freezer!"

According to the observations, dust and solid material produced by the supernova was about 250,000 times the mass of Earth, or three-quarters of the mass of the Sun.

"We were surprised by the amount of dust and molecular gas in the reservoir created by the Supernova 1987A,” said Matsuura. “The ALMA and Herschel observations show that the reservoir contains carbon monoxide molecules equaling one-tenth the mass of the Sun. Herschel shows that the dust mass was even larger — about half the solar mass!"

"We don't get many opportunities to study supernovae. These events are very rare and the majority was found in very distant galaxies,” said Matsuura. “Even with relatively close ones, like 1987A, it's difficult. Although they are very bright at the time of the explosion, the light from the supernovae fades very quickly making it very difficult to observe them a few years after the explosion. Carl Sagan once said that: 'We are all made of star-stuff.' These results will help us understand how that material reached us!"  

Source:

Astronomy

"Great Eruption" of Eta Carinae would be resolved soon

Researchers have found the effects of "Great Eruption" of Eta Carinae, a supermassive star 7500 light years away, through mix of visible-light and spectroscopic observations.

Researchers have found that the star was cooler than it was previously suggested.

"When the eruption was seen on Earth 170 years ago, there were no cameras capable of recording the event," explained Armin Rest, who is leading researcher. "Everything astronomers have known to date about Eta Carinae's outburst is from eyewitness accounts. Modern observations with science instruments were made years after the eruption actually happened. It's as if nature has left behind a surveillance tape of the event, which we are now just beginning to watch. We can trace it year by year to see how the outburst changed."

Further Reading:
SayPeople

Galaxies eat each other

Researchers have pictured with the help of Jay GaBany's 0.5 m telescope at Black Bird Observatory and Saturn Lodge 0.7m telescope on the grounds of the Polaris Observatory Association first image of the two dwarf galaxies in which one dwarf galaxy, NGC 4449, is thought to engulf the other even smaller dwarf galaxy.

The dwarf galaxy NGC 4449 (top left) and the even tinier galaxy it is about to gobble up (bottom right).(Credit: R. Jay GaBany (Blackbird Observatory) in collaboration with David Martínez-Delgado (MPIA))

This research has been published online in the February 9 issue of the journal Nature.

Further Reading:
Saypeople

Very much clear Carina Nebula

European Southern Observatory has released very much clear picture of Carina Nebula i.e. massive star formation. Carina Nebula is located 7500 light years away from Earth.

You can see the picture below.

Carina Nebula (Credit: T. Preibisch/ESO)

In the center of the image, bright star is Trumpler 14. In the center at the right side, black dots with dark tails contain newly-forming stars.


At the bottom left corner, glowing light shows Eta Carinae i.e. an unstable star expected to explode soon with a supernova.


Further Reading:
SayPeople