Happy PI Day!
Want to see PI to a million digits? PI Day has it.by
Scientists using the W.M. Keck Observatory and Pan-STARRS1 telescopes have discovered a star that breaks a speed record. This star is traveling at 1,200 km/sec (2.7 million miles per hour). Fast enough so the star will escape the gravity of the galaxy and leave. Only a handful of such stars are known.
This star was part of a binary star system and was ejected by a supernova explosion. The image above is an artist impression and it shows the star to the left and the supernova at the same time but the supernova would have faded away by the time the star hit that position.
The hypervelocity stars are destined to spend their lives speeding through intergalactic space although it is thought usually such stars get ejected due to a close encounter with the black hole at the center of Milky Way.
While the image shown here is an artist concept, scientists observed this star called US 708 with the Echellette Spectrograph and Imager instrument on the 10-meter, Keck II telescope to measure its distance and velocity along our line of sight. By combining position measurements from the archives with new measurements from Pan-STARRS1, scientists were able to come up with the star’s velocity across our line of sight. The trajectory of the star shows the velocity cannot be from an encounter with a black hole.
There’s more (from the Keck press release):
US 708 has another peculiar property in marked contrast to other hypervelocity stars: it is a rapidly rotating, compact helium star likely formed by interaction with a close companion. Thus, US 708 could have originally resided in an ultra compact binary system, transferring helium to a massive white dwarf companion, ultimately triggering a thermonuclear explosion of a type Ia supernova. In this scenario, the surviving companion, i.e. US 708, was violently ejected from the disrupted binary as a result, and is now traveling with extreme velocity.
Plumes of unknown origin over Mars have been photographed. The plumes seen in in images taken March and April of 2012. The images prompted a review of Hubble images of Mars and sure enough an image was found from 17 May 1997.
These are not the clouds occasionally imaged at about 100 km in the atmosphere, this phenomenon is seen at 250 km.
“At about 250 km, the division between the atmosphere and outer space is very thin, so the reported plumes are extremely unexpected,” says Agustin Sanchez-Lavega of the Universidad del País Vasco in Spain, lead author of the paper reporting the results in the journal Nature.
Wow! Look at that! Click the image for the larger version and take it in.
You can see the zoomable version at Hubblesite.
NASA’s Hubble Space Telescope has revisited the famous Pillars of Creation, revealing a sharper and wider view of the structures in this visible-light image.
Astronomers combined several Hubble exposures to assemble the wider view. The towering pillars are about 5 light-years tall. The dark, finger-like feature at bottom right may be a smaller version of the giant pillars. The new image was taken with Hubble’s versatile and sharp-eyed Wide Field Camera 3.
The pillars are bathed in the blistering ultraviolet light from a grouping of young, massive stars located off the top of the image. Streamers of gas can be seen bleeding off the pillars as the intense radiation heats and evaporates it into space. Denser regions of the pillars are shadowing material beneath them from the powerful radiation. Stars are being born deep inside the pillars, which are made of cold hydrogen gas laced with dust. The pillars are part of a small region of the Eagle Nebula, a vast star-forming region 6,500 light-years from Earth.
The colors in the image highlight emission from several chemical elements. Oxygen emission is blue, sulfur is orange, and hydrogen and nitrogen are green.
This really isn’t astronomy but I really liked the video. Must have been a sight to see!
The five test and development A350-900s took to the skies for a formation flight in September 2014, bringing together all of the aircraft used for Airbus’ successful campaign leading to certification of this latest Airbus widebody jetliner.
The Voyager 1 spacecraft is still returning science data. When the Sun lets off a Coronal Mass Ejection or CME that wave moves outward. It can be responsible for auroral displays on Earth and even Jupiter and Saturn. The waves or what are termed “tsunami waves” go into interstellar space. The Voyager 1 spacecraft recently experienced three such waves beginning in February 2014. The video is a sound depiction of ionized matter interacting with the CME and “ring like a bell”.by
A TED Talk. It isn’t the solstice video I was intending to put up, but I liked it better.
Yes it’s a solstice day!
The December solstice is here. The solstice occurs in a few hours at 23:03 UTC. The calendar day would be 21 or 22 December depending on your location.
For me, it is the shortest day of the year and after a short pause the day’s light will slowly lengthen. The road to spring is long and as a well known old-time weather man around here used to say: “As the days grow longer the cold grows stronger”.
My favorite site for solstice information can be found at timeanddate.com.by