One of the first photos of the possible new supernova in the nearby galaxy M74 taken by the Italian Supernova Search Project. The object is located 93" east and 135" south of the galaxy's center. Click to learn more about the search group. Credit: Fabio Martinelli
I love this galaxy. Not only does M74display a near perfect spiral form but if this latest supernova is the third to “go boom” in the galaxy in just 11 years. The new object, designated PSN J01364816+1545310, was discovered blazing near 12.4 magnitude by the Lick Observatory Supernova Search at Lick Observatory near San Jose, Calif. “PSN” stands for “possible supernova” and the long string of numbers give the object’s position in the sky using the celestial equivalents of latitude and longitude.
Update: The supernova has now been confirmed, and is now officially named SN 2013ej.
Supernova 2013ej, taken remotely on July 29, 2013 from iTelescope Network using the Siding Spring Observatory. Credit: Ernesto Guido and Nick Howes/Remanzacco Observatory.
M74 is a classic spiral galaxy with arms that appear to unwind from a bright, star-packed nucleus. Located 32 million light years away in the constellation Pisces, M74 contains about 100 billion stars. The spiral arms are dotted with dense star clusters and pink clouds of fluorescing hydrogen gas. Credit: Jim Misti
The Lick search uses a fully robotic or automated 30-inch (76 cm) telescope dedicated to scanning the skies for new supernovae. It nailed M74’s latest exploding star on July 25. Two previous supernovae flared in the galaxy – SN 2002apand SN 2003gd– and rose to 12th and 13th magnitude respectively before fading away into obscurity.
Size comparison of our Milky Way spiral galaxy with M74. The Milky Way measures about 100,000 light years across; M74 about 30,000. Credit: NASA (left) and Jim Misti
Three’s the charm as they say. A team of astronomers using a spectrograph at the Faulkes Telescope South at Siding Spring, Australia teased apart the supernova’s light and now know exactly what blew up. It appears our newcomer was originally a supergiant star at least 8 times as massive as the sun. After a relatively brief lifetime measured in the millions of years, the supergiant gobbled up the last of its fuel. With the gas gauge on “empty” and no new energy being produced in the core to hold back the force of gravity, the star imploded, sending a shockwave rocketing back in the opposite direction that tore it to bits.
When a massive star runs out of nuclear fuel in its core, the energy that has prevented the force of gravity from crushing it is gone. Gravity finally gains the upper hand causing the star to implode. A rebounding shock wave blows it to bits. Sometime a city-sized, dense stellar remnant called a neutron star remains after the blast. Credit: ESO
Called a Type II supernova explosion, the blast hurtles star stuff into space at up to 45,000 miles per second (70,000 km/sec). More amazing, a powerful supernova explosion can release as much energy as the sun during its entire 10 billion year lifetime. No wonder even small telescopes can spot these cataclysmic events from millions of light years away!
The galaxy M74, the 74th entry in 18th century astronomer Charles Messier’s catalog, is found about 1.5 degrees east-northeast of the star Eta Piscium just to the right of the small constellation Aries the Ram. The map shows the sky around 1 a.m. tomorrow morning facing east. Stellarium
As additional photos and measurements come in, amateur astronomers with 8-inch and larger telescopes will have no problem spying the supernova once the last quarter moon departs the vicinity. It’s located 93″ (1.5′) east and 135″ (more than 2′) southeast of the galaxy’s core. The map and photo will help you track it down.
This map measures only about 1/2-degree wide and shows the galaxy up close with the supernova marked SN. Selected star magnitudes from the AAVSO are shown to help you navigate to the object as well as estimate its brightness. North is up, west to the right. Map created with Chris Marriott’s SkyMap software
While M74 is relatively bright and appears spectacular in long-exposure photos, it looks like a large, dim featureless glow in smaller telescopes. Be patient and take your time to “star hop” to the supernova using the more detailed map. Matter of fact, you may want to wait until Tuesday morning or later to look. That’s when the waning moon will finally depart the area. Let’s hope our new guest remains bright.
Good luck meeting the latest star to mark the end of its life with the biggest blowout of all. For more information and photos, stop by Dave Bishop’s Latest Supernovae site.
* This article was updated at 6:30 pm CDT on 7/28/13
The Southern Delta Aquarid radiant, looking southeast at 2AM local from latitude 30 degrees north on the morning of July 30th. (Created by the author in Starry Night).
The meteor shower drought ends this weekend.
The northern summer hemisphere meteor season is almost upon us. In a few weeks’ time, the Perseids — the “Old Faithful” of meteor showers — will be gracing night skies worldwide.
But the Perseids have an “opening act”- a meteor shower optimized for southern hemisphere skies known as the Delta Aquarids.
This year offers a mixed bag for this shower. The Delta Aquarids are expected to peak on July 30th and we should start seeing some action from this shower starting this weekend.
The Moon, however, also reaches Last Quarter phase the day before the expected peak of the Delta Aquarids this year on July 29th at 1:43PM EDT/17:43 Universal Time (UT). This will diminish the visibility of all but the brightest meteors in the early morning hours of July 30th.
A cluster of meteor shower radiants also lies nearby. The Eta Aquarids emanate from a point near the asterism known as the “Water Jar” in the constellation Aquarius around May 5th. Another nearby but weaker shower known as the Alpha Capricornids are also currently active, with a zenithal hourly rate (ZHR) approaching the average hourly sporadic rate of 5. And speaking of which, the antihelion point, another source of sporadic meteors, is nearby in late July as well in eastern Capricornus.
The Delta Aquarids are caused by remnants of Comet 96P/Machholz colliding with Earth’s atmosphere. The short period comet was only discovered in 1986 by amateur astronomer Donald Machholz. Prior to this, the source of the Delta Aquarids was a mystery.
The Delta Aquarids have a moderate atmospheric entry velocity (for a meteor shower, that is) around an average of 41 kilometres a second. They also have one of the lowest r values of a major shower at 3.2, meaning that they produce a disproportionately higher number of fainter meteors, although occasional brighter fireballs are also associated with this shower.
Image of an early confirmed Delta Aquarid by the UK Meteor Network (@UKMeteorNetwork on Twitter) captured by their Ash Vale North camera on July 17th, 2013. (Credit: Richard Kacerek & United Kingdom Meteor Observation Network, used with permission).
The Delta Aquarids are also one the very few showers with a southern hemisphere radiant. It’s somewhat of a mystery as to why meteor showers seem to favor the northern hemisphere. Of the 18 major annual meteor showers, only four occur below the ecliptic plane and three (the Alpha Capricornids, and the Eta and Delta Aquarids) approach the Earth from south of the equator. A statistical fluke, or just the product of the current epoch?
In fact, the Delta Aquarids have the most southern radiant of any major shower, with a radiant located just north of the bright star Fomalhaut in the constellation Piscis Austrinus near Right Ascension 339 degrees and Declination -17 degrees. Researchers have even broken this shower down into two distinct northern and southern radiants, although it’s the southern radiant that is the more active during the July season.
Together, this loose grouping of meteor shower radiants in the vicinity is known as the Aquarid-Capricornid complex. The Delta Aquarids are active from July 14th to August 18th, and unlike most showers, have a very broad peak. This is why you’ll see sites often quote the maximum for the shower at anywhere from July 28th to the 31st. In fact, you may just catch a stray Delta Aquarid while on vigil for the Perseids in a few weeks!
The shower was first identified by astronomer G.L. Tupman, who plotted 65 meteors associated with the stream in 1870. Observations of the Delta Aquarids were an off-and-on affair throughout the early 20th century, with many charts erroneously listing them as the “Beta Piscids”. The separate northern and southern radiants weren’t even untangled until 1950. The advent of radio astronomy made more refined observations of the Delta Aquarids possible. In 1949, Canadian astronomer D.W.R. McKinley based out of Ottawa, Canada identified both streams and pinned down the 41 km per second velocity that’s still quoted for the shower today.
Further radio studies of the shower were carried out at Jodrell Bank in the early 1950’s, and the shower gave strong returns in the early 1970’s for southern hemisphere observers even with the Moon above the horizon, with ZHRs approaching 40. The best return for the Southern Delta Aquarids in recent times is listed by the International Meteor Organization as a ZHR of about 40 on the morning of July 28th, 2009.
A study of the Delta Aquarids in 1963 by Fred Whipple and S.E. Hamid reveal striking similarities between the Delta Aquarids and the January Quadrantids & daytime Arietid stream active in June. They note that the orbital parameters of the streams were similar about 1,400 years ago, and the paths are thought to have diverged due to perturbations from the planet Jupiter.
Observing the Delta Aquarids can serve as a great “dry run” for the Perseids in a few weeks. You don’t need any specialized gear, simply find a dark site, block the Moon behind a building or hill, and watch.
Photographing meteors is similar to doing long exposures of star trails. Simply aim your tripod mounted DSLR camera at a section of sky and take a series of time exposures about 1-3 minutes long to reveal meteor streaks. Images of Delta Aquarids seem elusive, almost to the point of being mythical. An internet search turns up more blurry pictures of guys in ape suits purporting to be Bigfoot than Delta Aquarid images… perhaps we can document the “legendary Delta Aquarids” this year?
– Read more of the fascinating history of the Delta Aquarids here.
– Seen a meteor? Be sure to tweet it to #Meteorwatch.
“We will hand out our medals to all the athletes who will win gold on that day, because both the meteorite strike and the Olympic Games are the global events,” stated Chelyabinsk Region Culture Minister Alexei Betekhtin in a Ria Novosti report.
The reported sports that will receive these medals include:
Women’s 1,000 meter and men’s 1,500 meter short track;
Artist's concept of a GOES spacecraft in orbit. (Credit: NOAA.gov).
It’s sometimes tough being a satellite in Earth orbit these days.
An interesting commentary came our way recently via NASA’s Orbital Debris Program Office’s Orbital Debris Quarterly News. The article, entitled High-Speed Particle Impacts Suspected in Two Spacecraft Anomalies, highlights a growing trend in the local space environment.
The tale begins with GOES 13 located in geostationary orbit over longitude 75° West. Launched on May 24th, 2006 atop a Delta IV rocket, GOES 13 is an integral part of the U.S. National Oceanic and Atmospheric Administration (NOAA’s) Geostationary Operational Environmental Satellite network.
The problems began when GOES-13 began to suffer an “attitude disturbance of unknown origin” on May 22nd of this year, causing it to drift about two degrees per hour off of its required nadir (the opposite of zenith) pointing.
The anomaly was similar to a problem encountered by the NOAA 17 spacecraft on November 20th, 2005. At the time, the anomaly was suspected to be due to a micrometeoroid impact. The Leonid meteors, which peak right around the middle of November, were a chief suspect. However, NOAA 17 suffered a second failure 18 days later, which was later traced down to a hydrazine leak from its errant thrusters.
GOES-13 has weathered hard times before. Back in December of 2006, GOES-13’s Solar X-Ray Imager suffered damage after being struck by a solar flare shortly after initial deployment. GOES-13 also began returning degraded imagery in September 2012, forcing it into backup status for Hurricane Sandy.
GOES-13 was restored to functionality last month. Current thinking is that the satellite was struck by a micrometeorite. No major meteor showers were active at the time.
Loss of a GOES satellite would place a definite strain on our weather monitoring and Earth observing capability. Begun with the launch of GOES-1 in 1975, currently six GOES satellites are in operation, including one used to relay data for PeaceSat (GOES-7) and one used as a communications relay for the South Pole research station (GOES-3).
The GOES program cost NOAA billions in cost overruns to execute. The next GOES launch is GOES-R scheduled in 2015.
But the universe seems to love coincidences.
NEE-01 Pegaso before deployment. (Credit: Wikimedia Commons image in the Public Domain).
Less than 26 hours after the GOES 13 anomaly, Ecuador’s first satellite, NEE-01 Pegaso began to have difficulties keeping a stable attitude. The event happened shortly after passage near an old Soviet rocket booster (NORAD designation 1986-058B) which launched Kosmos 1768 on August 2nd, 1986. The U.S. Joint Space Operations Center had warned the fledgling Ecuadorian Space Agency that conjunction was imminent, but of course, there’s not much that could’ve been done to save the tiny CubeSat.
Although the main mass passed Pegaso at a safe distance, current thinking is that the discarded booster may have left a cloud of debris in its wake. Researchers have tracked small “debris clouds” around objects it orbit before- the collision of Iridium 33 and the defunct Kosmos 2251 on February 10th, 2009 left a ring of debris in its wake, and the Chinese anti-satellite test carried out on January 11th, 2007 showered low-Earth orbit with debris for years to come.
The loss represents a blow to Ecuador and their first bid to become a space-faring nation. Launched less than a month prior atop a Long March 2D rocket, Pegaso was a small 10 centimetre nanosatellite equipped with solar panels and dual infrared and visible Earth imaging systems.
A translation from the Ecuadorian Space Agencies site states that;
“The NEE-01 survived the crash and remains in orbit; however it has entered uncontrolled rotation due to the event.
Due to this rotation, (the satellite) cannot point its antenna correctly and stably to the Earth station and although still transmitting and running, the signal cannot be decoded. The Ecuadorian Civilian Space Agency is working tirelessly to stabilize the NEE-01 and recover the use of their signal.
The PEGASUS aired for 7 days your signal to the world via EarthCam, millions could see the Earth seen from space in real time, many for the first time, the files in those 7 days have been published after transmission.”
Ecuador plans to launch another CubeSat, NEE 02 Krysaor later in 2013. A carrier has not yet been named.
While both events suffered by the GOES-13 and NEE-01 Pegaso satellites were unrelated, they underscore problems with space junk and space environmental hazards that are occurring with a higher frequency.
Gabbard diagram displaying a sample disintegration of a Long March 4 booster in 2000. (Credit: the NASA Orbital Debris Office).
Such is the modern hazardous environment of low Earth orbit that new satellites must face. With a growing amount of debris, impact threats are becoming more common. The International Space Station must perform frequent debris avoidance maneuvers to avoid hazards, and more than once, the crew has waited out a pass in their Soyuz escape modules should immediate evacuation become necessary. Punctures from micro-meteoroids or space junk have even been seen recently on the ISS solar panel arrays.
Plans are on the drawing board to deal with space junk, involving everything from “space nets” to lasers and even more exotic ideas. Probably the most immediate solution that can be implemented is to assure new payloads have a way to “self-terminate” via de-orbit at the end of their life span. Solar sail technologies, such as NanoSailD2 launched in 2010 have already demonstrated this capability.
Expect reentries also pick up as we approach the peak of solar cycle #24 at the end of 2013 and the beginning of 2014. Increased solar activity energizes the upper atmosphere and creates increased drag on low Earth satellites.
It’s a brave new world “up there,” and hazards, both natural and man-made, are something that space faring nations will have to come to terms with.
-Read and subscribe to the latest edition of NASA’s Orbital Debris Quarterly News for free here.
The gibbous Moon rising rising over the Andes Mountains in Chile. (Credit: @WladimirPulgarG/Flickr).
“Once more into the breach, my dear friends…”
Such a quip may be deemed appropriate as we endured the media onslaught this past weekend for the third and final perigee Full Moon of 2013.
Tonight, on Monday, July 22nd, the Moon reaches Full at 18:15 Universal Time (UT)/4:15 PM EDT. This is only 21.9 hours after reaching perigee, or the closest point in its orbit at 358,401 kilometres from the Earth on the Sunday evening at 20:28 UT. Continue reading “Super-Moon Monday: The 3rd (& Final?) Act”
Painting of The Meteor of 1860 by Hudson River School artist Frederic Church. (Credit: Frederic Church courtesy of Judith Filenbaum Hernstadt).
“Year of meteors! Brooding year!”
-Walt Whitman
July 20th is a red letter date in space history. Apollo 11, the first crewed landing on the Moon, took place on this day in 1969. Viking 1 also made the first successful landing on Mars, seven years later to the day in 1976.
A remarkable astronomical event also occurred over the northeastern United States 153 years ago today on the night of July 20th, known as the Great Meteor Procession of 1860. And with it came a mystery of poetry, art and astronomy that was only recently solved in 2010.
A meteor procession occurs when an incoming meteor breaks up upon reentry into our atmosphere at an oblique angle. The result can be a spectacular display, leaving a brilliant glowing train in its wake. Unlike early morning meteors that are more frequent and run into the Earth head-on as it plows along in its orbit, evening meteors are rarer and have to approach the Earth from behind. In contrast, these often leave slow and stately trains as they move across the evening sky, struggling to keep up with the Earth.
The Great Meteor Procession of 1860 also became the key to unlock a 19th century puzzle as well. In 2010, researchers from Texas University San Marcos linked the event to the writings of one of the greatest American poets of the day.
Photograph of Walt Whitman taken by Mathew Brady circa 1860 (Library of Congress image in the Public Domain)..
Walt Whitman described a “strange, huge meteor-procession” in a poem entitled “Year of Meteors (1859-60)” published in his landmark work Leaves of Grass.
English professor Marilynn S. Olson and student Ava G. Pope teamed up with Texas state physics professors Russell Doescher & Donald Olsen to publish their findings in the July 2010 issue of Sky & Telescope.
As a seasoned observer, Whitman had touched on the astronomical in his writings before.
The event had previously been attributed over the years to the Great Leonid Storm of 1833, which a young Whitman would’ve witnessed as a teenager working in Brooklyn, New York as a printer’s apprentice.
Researchers noted, however, some problems with this assertion.
The stanza of contention reads;
Nor forget I sing of the wonder, the ship as she swam up my bay,
Well-shaped and stately, the Great Eastern swam up my bay, she was 600 feet long,
Her moving swiftly surrounded by myriads of small craft I forget not to sing;
Nor the comet that came unannounced out of the north flaring in heaven,
Nor the strange huge meteor-procession dazzling and clear shooting over our heads.
(A moment, a moment long, it sail’d its balls of earthly light over our heads,
Then departed, dropt in the night, and was gone.)
In the poem, the sage refers to the arrival of the Prince of Wales in New York City on October 1860. The election of Abraham Lincoln in November of that same year is also referred to earlier in the work. Whitman almost seems to be making a cosmic connection similar to Shakespeare’s along the lines of “When beggars die, no comets are seen…”
Path of the Meteor Procession of 1860 as depicted in the newspapers of the day. (From the collection of Don Olson).
The “comet that came unannounced” is easily identified as the Great Comet of 1860. Also referred to as Comet 1860 III, this comet was discovered on June 18th of that year and reached +1st magnitude that summer as it headed southward. The late 19th century was rife with “great comets,” and northern hemisphere observers could look forward to another great cometary showing on the very next year in 1861.
The Great Comet of 1861 as drawn by G. Williams on June 30th, 1861. (From Descriptive Astronomy by George Chambers, 1877)
There are some problems, however with the tenuous connection between the stanza and the Leonids.
The 1833 Leonids were one of the most phenomenal astronomical events ever witnessed, with estimates of thousands of meteors per second being seen up and down the U.S. Eastern Seaboard the morning of November 13th. Whitman himself described the event as producing;
“…myriads in all directions, some with long shining white trains, some falling over each other like falling water…”
Keep in mind, many startled townsfolk assumed their village was on fire on that terrifying morning in 1833, as Leonid bolides cast moving shadows into pre-dawn bedrooms. Churches filled up, as many thought that Judgment Day was nigh. The 1833 Leonids may have even played a factor in sparking many of the religious fundamentalist movements of the 1830s. We witnessed the 1998 Leonids from Kuwait, and can agree that this meteor shower can be a stunning sight at its peak.
But Whitman’s poem describes a singular event, a “meteor-procession” very different from a meteor shower.
Various sources have tried over the years to link the stanza to a return of the Leonids in 1858. A note from Whitman mentions a “meteor-shower, wondrous and dazzling (on the) 12th-13th, 11th month, year 58 of the States…” but keep in mind, “year 1” by this reckoning is 1776.
A lucky break came for researchers via the discovery of a painting by Frederic Church entitled “The Meteor of 1860.” This painting and several newspaper articles of the day, including an entry in the Harpers Weekly, collaborate a bright meteor procession seen across the northeastern U.S. from New York and Pennsylvania across to Wisconsin.
Such a bright meteor entered the atmosphere at a shallow angle, fragmented, and most likely skipped back out into space. Similar meteor processions have been observed over the years over the English Channel on August 18th, 1783 & across the U.S. Eastern Seaboard and Canada on February 9th, 1913.
On August 10th, 1972, a similar bright daylight fireball was recorded over the Grand Tetons in the western United States. Had the Great Meteor Procession of 1860 come in at a slightly sharper angle, it may have triggered a powerful airburst such as witnessed earlier this year over Chelyabinsk, Russia the day after Valentine’s Day.
The 1860 Meteor Procession is a great tale of art, astronomy, and mystery. Kudos to the team of researchers who sleuthed out this astronomical mystery… I wonder how many other unknown stories of historical astronomy are out there, waiting to be told?
This photo was taken on January 22, 2012 in Fairbanks North Star Borough County, Alaska, US, using a Nikon D5000. The explodey look is due to perspective from looking right up the magnetic field lines. The aurora in the middle of the explosion is pointing straight down at the camera. Credit: Jason Ahrns
A military program to investigate auroras in the north appears to have been suspended.
The High Frequency Active Auroral Research Program (HAARP)’s website (dead link here) is not available right now, and there’s been some media speculation about the program’s future. So far, though, our attempts to learn more about the situation have turned up little information.
When Universe Today reached out to Keeney, however, he declined comment. We also got in touch with the public affairs officials at Kirtland Air Force Base, who said no one was immediately available for an interview and provided this statement:
A screenshot of Google Earth, with ionosphere overlayed (Google)
“HAARP is currently in contract negotiations and our policy is not to comment on current contract negotiations,” stated Marie M. Vanover, the director of Kirtland public affairs. “HAARP’s website is expected to be reopened and populated with the new and current information within 2-3 weeks.”
The program is jointly managed by the U.S. Air Force Research Laboratory and the U.S. Naval Research Laboratory to investigate activity in the ionosphere, the region of the Earth’s atmosphere where auroras occur. It includes an array of dozens of antennas that, media reports say, energize parts of the ionosphere.
HAARP is also the target of many conspiracy theories, ranging from warnings that it would trigger a change in the Earth’s magnetic poles to accusations that it is actually a weapon prototype. You can read more about the unproven allegations in this 2009 Wired article.
We’ll keep you posted on the facility’s status as we hear more.
As NASA’s fiscal 2014 budget proceeds through Congress, it’s still quite the ping-pong ball match to try to figure out where their budget numbers will fall. How do you think the budget will end up? Leave your thoughts in the comments.
Also, be sure to watch the latest markup on the NASA bill occurring today when the House Committee on Science, Space and Technology meets — the webcast is here. It starts at 11:15 a.m. EDT/3:15 p.m. GMT.
– Obama administration initial request – $17.7 billion: Unveiled in early April, the $17.7 billion “tough choices” NASA budget was for $50 million less than requested in 2013; the actual FY 2013 budget was $16.6 billion due to cuts and sequestration. While reducing funding opportunities for planetary science, the FY 2014 budget provided funding for a NASA mission to capture an asteroid. The asteroid mission proposal, in later weeks, did not impress at least one subcommittee.
It appears that NASA’s proposed Space Launch System is getting budgetary support from at least some House members. Credit: NASA
– U.S. Senate Appropriations Subcommittee on Commerce, Justice, Science, and Related Agencies – $18 billion: On Tuesday, the Senate subcommittee suggested an allocation to NASA of $18 billion. A press release says the budget level will give “better balance for all of NASA’s important missions, including $373 million more for science that helps us to better understand Earth and own solar system while peering at new worlds way beyond the stars. The Senate also provides $597 million more to let humans explore beyond low earth orbit while safely sending our astronauts to the space station on U.S. made vehicles.”
– NASA’s reaction: David Weaver, NASA’s associate administrator for communications, said the agency is “deeply concerned” about the House funding levels. “While we appreciate the support of the Committee, we are deeply concerned that the bill under consideration would set our funding level significantly below the President’s request,” he wrote in a blog post, adding, “We are especially concerned the bill cuts funding for space technology – the “seed corn” that allows the nation to conduct ever more capable and affordable space missions – and the innovative and cost-effective commercial crew program, which will break our sole dependence on foreign partners to get to the Space Station. The bill will jeopardize the success of the commercial crew program and ensure that we continue to outsource jobs to Russia.”
– Reaction of Commercial Spaceflight Federation: Much the same as NASA. “Less funding for the commercial
NASA fears there will not be enough money to fund commercial providers such as SpaceX (Dragon cargo spacecraft pictured) who aim to bring astronauts to the space station themselves. Credit: NASA/CSA/Chris Hadfield
crew program simply equates to prolonged dependence on foreign launch providers,” stated federation president Michael Lopez-Alegria, who is a former NASA astronaut. “As a nation, we should be doing our utmost to regain the capability of putting astronauts in orbit on American vehicles as soon as possible.”
– What’s next: The House Committee on Science, Space and Technology markup of the NASA bill takes place starting at 11:15 a.m. EDT/3:15 p.m. GMT (again, watch the webcast at this link.) We’ll keep you posted on what they say. The Planetary Society’s Casey Dreier, who said $16.6 billion is the smallest NASA budget in terms of purchasing power since 1986, points out that the House doesn’t have the final say: “The Senate still needs to weigh in, so this House budget is not the last word in the matter, but it’s deeply troubling. You can’t turn NASA on and off like a spigot. Cuts now will echo through the coming decades.”
An artist's concept of a rocky world orbiting a red dwarf star. (Credit: NASA/D. Aguilar/Harvard-Smithsonian center for Astrophysics).
Hunters of alien life may have a new and unsuspected niche to scout out.
A recent paper submitted by Associate Professor of Astronomy at Columbia University Kristen Menou to the Astrophysical Journal suggests that tidally-locked planets in close orbits to M-class red dwarf stars may host a very unique hydrological cycle. And in some extreme cases, that cycle may cause a curious dichotomy, with ice collecting on the farside hemisphere of the world, leaving a parched sunward side. Life sprouting up in such conditions would be a challenge, experts say, but it is — enticingly — conceivable.
The possibility of life around red dwarf stars has tantalized researchers before. M-type dwarfs are only 0.075 to 0.6 times as massive as our Sun, and are much more common in the universe. The life span of these miserly stars can be measured in the trillions of years for the low end of the mass scale. For comparison, the Universe has only been around for 13.8 billion years. This is another plus in the game of giving biological life a chance to get underway. And while the habitable zone, or the “Goldilocks” region where water would remain liquid is closer in to a host star for a planet orbiting a red dwarf, it is also more extensive than what we inhabit in our own solar system.
Gliese 581- an example of a potential habitable zone around a red dwarf star contrasted with our own solar system. (Credit: ESO/Henrykus under a Wikimedia Creative Commons Attribution 3.0 Unported license).
But such a scenario isn’t without its drawbacks. Red dwarfs are turbulent stars, unleashing radiation storms that would render any nearby planets sterile for life as we know it.
But the model Professor Menou proposes paints a unique and compelling picture. While water on the permanent daytime side of a terrestrial-sized world tidally locked in orbit around an M-dwarf star would quickly evaporate, it would be transported by atmospheric convection and freeze out and accumulate on the permanent nighttime side. This ice would only slowly migrate back to the scorching daytime side and the process would continue.
Could these types of “water-locked worlds” be more common than our own?
The type of tidal locking referred to is the same as has occurred between the Earth and its Moon. The Moon keeps one face eternally turned towards the Earth, completing one revolution every 29.5 day synodic period. We also see this same phenomenon in the satellites for Jupiter and Saturn, and such behavior is most likely common in the realm of exoplanets closely orbiting their host stars.
The study used a dynamical model known as PlanetSimulator created at the University of Hamburg in Germany. The worlds modeled by the author suggest that planets with less than a quarter of the water present in the Earth’s oceans and subject to a similar insolation as Earth from its host star would eventually trap most of their water as ice on the planet’s night side.
Kepler data results suggest that planets in close orbits around M-dwarf stars may be relatively common. The author also notes that such an ice-trap on a water-deficient world orbiting an M-dwarf star would have a profound effect of the climate, dependent on the amount of volatiles available. This includes the possibility of impacts on the process of erosion, weathering, and CO2 cycling which are also crucial to life as we know it on Earth.
Thus far, there is yet to be a true “short list” of discovered exoplanets that may fit the bill. “Any planet in the habitable zone of an M-dwarf star is a potential water-trapped world, though probably not if we know the planet possesses a thick atmosphere.” Professor Menou told UniverseToday. “But as more such planets are discovered, there should be many more potential candidates.”
Hard times in harsh climes-an artist’s conception of the daytime side of a world orbiting a red dwarf star. (Credit: NASA/JPL-Caltech).
Being that red dwarf stars are relatively common, could this ice-trap scenario be widespread as well?
“In short, yes,” Professor Menou said to Universe Today. “It also depends on the frequency of planets around such stars (indications suggest it is high) and on the total amount of water at the surface of the planet, which some formation models suggest should indeed be small, which would make this scenario more likely/relevant. It could, in principle, be the norm rather than the exception, although it remains to be seen.”
Of course, life under such conditions would face the unique challenges. The daytime side of the world would be subject to the tempestuous whims of its red dwarf host sun in the form of frequent radiation storms. The cold nighttime side would offer some respite from this, but finding a reliable source of energy on the permanently shrouded night side of such as world would be difficult, perhaps relying on chemosynthesis instead of solar-powered photosynthesis.
On Earth, life situated near “black smokers” or volcanic vents deep on the ocean floor where the Sun never shines do just that. One could also perhaps imagine life that finds a niche in the twilight regions of such a world, feeding on the detritus that circulates by.
Some of the closest red dwarf stars to our own solar system include Promixa Centauri, Barnard’s Star and Luyten’s Flare Star. Barnard’s star has been the target of searches for exoplanets for over a century due to its high proper motion, which have so far turned up naught.
The closest M-dwarf star with exoplanets discovered thus far is Gliese 674, at 14.8 light years distant. The current tally of extrasolar worlds as per the Extrasolar Planet Encyclopedia stands at 919.
Searching for and identifying ice-trapped worlds may prove to be a challenge. Such planets would exhibit a contrast in albedo, or brightness from one hemisphere to the other, but we would always see the ice-covered nighttime side in darkness. Still, exoplanet-hunting scientists have been able to tease out an amazing amount of information from the data available before- perhaps we’ll soon know if such planetary oases exist far inside the “snowline” orbiting around red dwarf stars.
Read the paper on Water-Trapped Worlds at the following link.
New observations from ESO’s Very Large Telescope show for the first time a gas cloud being ripped apart by the supermassive black hole at the centre of the galaxy. Shown here are VLT observations from 2006, 2010 and 2013, coloured blue, green and red respectively. Credit: ESO/S. Gillessen
If you thought all was reasonably quiet at the center of the Milky Way, you’d be wrong. Of course, you knew there was a black hole waiting… but did you know the ESO’s Very Large Telescope has seen a cloud of gas being ripped apart by its influence? Thanks to new observations, we’re able to see – in real time – a gaseous region so stretched that its leading edge has reached the event horizon and it’s retreating from the black hole at more than 10 million km/h while the trailing end is still falling inward!
Just two years ago, the VLT observed a gas cloud several times the mass of Earth making haste towards the Milky Way’s central black hole… an oblivion which dwarfs the cloud by about a trillion times. Right now the plucky cloud has reached its closest approach and “spaghettification” has began. The vaporous vagabond is being stretched out of proportion by the black hole’s gravitational field.
“The gas at the head of the cloud is now stretched over more than 160 billion kilometres around the closest point of the orbit to the black hole. And the closest approach is only a bit more than 25 billion kilometres from the black hole itself — barely escaping falling right in,” explains Stefan Gillessen (Max Planck Institute for Extraterrestrial Physics, Garching, Germany) who led the observing team. “The cloud is so stretched that the close approach is not a single event but rather a process that extends over a period of at least one year.”
At this point, the gas cloud is becoming so thin that its light is difficult to detect. However, by using the SINFONI instrument on the VLT, researchers took 20 hours of exposure time with the integral field spectrometer and were able to measure the velocity of various regions of the gas cloud as it blazes by the black hole.
“The most exciting thing we now see in the new observations is the head of the cloud coming back towards us at more than 10 million km/h along the orbit — about 1% of the speed of light,” adds Reinhard Genzel, leader of the research group that has been studied this region for nearly twenty years. “This means that the front end of the cloud has already made its closest approach to the black hole.”
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Where the gas cloud originated is anyone’s guess – but there are suggestions. Possibilities include jets from the galactic center, or stellar winds from orbiting stars. There may have once been a star in the center of the cloud, and the gas may have been a product of its winds or even a protoplanetary disk. In any circumstance, these new observations help to sort out the variety of possibilities.
“Like an unfortunate astronaut in a science fiction film, we see that the cloud is now being stretched so much that it resembles spaghetti. This means that it probably doesn’t have a star in it,” concludes Gillessen. “At the moment we think that the gas probably came from the stars we see orbiting the black hole.”
It’s an exciting time to be an astronomer. Through the “eyes” of the VLT, researchers the world over are able to watch a very unique event as it happens and not after the fact. ” This intense observing campaign will provide a wealth of data, not only revealing more about the gas cloud, but also probing the regions close to the black hole that have not been previously studied and the effects of super-strong gravity.”
As this drama at the heart of the Milky Way unfolds, astronomers are able to witness its many changes – “from purely gravitational and tidal to complex, turbulent hydrodynamics.”
