Sci-Fi Book Review: “Pilot” by R.D. Drabble

Pilot,” a new sci-fi thriller, follows law enforcement officer Legitt Redd, as he finds himself in the middle of an extraordinary set of circumstances. It is set in a solar system where humans occupy 6 life-supporting planets. Each planet has a different role to the civilisation, one being an energy source, another a prison, another a holiday destination, for example. Legitt is a low ranking officer whom serves for the oppressive government, ‘The Ministry.’ He is introduced as a fairly ordinary, uninspired man whose main duty is to transport prisoners to and from the Prison planet Gorby for processing. He has a long standing friendship and affiliation with one such prisoner – Afyd Geller whom has a reputation as a leader in the underworld and has the respect of many amongst law enforcement. Once a free man, Afyd often invites Leggit for drinking sessions. It‘s on one of these ordinary drinking sessions that the out-of-the-ordinary sequence of events begins. After a few adventure and violent encounters, they travel to the Litton where the apparent real figure head of the underworld resides. Leggit find out that the mythical ‘boogie man’ of child stories of old, Murlon Furlong is in fact a real person, and the all-powerful ruler of criminals.

Murlon sets Leggit, Afyd and other members of this motley crew, on a task to kidnap a spiritual leader. There is a back story of the civilisation’s theology which, in short includes the beginning of time and the eventual coming of salvation.

When this goes horribly wrong Legitt realises his true potential, and attempts to conquer Murlon and avoid swift and violent punishment of The Ministry. This means a whole lot more than he realises and intends the reader to question what is good and what is evil.

This book has great potential. Author R.D. Drabble paints pictures with his words, as if he can see them all around him. Initially this was inspiring to read. You can really imagine the frames in which Drabble was describing. But this positive is also a negative and too much visual description means at times it reads like a script, rather than a novel. There is only the present tense and only one story line, which leaves the reader feeling a bit flat with this one dimensional presentation of an otherwise interesting plot. It would have been a lot more enjoyable if there was a sub-plot or scenes that did not include the main character. Even though Leggit was in every scene, I still felt I didn’t have much insight into him as a character.

Having said that, there are definitely great moments. The technological creations and concepts found in Pilot are really inspiring. They seem to mix the spiritual human elements with technological fantasy. And the Drabble paints an Orwell-esque picture of the Ministry ruled worlds, and there were some phrases that were so poignant and poetic, that is will make you read them twice. The book starts of in a very certain black and white view of the world but progresses a grey outlook, at the same time that character Legitt questions his own morality in certain situations.

But these great moments are sandwiched between cliché, yet lovable characters and the many un-foreshadowed random unnecessary scenarios. There is an appendix of illustrations to support the story lines and backstories, but these don’t really add value or are explored.

Having said that it is clear that Drabble has an amazing amount of imagination. The 6 worlds and their stories are quiet intricate and to be honest, could be explored further in future books. I hope Drabble can express this obvious talent of imagination in future stories, especially if they are in comic or graphic novel format.

Overall, it’s a great read with some cool concepts.

R.D. Drabble is an electrician and science fiction fanatic who has had a lifelong obsession with the strange and inexplicable. It was his love for the unusual that inspired him to write his debut novel Pilot.

Pilot is available on Amazon.com and Lulu.com

Success! Progress Spacecraft Overcomes Stuck Antenna, Arrives at Station

Progress 51 on final approach to the International Space Station. The stuck antenna is visible below the crosshairs. Credit: NASA TV (screencap)

A software fix solved a sticky antenna problem on an unmanned cargo ship, a problem that threatened to interfere with the approach and docking to the International Space Station Friday.

Progress 51 successfully docked with the massive orbiting complex at 8:35 a.m. EDT (12:35 p.m. GMT) Friday without the need of assistance from the station crew, which was standing by to take over the docking just in case.

“Progress is safely docked! Big moment for the crew. Hooray!” wrote astronaut Chris Hadfield, the commander of Expedition 35, on Twitter moments after the spacecraft and station docked.

Watch all the action in the video, below:

Crew members are expected to start unloading the three tons of food, fuel, supplies and experiment on board later today (Friday), if all goes according to schedule.

The Russian supply ship has five antennas on board that are used for approaching the station for a docking using the KURS automated system. One of them refused to unfurl as usual after the spacecraft launched from the Baikonur Cosmodrome in Kazakhstan on Wednesday (April 24).

As a backup, crew members could bring the spacecraft in using a manual system that also allows them to view the station from a camera inside Progress.

The International Space Station as seen through the eyes of Progress 51. Credit: NASA TV (screencap)
The International Space Station as seen through the eyes of Progress 51. Credit: NASA TV (screencap)

This particular antenna, NASA said, is normally used to help keep the vehicle properly oriented as it gets closer to the station.

When the Progress spacecraft and station are 65 feet (20 meters) apart, the antenna also provides data on the relative roll of the vehicle with respect to the station.

NASA initially told the crew it was expected to bring the spacecraft in manually. Shortly after 6 a.m. EDT (10 a.m. GMT), however, capsule communicator David Saint-Jacques radioed that NASA was confident a software patch created by Russian ground controllers would address the problem.

Progress 51’s final approach proceeded normally, but controllers took it a little slower than usual to ensure the automated system was working properly with the  fix. The approach started slightly early, allowing capture to occur at 8:25 a.m. EDT (12:25 p.m. GMT) — two minutes earlier than planned.

Ground control and the Expedition 35 crew then spent several minutes verifying that the antenna would not interfere with the docking port. With crew members saying they couldn’t hear any funny noises from inside the station, NASA went forward with the hard docking.

Follow updates from Expedition 35 at Universe Today, and live on NASA’s television channel online.

Astrophotographers Capture “Mini” Lunar Eclipse

The brief partial lunar eclipse on Ari 25, 2013 captured over Israel. Credit and copyright: Gadi Eidelheit.

The lunar eclipse on April 25 was described by astrophotographer Gadi Eidelheit as “the greatest, slightest eclipse I ever saw!” The brief and small eclipse saw just 1.47% of the lunar limb nicked by the dark umbra or shadow from the Earth. It was visible from eastern Europe and Africa across the Middle East eastward to southeast Asia and western Australia. Here are a few more shots, including a serendipitous shot of an airplane flying through the eclipse!

Airliner flies through partial eclipse! On April 25, 2013, around 10:10 PM local time, the partial Lunar eclipse was at its maximum. The Moon only traveled 1,3% into the central Earth shadow (umbra). The event was visible from Europe, Asia and Australia. Canon EOS 600D on 130 mm (f/7,1) triplet Apo-refractor settings: 1/200 exposure at ISO 100.  Credit and copyright:  Philip Corneille – FRAS (Belgium).
Airliner flies through partial eclipse! On April 25, 2013, around 10:10 PM local time, the partial Lunar eclipse was at its maximum. The Moon only traveled 1,3% into the central Earth shadow (umbra). The event was visible from Europe, Asia and Australia. Canon EOS 600D on 130 mm (f/7,1) triplet Apo-refractor settings: 1/200 exposure at ISO 100. Credit and copyright: Philip Corneille – FRAS (Belgium).
The small, shallow eclipse on April 25, 2013. Credit and copyright: Andrei Juravle.
The small, shallow eclipse on April 25, 2013. Credit and copyright: Andrei Juravle.
Partially eclipsed Moon rising over Brixton in the UK on April 25, 2013. Credit and copyright: Owen Llewellyn.
Partially eclipsed Moon rising over Brixton in the UK on April 25, 2013. Credit and copyright: Owen Llewellyn.
Eclipsed Moon on April 25, 2013 over the UK. Credit and copyright: Sculptor Lil on Flickr.
Eclipsed Moon on April 25, 2013 over the UK. Credit and copyright: Sculptor Lil on Flickr.
The eclipsed Moon, with Saturn showing as a bright point of light on the left, as seen over Königswinter, Germany. Credit and copyright: Daniel Fischer.
The eclipsed Moon, with Saturn showing as a bright point of light on the left, as seen over Königswinter, Germany. Credit and copyright: Daniel Fischer.
The mini lunar eclipse on April 25, 2013 as seen from Bruges, Belgium. Credit and copyright: Cochuyt Joeri.
The mini lunar eclipse on April 25, 2013 as seen from Bruges, Belgium. Credit and copyright: Cochuyt Joeri.
A 'before' and 'during' comparison picture of the partial lunar eclipse on the 25th of April 2013. The photo on the left ('before') was taken at about 20h00 CAT and the photo on the right ('during') was taken around 22h06 CAT. Credit and copyright: Hein Oosthuyzen, Johannesburg, South Africa.
A ‘before’ and ‘during’ comparison picture of the partial lunar eclipse on the 25th of April 2013. The photo on the left (‘before’) was taken at about 20h00 CAT and the photo on the right (‘during’) was taken around 22h06 CAT. Credit and copyright: Hein Oosthuyzen, Johannesburg, South Africa.
Partial Lunar Eclipse on April 25, 2013. Credit and copyright: Henna Khan.
Partial Lunar Eclipse on April 25, 2013. Credit and copyright: Henna Khan.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

This Spot on Mercury (Almost) Never Goes Dark

A close "peak of eternal light" (PEL) near Mercury's south pole

Mercury, traveling in its 88-day-long orbit around the Sun with basically zero axial tilt, has many craters at its poles whose insides literally never see the light of day. These permanently-shadowed locations have been found by the MESSENGER mission to harbor considerable deposits of ice (a seemingly ironic discovery on a planet two-and-a-half times closer to the Sun than we are!*)

But if there are places on Mercury where the Sun never shines (insert butt joke here) then there may also be places where it always does. That’s what researchers are looking for in illumination maps made from MESSENGER data… and they’re getting closer.

The image above shows a region near Mercury’s south pole. The yellow arrow points to the closest thing to a true “peak of eternal light” found thus far on Mercury, a point that receives sunlight about 82% of the time — almost constantly illuminated.

From the JHUAPL MESSENGER mission site:

Studies of the illumination conditions near the north and south poles of Mercury are of interest because they can be used to determine locations of permanent shadow, extremely cold places where ice deposits lurk. However, the illumination maps also reveal the locations that receive the maximum duration of sunlight during a Mercury solar day.

A “peak of eternal light” that is illuminated continuously for an entire solar day would be a favorable target for a lander, because solar power would be available all the time. So far, no such peak of eternal light has been identified at Mercury’s south pole.

The spot that get the most illumination (about 82%), is located at 89° S, 50.7° E.

This image was acquired as part of MDIS’s campaign to monitor the south polar region of Mercury. By imaging the polar region approximately every four MESSENGER orbits as illumination conditions change, features that were in shadow on earlier orbits can be discerned and any permanently shadowed areas can be identified after repeated imaging over one solar day.

Illumination map of Mercury's south polar region (Pub. March 2012)
Illumination map of Mercury’s south polar region (Pub. March 2012)

“A ‘peak of eternal light’ that is illuminated continuously for an entire solar day would be a favorable target for a lander, because solar power would be available all the time.”

The top image above was acquired on Dec. 24, 2011. The large crater is Chao Meng-Fu, about 129 km (80 mi.) in diameter. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

*Without an atmosphere to hold and distribute heat, any place on Mercury that stays in shadow for any length of time will remain very cold — plenty cold enough for water ice to remain rock-hard indefinitely.

Giveaway: Luminos App For Your iOS Device

Have you ever wondered what it would be like to stand on the surface of Mars, or stare up at one of Saturn’s rings from the mountains of Titan? The Luminos App by Wobbleworks affords you the opportunity to give your friends a guided tour of the universe from the convenience of your iOS device. You can examine deep space objects, track satellites and fast forward or reverse time to understand the orbit of planets around the sun. If disaster movies don’t scare your pants off, you can view Near Earth Asteroids to see how many near misses the Earth has every year!

Wobbleworks provides an excellent user guide to this app complete with pictures and tutorials on how to create your own Observation Lists, log the date and time that a celestial body was viewed and keep track of satellites. It is really quite interesting to note the pass of the International Space Station.

Wobbleworks and Universe Today are giving away 10 free copies of Luminos!

This Giveaway is Now Closed

This giveaway will run for a week starting today, so get your entries in! How?

In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Thursday, May 2, 2013. We’ll send you a confirmation email, so you’ll need to click that to be entered into the drawing.

Words from Brian Albers – Luminos Developer:Luminos 1

Luminos, Astronomy for iOS, combines powerful features like telescope mount control, satellite tracking, and a five thousand year eclipse catalog with fun activities such as landing on remote bodies and tracking orbits in accelerated time. The Luminos data set includes two and a half million stars, tens of thousands of small bodies, up-to-date planet and moon surface features, and more. The design of the app emphasizes highly-tuned performance, with detailed models and an interface designed to maximize your view of the sky.
Luminos includes built-in help and online video tutorials, and keeps a frequent update schedule with new features introduced regularly. More information is at http://wobbleworks.com

Cassini Watches as Meteors Hit Saturn’s Rings

ive images of Saturn's rings, taken by NASA's Cassini spacecraft between 2009 and 2012, show clouds of material ejected from impacts of small objects into the rings. Image Credit: NASA/JPL-Caltech/Space Science Institute/Cornell.

From tell-tale evidence, we know that Earth, our Moon and other bodies in our Solar System are constantly barraged with both small meteoroids and larger asteroids or comets. And sometimes – like in the case of seeing meteors fling across our sky, or flashes on the Moon or Jupiter getting hit by Comet Shoemaker-Levy 9 — we even get to watch as it happens. Now, for the first time the Cassini spacecraft has provided direct evidence of small meteoroids crashing into Saturn’s rings.

Researchers say that studying the impact rate of meteoroids from outside the Saturnian system helps scientists understand how different planet systems in our solar system formed.

Saturn’s rings act as very effective detectors of many kinds of surrounding phenomena, including the interior structure of the planet and the orbits of its moons. For example, a subtle but extensive corrugation that ripples 12,000 miles (19,000 kilometers) across the innermost rings tells of a very large meteoroid impact in 1983.

“These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth — two very different neighborhoods in our solar system — and this is exciting to see,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It took Saturn’s rings acting like a giant meteoroid detector — 100 times the surface area of the Earth — and Cassini’s long-term tour of the Saturn system to address this question.”

The Saturnian equinox in summer 2009 was an especially good time to see the debris left by meteoroid impacts. The very shallow sun angle on the rings caused the clouds of debris to look bright against the darkened rings in pictures from Cassini’s imaging science subsystem.

This animation depicts the shearing of an initially circular cloud of debris as a result of the particles in the cloud having differing orbital speeds around Saturn. Image credit: NASA/Cornell

“We knew these little impacts were constantly occurring, but we didn’t know how big or how frequent they might be, and we didn’t necessarily expect them to take the form of spectacular shearing clouds,” said Matt Tiscareno, lead author of the paper and a Cassini participating scientist at Cornell University in Ithaca, N.Y. “The sunlight shining edge-on to the rings at the Saturnian equinox acted like an anti-cloaking device, so these usually invisible features became plain to see.”

Tiscareno and his colleagues now think meteoroids of this size probably break up on a first encounter with the rings, creating smaller, slower pieces that then enter into orbit around Saturn. The impact into the rings of these secondary meteoroid bits kicks up the clouds. The tiny particles forming these clouds have a range of orbital speeds around Saturn. The clouds they form soon are pulled into diagonal, extended bright streaks.

“Saturn’s rings are unusually bright and clean, leading some to suggest that the rings are actually much younger than Saturn,” said Jeff Cuzzi, a co-author of the paper and a Cassini interdisciplinary scientist specializing in planetary rings and dust at NASA’s Ames Research Center in Moffett Field, Calif. “To assess this dramatic claim, we must know more about the rate at which outside material is bombarding the rings. This latest analysis helps fill in that story with detection of impactors of a size that we weren’t previously able to detect directly.”

Source: JPL

Einstein Right Again! Rapidly Spinning Pulsar Follows General Relativity

This artist’s impression shows the exotic double object that consists of a tiny, but very heavy neutron star that spins 25 times each second, orbited every two and a half hours by a white dwarf star. The neutron star is a pulsar named PSR J0348+0432 that is giving off radio waves that can be picked up on Earth by radio telescopes. Although this unusual pair is very interesting in its own right, it is also a unique laboratory for testing the limits of physical theories. This system is radiating gravitational radiation, ripples in spacetime. Although these waves (shown as the grid in this picture) cannot be yet detected directly by astronomers on Earth they can be sensed indirectly by measuring the change in the orbit of the system as it loses energy. As the pulsar is so small the relative sizes of the two objects are not drawn to scale.

A unique and exotic laboratory about 6,800 light-years from Earth is helping Earth-based astronomers test Albert Einstein’s theory of general relativity in ways not possible until now. And the observations exactly match predictions from general relativity, say scientists in a paper to be published in the April 26 issue of the journal Science.

Using ESO’s Very Large Telescope along with other radio telescopes, John Antoniadis, a PhD student at the Max Planck Institute for radio Astronomy (MPIfR) in Bonn and lead author of the paper, says the bizarre pair of stars makes for an excellent test case for physics.

“I was observing the system with ESO’s Very Large Telescope, looking for changes in the light emitted from the white dwarf caused by its motion around the pulsar,” says Antoniadis. “A quick on-the-spot analysis made me realize that the pulsar was quite a heavyweight. It is twice the mass of the Sun, making it the most massive neutron star that we know of and also an excellent laboratory for fundamental physics.”

The strange pair consists of a tiny and unusually heavy neutron star that spins 25 times per second. The pulsar, named PSR J0348+0432 is the remains of a supernova explosion. Twice as heavy as our Sun, the pulsar would fit within the confines of the Denver metropolitan area; it’s just 20 kilometers across or about 12 miles. The gravity on this strange star is more than 300 billion times stronger than on Earth. At its center, where the intense gravity squeezes matter even more tightly together, a sugar-cubed-sized block of star stuff would weight more than one billion tons. Only three other pulsars outside globular clusters spin faster and have shorter periods.

J0348+0432 could easily fit within the confines of most American cities, including Denver, Colo. Want to see how big J0348+0432 is compared to your city? Check out this map tool. Zoom into or search for your city, enter 10 km into the radius distance field, and click on a point on the map.)
J0348+0432 could easily fit within the confines of most American cities, including Denver, Colo. Want to see how big J0348+0432 is compared to your city? Check out this map tool. Zoom into or search for your city, enter 10 km into the radius distance field, and click on a point on the map. Credit: Google Maps
In addition, a much larger white dwarf, the extremely hot, burned-out core of a Sun-like star, whips around J0348+0432 every 2.5 hours.

As a consequence, radio astronomers Ryan Lynch and colleagues who discovered the pulsar in 2011, realized the pair would enable scientists to test theories of gravity that were not possible before. Einstein’s general theory of relativity describes gravity as a curvature in spacetime. Like a bowling ball nestled in a stretched bedsheet, spacetime bends and warps in the presence of mass and energy. The theory, published in 1916, has withstood all tests so far as the simplest explanation for observed astronomical phenomena. Other theories of gravity make different predictions but these differences would reveal themselves only in extremely strong gravitational fields not found within our solar system. J0348+0432 offered the opportunity to study Einstein’s theory in detail.

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This video shows an artist’s impression of the exotic double object known as PSR J0348+0432. This system is radiating gravitational radiation, or ripples, in spacetime. Although these waves cannot be yet detected directly by astronomers on Earth they can be detected indirectly by measuring the change in the orbit of the system as it loses energy. Credit: ESO/L.Calçada

Antoniadis’ team combined observations of the white dwarf from the European Southern Observatory’s Very Large Telescope with the precise timing of the pulsar from other radio telescopes, including the Green Bank Telescope in West Virginia, Effelsberg 100 meter radio telescope in Germany, and the Arecibo Observatory in Puerto Rico. Astronomers predict such close pulsar binaries radiate gravity waves and lose minute amounts of energy over time causing the orbital period of the white dwarf companion to change slightly. The astronomers found that predictions for this change closely matched those of general relativity while competing theories were different.

“Our radio observations were so precise that we have already been able to measure a change in the orbital period of 8 millionths of a second per year, exactly what Einstein’s theory predicts,” states Paulo Freire, another team member, in the press release.

Sources:
ESO: Einstein Was Right – So Far
Astrophysical Journal: The Green Bank Telescope 350 MHz Drift-scan Survey II: Data Analysis and the Timing of 10 New Pulsars, Including a Relativistic Binary
Aspen Center for Physics Physical Application of Millisecond Pulsars meeting January 2013: The Compact Relativistic Binary PSR J0348+0432

The Sun Blasts Out Two CME’s Towards Mercury

the Solar Heliospheric Observatory (SOHO) captured this series of four images of a coronal mass ejection (CME) escaping the sun on the morning of April 25, 2013. The images show the CME from 5:24 a.m. to 6:48 a.m. EDT. This was the second of two CMEs in the space of 12 hours. Both are headed away from Earth toward Mercury. Credit: ESA&NASA/SOHO.

Over the past 24 hours, the Sun has erupted with two coronal mass ejections (CMEs), sending billions of tons of solar particles into space. While these CMEs are not directed at Earth, they are heading towards Mercury and may affect the Messenger spacecraft, as well as the Sun-watching STEREO-A satellites. One CME may send a glancing blow of particles to Mars, possibly affecting spacecraft at the Red Planet.

This solar radiation can affect electronic systems on spacecraft, and the various missions have been put on alert. When warranted, NASA operators can put spacecraft into safe mode to protect the instruments from the solar material.

The first CME began at 01:30 UTC on April 25 (9:30 p.m. EDT on April 24), and the second erupted at 09:24 UTC (5:24 a.m. EDT) on April 25. Both left the sun traveling at about 800 kilometers (500 miles per second).

See this animation from the STEREO-B spacecraft:

Animations of CMEs on April 25, 2013 from the STEREO-B spacecraft. Credit: NASA/Goddard Space Flight Center.

Source: NASA

Dust Complicates Determinations of the Distance to Galactic Center

The plane of our Milky Way galaxy (image credit: R. Bertero/deviantart, cropped by DM).  Understanding the nature of the obscuring dust, indicated partly by the dark regions bisecting the plane, is key to establishing a precise distance to the Galactic center.

Obtaining an accurate distance between the Sun and the center of our Galaxy remains one of the principal challenges facing astronomers. The ongoing lively debate concerning this distance hinges partly on the nature of dust found along that sight-line. Specifically, are dust particles lying toward the Galactic center different from their counterparts near the Sun? A new study led by David Nataf asserts that, yes, dust located towards the Galactic center is anomalous. They also look at accurately defining both the distance to the Galactic center and the reputed bar structure that encompasses it.

The team argues that characterizing the nature of small dust particles is key to establishing the correct distance to the Galactic center, and such an analysis may mitigate the scatter among published estimates for that distance (shown in the figure below).  Nataf et al. 2013 conclude that dust along the sight-line to the Galactic center is anomalous, thus causing a non-standard ‘extinction law‘.  

The extinction law describes how dust causes objects to appear fainter as a function of the emitted wavelength of light, and hence relays important information pertaining to the dust properties.

The team notes that, “We estimate a distance to the Galactic center of [26745 light-years] … [adopting a] non-standard [extinction law] thus relieves a major bottleneck in Galactic bulge studies.”

Various estimates for the distance to the Galactic center tabulated by Malkin 2013. The x-axis describes the year, while the y-axis features the distance to the Galactic center in kiloparsecs (image credit: Fig 1 from Malkin 2013/arXiv/ARep).

Nataf et al. 2013 likewise notes that, “The variations in both the extinction and the extinction law made it difficult to reliably trace the spatial structure of the [Galactic] bulge.”  Thus variations in the extinction law (tied directly to the dust properties) also affect efforts to delineate the Galactic bar, in addition to certain determinations of the distance to the Galactic center.  Variations in the extinction law imply inhomogeneities among the dust particles.

“The viewing angle between the bulge’s major axis and the Sun-Galactic centerline of sight remains undetermined, with best values ranging from from  13  to …  44 [degrees],” said Nataf et al. 2013 (see also Table 1 in Vanhollebekke et al. 2009).  The team added that, “We measure an upper bound on the tilt of 40 [degrees] between the bulge’s major axis and the Sun-Galactic center line of sight.”

However, the properties of dust found towards the Galactic center are debated, and a spectrum of opinions exist.  While Nataf et al. 2013 find that the extinction law is anomalously low, there are studies arguing for a standard extinction law.  Incidentally, Nataf et al. 2013 highlight that the extinction law characterizing dust near the Galactic center is similar to that tied to extragalactic supernovae (SNe), “The … [extinction] law toward the inner Galaxy [is] approximately consistent with extra-galactic investigations of the hosts of type Ia SNe.”

The delineation of the bar at the center of our Milky Way galaxy by Nataf et al. 2013. The bar is closer toward the Sun in the 1st Galactic quadrant. The center line represents the direction toward the constellation of Sagitarrius (image credit: Fig 17 from Nataf et al. 2013/arXiv/ApJ).
Left, the delineation of the bar at the center of the Milky Way by Nataf et al. 2013. The centerline represents the direction towards Sagittarius (image credit: Fig 17 from Nataf et al. 2013/arXiv/ApJ).  Right, a macro view of the Galaxy highlighting the general orientation and location of the Galactic bar (image credit: NASA/Wikipedia).  The Galactic bar is not readily discernible in the distribution of RR Lyrae variables.

Deviations from the standard extinction law, and the importance of characterizing that offset, is also exemplified by studies of the Carina spiral arm.  Optical surveys reveal that a prominent spiral arm runs through Carina (although that topic is likewise debated), and recent studies argue that the extinction law for Carina is higher than the standard value (Carraro et al. 2013Vargas Alvarez et al. 2013).  Conversely, Nataf et al. 2013 advocate that dust towards the Galactic center is lower by comparison to the standard (average) extinction law value.

The impact of adopting an anomalously high extinction law for objects located in Carina is conveyed by the case of the famed star cluster Westerlund 2, which is reputed to host some of the Galaxy’s most massive stars.  Adopting an anomalous extinction law for Westerlund 2 (Carraro et al. 2013Vargas Alvarez et al. 2013) forces certain prior distance estimates to decrease by some 50% (however see Dame 2007).  That merely emphasizes the sheer importance of characterizing local dust properties when establishing the cosmic distance scale.

In sum, characterizing the properties of small dust particles is important when ascertaining such fundamental quantities like the distance to the Galactic center, delineating the Galactic bar, and employing distance indicators like Type Ia SNe.

The Nataf et al. 2013 findings have been accepted for publication in the Astrophysical Journal (ApJ), and a preprint is available on arXiv.  The coauthors on the study are Andrew Gould, Pascal Fouque, Oscar A. Gonzalez, Jennifer A. Johnson, Jan Skowron, Andrzej Udalski, Michal K. Szymanski, Marcin Kubiak, Grzegorz Pietrzynski, Igor Soszynski, Krzysztof Ulaczyk, Lukasz Wyrzykowski, Radoslaw Poleski.  The Nataf et al. 2013 results are based partly on data acquired via the Optical Graviational Lensing Experiment (OGLE).  The interested reader desiring additional information will find the following pertinent: Udalski 2003Pottasch and Bernard-Salas 2013Kunder et al. 2008Vargas Alvarez et al. 2013Carraro et al. 2013Malkin 2013Churchwell et al. 2009, Dame 2007Ghez et al. 2008Vanhollebekke et al. 2009.

The Nataf et al. 2013 results are based partly on observations acquired by the OGLE survey (image credit: OGLE team).