RASNZ Electronic Newsletter July 2017

The RASNZ Email newsletter is distributed by email on or near the 20th of each month. If you would like to be on the circulation list This email address is being protected from spambots. You need JavaScript enabled to view it. for a copy. The latest issue is below.

Email Newsletter Number 199

Affiliated Societies are welcome to reproduce any item in this email newsletter or on the RASNZ website http://www.rasnz.org.nz/ in their own newsletters provided an acknowledgement of the source is also included.


1. Third International Starlight Festival, 13-15 October
2. Harry Williams Astrophotography Competition
3. The Solar System in July
4. Solar Probe
5. Xenon Calibrates Comets' Relation to Earth
6. Orbiting Pair of Supermassive Black Holes
7. Gravitationally-lensed Supernova Found
8. Fast Radio Burst FRB 121102 (cont.)
9. How to Join the RASNZ
10. Gifford-Eiby Lecture Fund
11. Kingdon-Tomlinson Fund

1. Third International Starlight Festival, 13-15 October

The Third International Starlight Festival will be held at the Hermitage, Mt Cook over three days in 2017, 13-15 October.

The Festival will celebrate the Aoraki Mackenzie International Dark Sky Reserve (www.darkskyreserve.org.nz) whose mission is to encourage and protect dark skies free of light pollution in the Mackenzie, and to promote star gazing and astro-tourism. We do this by organizing a Starlight Festival every second year for the benefit of the public and international tourists. Astro-tourism in the Mackenzie at Tekapo and Mt Cook is now one of New Zealand?s biggest tourist attractions, with about 200,000 people coming to Tekapo annually, many from Asia and Europe, to see the stars.

The 2017 Festival will be our third, after very successful events in 2013 in Tekapo and 2015 at Twizel. The Festival will be a mixture of events including lectures, workshops, exhibitions, videos and documentaries, planetarium shows and of course, star-gazing. We have engaged three world-class speakers to come to Mt Cook for the Festival. They are:

  • Dr Natalie Batalha NASA Ames space scientist, Moffett Field (near San Francisco), California. (Time Magazine in April 2017 named her as one of the 100 most influential people on the planet). She will talk about ?A Planet for Goldilocks? and the search for habitable Earth-like planets
  • Kevin Govender, Director of the Office of Astronomy for Development of the International Astronomical Union, based in Cape Town, South Africa. He will talk about ?Astronomy for Humankind?.
  • Sze-leung Cheung, Director of the Office of Astronomy Outreach of the International Astronomical Union, based in Tokyo, Japan. He will talk about ?The threat of LEDs to astronomy and how to build a dark-sky-friendly future?.

All three are outstanding speakers, and Sze-leung Cheung is fluent in Chinese as well as English, so can give his talk in both languages to attract overseas tourists.

More details on the Third Starlight Festival and our keynote speakers are at www.starlightfestival.org.nz. On-line ticket sales will be available from mid-July. The website also has all accommodation options in and near Mt Cook.

Mark Gee from Wellington will show some of his stunning night-sky time-lapse animations and on the morning of Oct 14 will conduct an astro-photography workshop for everyone wanting to learn these techniques. Steve Chadwick from Palmerston North will show his amazing night sky animations and photography, as will also the renowned Fairlie and Tekapo astrophotographer, Fraser Gunn.

There is also an astro-photography exhibition with nine of New Zealand?s top astro-photographers exhibiting their images. The Festival features videos, exhibitions, workshops, planetarium shows and stargazing (at the new Mt Cook Observatory) over three days, 13-15 October.

-- John Hearnshaw, Chair, Aoraki Mackenzie International Dark Sky Reserve Board.

2. Harry Williams Astrophotography Competition

Calling all Astrophotographers, the 2017 Harry Williams Astrophotography Competition is now open for entries, this year our judge is world-renowned planetary photographer Damian Peach, in 2010, Damian became the only Briton to win the prestigious Astronomy Photographer of the Year Award for his composite photograph of Jupiter's moons, Ganymede and Io, orbiting the stormy surface of the Gas Giant.

Astronz has generously offered to sponsor the Deep Sky category with a Astronz $300 gift voucher as well as providing an Astronz beanie for the winner of each category!

Not only will the overall winner of the competition receive the coveted Harry Williams Astrophotography Trophy to adorn his or her mantelpiece for a year but they will also receive an OPTOLONG L-Pro light pollution filter worth $269 US dollars thanks to the very generous sponsorship of OPTOLONG Astronomical Filters.

As in previous years we are lucky to have Australian Sky & Telescope on board as sponsors of both the Solar System category and the Miscellaneous /Artistic category, the winners of these categories will receive a one year subscription to the magazine as well as the usual cash prize.

Also the winner of the Newcomers contest will receive a signed copy of 'Imaging the Southern Sky' by Steve Chadwick & Ian Cooper, more sponsors to be announced soon.

The competition cut-off date is August 31 and the competition awards will be announced at the annual Burbidge Dinner which is the Auckland Astronomical Society's premier annual event, keep an eye out on the society website for details on the forthcoming Burbidge dinner.

The competition rules and entry forms can be found on the Auckland Astronomical Society website http://www.astronomy.org.nz/new/public/default.aspx

-- From Jonathan Green's posting to the nzastronomers Yahoo group.

3. The Solar System in August

Dates and times shown are NZST (UT + 12 hours) unless otherwise stated.

Sunrise, Sunset and Twilight Times in May

Times are for Wellington. They will vary by a few minutes elsewhere in NZ.

                 August  1  NZST                August 31  NZST
       SUN: rise: 7.26am,  set: 5.28pm    rise:  6.45am,  set: 5.57pm
Twilights     morning       evening          morning       evening
Civil:    starts: 6.59am, ends: 5.55pm   starts: 6.20am, ends: 6.23pm
Nautical: starts: 6.26am, ends: 6.39pm   starts: 5.48am, ends: 6.55pm
Astro:    starts: 5.54am, ends: 7.01pm   starts: 5.16am, ends: 7.27pm

August Phases of the Moon (times NZST, as shown by GUIDE)

  Full moon:     August  8 at  6.11 am (Aug  7, 18:11 UT)
  Last quarter   August 15 at  1.15 pm (01:15 UT)
  New moon:      August 22 at  6.30 am (Aug 22, 18:30 UT)
  First quarter: August 29 at 12.13 pm (00:13 UT)

The Planets in August 2017

Mercury is visible in the early evening sky during the first part of August while Jupiter remains visible until later evening. Saturn is there all evening. In the morning Venus is bright before sunrise. Mars is not visible during the month.

MERCURY starts August as a prominent early evening object, magnitude 0.4 setting well over two hours after the Sun. The planet begins the month in Leo some 6.5° above Regulus. During August it loops into Sextans but its elongation from the Sun rapidly declines and as it does the planet loses brightness. On the 27th Mercury is at inferior conjunction between the Earth and Sun.

VENUS continues as an easily seen morning object although by the end of the month it rises less than 90 minutes before the Sun. During August it crosses Gemini and moves into Cancer on the 24th. On the morning of August 20 it will be joined by the crescent moon, some 8° to the right of the planet.

MARS remains too close to the Sun to observe during August, rising at best only 23 minutes before the Sun on the 31st.

JUPITER remains easily visible in the early evening sky, although by the end of August it will set mid evening. The planet is in Virgo below Regulus, their separation slowly decreasing. By the end of the month the two will be less than 4° apart. On the 25th the crescent moon will join them be some 6° below Jupiter.

SATURN is still well placed in the evening sky during August, not setting until after midnight. The planet is in Ophiuchus, its position changing very little during the month. It is stationary on the 25th. The moon will be less than 4° from Saturn on the 3rd of August. The two are close again on the 30th, this time 5° apart mid evening.

Outer Planets URANUS rises close to midnight at the beginning of August and two hours earlier by the end of the month. The planet remains in Pisces at magnitude 5.8. It is stationary on the 3rd.

NEPTUNE rises at 8.15 pm on August 1 advancing to a few minutes after sunset on the 31st. It is in Aquarius at magnitude 7.8.

PLUTO, magnitude 14.4, remains in Sagittarius. It will be less than a degree from the magnitude 2.9 star, pi Sgr, by the end of the month.

Minor Planets (1) CERES is in the morning sky, rising about 4.00 am by the end of August. It is in Gemini ending the month just over 5° from Pollux; magnitude 8.9.

(2) PALLAS is a morning object in Eridanus brightening from magnitude 9.5 to 9.0 during August.

(4) VESTA is an 8th magnitude object in Leo during August. At the beginning of the month it will be some 6° to the right of Mercury in the early evening. By the end of August, Vesta will be setting an hour after the Sun.

(7) IRIS is a morning object brightening from magnitude 9.2 to 8.6 during the month. Although starting August in Pisces it soon moves into Aries where it is 1° from Beta Ari, mag 2.6 on the 13th and less than 2° from Alpha Ari at the end of the month.

(3122) Florence has a diameter of a few kilometres. Discovered in 1981 it is listed as a potential threat to Earth. It will be some 7 million kilometres from the Earth at the end of August with magnitude 8.8. By then it should have an apparent motion over 20 arc-minutes per hour. Its path will see it pass some 16° from Fomalhaut on August 27 and less than 15° from Altair on September 2.

4. Solar Probe

NASA's Parker Solar Probe, set to launch in 2018, will be humanity's first effort to "touch the Sun," revolutionizing our understanding of the Sun's corona, the solar wind, and the greater heliosphere. Parker Solar Probe

NASA has announced that they are retitling the Solar Probe Plus, humanity's first mission to the outer layers of the Sun, the Parker Solar Probe. The new name honours astrophysicist Eugene Parker, whose years' of work in the field known as "space weather" have helped us understand the interactions between stars and their orbiting bodies.

In the latter half of the 1950s, a young professor teaching astronomy and physics at the University of Chicago's Enrico Fermi Institute, Eugene Parker, published an article in the Astrophysical Journal entitled "Dynamics of the interplanetary gas and magnetic fields." The paper introduced the idea of a wind emanating from the Sun, a concept so controversial that two reviewers rejected the paper. In the end, it was only published because Subrahmanyan Chandrasekhar, the journal's science editor at the time (and no stranger himself to rejection for revolutionary thinking), overruled the reviewers' decisions.

Much of Parker's work at the time focused on the Sun's radiation and its potential effects on the planets. In his 1958 paper, Parker hypothesized that there was a constant stream of high-energy particles and radiation escaping from the surface of the Sun, an idea that ran contrary to the accepted view of the time that this space contained only a vacuum. But it was controversial only for a little while ? in 1962 Mariner 2 confirmed the existence of the solar wind.

While observations proved the solar wind existed, they weren't able to fully answer how or why the Sun's tenuous outer atmosphere, or corona, should sear at a temperature of millions of degrees. The Sun's visible surface, after all, is only several thousand degrees, so something must be heating the matter farther from the Sun, but scientists have long debated what that process could be. The Parker Solar Probe will address that fundamental question, completing seven flybys of Venus between 2018 and 2024 to slowly spiral into orbits that take it within 3.9 million miles (9 solar radii) of the Sun.

At its closest approach, the spacecraft will hurtle around the Sun at 200 km/s at a distance nearly ten times closer to the Sun than Mercury (on average), and seven times closer than any spacecraft has ever come before. The probe will perform its scientific investigations in a region of intense heat and radiation, and its instruments must thereby be protected by a 4.5-inch thick carbon-composite heat shield, able to withstand temperatures of up to 1400°C.

The mission's main goal is to trace heat and energy flow through the corona and explore what causes charged particles to accelerate away from the surface of the Sun. To that end, the instrument aboard the Parker Solar probe will study every aspect of the Sun from its magnetic and electric fields to the solar wind.

  • The FIELDS instrument consists of five voltage sensors as well as three magnetometers, sensors which measure magnetic field. It will make detailed measurements of the corona's electric and magnetic fields, as well as other gauging electron temperature and plasma density.
  • The ISIS instrument will observe solar energetic particles (SEPs) such as electrons, protons, and heavy ions accelerated to energies as high as 100 MeV, correlating these particles with larger coronal structures and the solar wind.
  • WISPR, a wide field telescope imager, will supplement the raw data captured by the FIELDS and ISIS instruments with high-quality photographs.
  • SPAN-A+ and SPAN-B will measure the velocity, temperature, and density distributions of the electrons, protons, and helium ions.

Together, these instruments will help unlock the answers to the Sun's most puzzling questions ? all the while helping to protect a society that is becoming increasingly dependent on satellites and other technology vulnerable to the threats of space weather.

-- From an article by Chris Stubenrauch on Sky & Telescope's website at http://www.skyandtelescope.com/astronomy-news/nasa-parker-solar-probe-touch-sun/

---------- In the late 1920s the English mathematical physicist E A Milne also suggested the existence of a solar wind. See 'Beating the Odds: The Life and Times of E A Milne' by Meg Weston Smith. -- Ed.

5. Xenon Calibrates Comets' Relation to Earth

Xenon measured by the European Space Agency's Rosetta spacecraft has shed light on a long-standing mystery about the role comets played in Earth's formation.

A noble gas is serving as a key tracer for sleuthing out early solar system formation. Researchers led by Bernard Marty (CNRS, France) announced June 9th in Science that the chemical signature of the gas xenon ? an element that exists in minute quantities in Earth's atmosphere ? was also detected in the tenuous envelope surrounding Comet 67P/Churyumov-Gerasimenko in the final months of the European Space Agency's Rosetta mission.

Xenon is a noble gas, element number 54 on the periodic table. Because it doesn't react with other elements, it serves a crucial role in tracing the source of proto-solar material that ultimately created Earth and other planets. This gas has 10 different isotopes, each containing a different number of neutrons. The lightest isotopes of xenon are created during supernova explosions; its medium-weight isotopes form when low- to medium- mass stars enter the asymptotic giant phase of their lives; and the very heaviest occur during energetic neutron star mergers.

?Xenon is the heaviest stable noble gas and perhaps the most important because of its many isotopes that originate in different stellar processes,? says Marty in a recent press release. ?Each one provides an additional piece of information about our cosmic origins.?

By accounting for this measured loss, scientists soon realized that the levels of heavy isotopes in Earth's primordial xenon mix (referred to as ?U-xenon?) were lower than that found in xenon's ratios elsewhere in the solar system, such as in the solar wind and asteroids. Such a discrepancy has become known as the ?xenon paradox.?

Comets have unique compositions because they formed very far from the Sun. For example, their ratios of deuterium to hydrogen are consistently higher than anywhere else in the solar system. Should xenon show similar discrepancies?

To get the key samples from Comet 67P, Rosetta had to get within just 5 to 8 km of the nucleus. This was a challenging manoeuvre for the mission's navigation team, as dust sublimating off the comet can confuse the spacecraft's star trackers. ESA controllers decided to perform the critical manoeuvre in the last half of May 2016.

The spacecraft used a mass spectrometer in its ROSINA instrument suite to measure xenon isotope levels over a span of three weeks. This extended study identified seven isotopes of xenon, with a relatively abundant blend of light isotopes relative to heavy ones. This ratio is markedly different from that seen in asteroids and the solar wind today ? but similar to the predicted U-xenon ratio of primordial Earth. Marty and his team conclude that comets contributed 22% to the mix of xenon sources delivered to Earth.

This is also the first time that scientists were able to establish a definitive link between comets ? thought to represent pristine examples of the early solar system ? and the atmospheric composition of Earth. Comets delivering xenon to the early Earth likely contributed prebiotic material such as the amino acid glycine and phosphorus, also detected by Rosetta on Comet 67P.

But Earth's water lacks the high deuterium to hydrogen ratio seen in Comet 67P, so comets must have played a limited role in delivering water to the Earth. A more likely source for that, geochemists now suspect, was the population of water-rich carbonaceous chondrite asteroids.

?This conclusion is in accord with previous measurements performed by Rosetta,? says Kathrin Altwegg (University of Bern, Switzerland) in a recent press release, ?including the unexpected detections of molecular oxygen and di-sulphur, and the high deuterium-to-oxygen ratio observed in the comet water.?

Earth is unique in the solar system as the only world which wears its extensive oceans of liquid water on the outside ? every other world inside the ?frost line? of the inner solar system is bone dry.

Standard models of solar system formation predict an early creation of the outer gas giant worlds, with untold numbers of comets lingering farther out in the Kuiper Belt and trillions more flung to the distant realm of the Oort Cloud by gravitational encounters with the outer planets. Now, we're seeing just how comets May have contributed to the present composition of the inner rocky worlds as well.

Samples from Comet 81P/Wild returned by NASA's Stardust mission suggest that elements originating from the interior of the early solar nebula ? particularly isotopes of oxygen ? were transported outward through the early solar system.

No future comet sample return mission is in the works, though the bonanza of science returned by Rosetta certainly shows that another Stardust follow up is due.

When it comes to unravelling the riddle of early solar system formation, the new mantra for the future might be to ?follow the xenon.?

From an illustrated article by David Dickinson on Sky & Telescope's webpage at http://www.skyandtelescope.com/astronomy-blogs/astronomy-space-david-dickinson/rosetta-finds-clues-to-xenon-paradox/

6. Orbiting Pair of Supermassive Black Holes

Using the super-sharp radio 'vision' of the National Science Foundation's Very Long Baseline Array (VLBA), astronomers have made the first detection of orbital motion in a pair of supermassive black holes in a galaxy some 750 million light-years from Earth.

The two black holes, with a combined mass 15 billion times that of the Sun, are likely separated by only about 24 light-years, extremely close for such a system.

"This is the first pair of black holes to be seen as separate objects that are moving with respect to each other, and thus makes this the first black-hole 'visual binary'" said Greg Taylor, of the University of New Mexico (UNM).

Supermassive black holes, with millions or billions of times the mass of the Sun, reside at the cores of most galaxies. The presence of two such monsters at the centre of a single galaxy means that the galaxy merged with another sometime in the past. In such cases, the two black holes themselves May eventually merge in an event that would produce gravitational waves that ripple across the universe.

"We believe that the two supermassive black holes in this galaxy will merge," said Karishma Bansal, a graduate student at UNM, adding that the merger will come at least millions of years in the future.

The galaxy, an elliptical galaxy called 0402+379, after its location in the sky, was first observed in 1995. It was studied in 2003 and 2005 with the VLBA. Based on finding two cores in the galaxy, instead of one, Taylor and his collaborators concluded in 2006 that it contained a pair of supermassive black holes.

The latest research, which Taylor and his colleagues are reporting in the Astrophysical Journal, incorporates new VLBA observations from 2009 and 2015, along with re-analysis of the earlier VLBA data. This work revealed motion of the two cores, confirming that the two black holes are orbiting each other. The scientists' initial calculations indicate that they complete a single orbit in about 30,000 years.

"We need to continue observing this galaxy to improve our understanding of the orbit, and of the masses of the black holes," Taylor said. "This pair of black holes offers us our first chance to study how such systems interact," he added.

The astronomers also hope to discover other such systems. The galaxy mergers that bring two supermassive black holes close together are considered to be a common process in the universe, so astronomers expect that such binary pairs should be common.

"Now that we've been able to measure orbital motion in one such pair, We're encouraged to seek other, similar pairs. We May find others that are easier to study," Bansal said.

The VLBA, part of the Long Baseline Observatory, is a continent-wide radio telescope system using ten, 240-ton dish antennas distributed from Hawaii to St. Croix in the Caribbean. All ten antennas work together as a single telescope with the greatest resolving power available to astronomy. That extraordinary resolving power allows scientists to make extremely fine measurements of objects and motions in the sky, such as those done for the research on 0402+379.

-- From a press release from the Long Baseline Observatory in Socorro, New Mexico, forwarded by Karen Pollard.

7. Gravitationally-lensed Supernova Found

An international team of astronomers has, for the first time, seen a cosmic magnification of the light from a class of supernova called Type Ia. Type Ia supernovae -- often referred to as "standard candles" because of their well-known intrinsic brightness -- are frequently used by astronomers to accurately measure the expansion rate of our universe, as well as the amount of dark energy, which is thought to be accelerating this expansion.

Finding a magnified, or "gravitationally lensed," Type Ia supernova is like discovering a brighter candle with which to view the universe. The researchers say this discovery is the first of many to come, and that having a whole collection of similarly lensed Type Ia supernovas will lead to more precise measurements of our universe's most fundamental traits.

Gravitational lensing occurs when the gravity of a cosmic object, such as a galaxy, bends and magnifies the light of a more distant object. The effect can cause galaxies to appear strangely twisted, and even produce multiple images of the same object. While this phenomenon of gravitational lensing has been observed many times since the early 20th century, when it first was predicted by Albert Einstein, imaging a lensed Type Ia supernova has proven formidably difficult, until now.

In the new study, published April 21 in the journal Science, the researchers imaged the Type Ia supernova called iPTF16geu and found it duplicated into four different images.

"Resolving, for the first time, multiple images of a strongly lensed 'standard candle' supernova is a major breakthrough," says Ariel Goobar, a professor with the Oskar Klein Centre at the University of Stockholm, Sweden, and a lead author of the study. "Normally, when we view a lensed object, we don't know the intrinsic brightness of that object, but with a Type Ia supernova, we do. This will allow us to better quantify and understand the phenomenon of gravitational lensing."

Goobar and his group are partners in two Caltech-led international scientific collaborations -- the intermediate Palomar Transient Factory (iPTF) and the Global Relay of Observatories Watching Transients Happen (GROWTH) project. The iPTF takes advantage of the Palomar Observatory and its unique capabilities to scan the skies and discover, in near real-time, fast-changing cosmic events such as supernovas. GROWTH manages a global network of researchers and telescopes that can swiftly perform follow-up observations to study these transient events in detail.

Within two months of detection, the team observed the iPTF16geu supernova with the NASA/ESA Hubble Space Telescope; the adaptive-optics instruments on the W. M. Keck Observatory atop Maunakea, Hawaii; and the VLT telescopes in Chile. Apart from producing a striking visual effect, capturing the image of a strongly lensed Type Ia supernova such as iPTF16geu is extremely useful scientifically. Astronomers can measure very accurately how much time it takes for the light from each of the multiple images of the supernova to reach us. The difference in the time of arrival can then be used to estimate with a high precision the expansion rate of the universe, known as the Hubble Constant.

Another unique advantage of lensed Type Ia supernovas is that they can be identified with relatively small telescopes, such as the 48-inch Samuel Oschin Telescope at Palomar Observatory, which was used to image the iPTF16geu supernova. Larger telescopes are in high demand, and equipped with narrow-field cameras that take too much time to routinely scan the sky. The iPTF project scanned one-fifteenth of the visible sky every night. Its successor, the Zwicky Transient Facility (ZTF), set to begin observing this [northern] summer, will scan the skies even faster, and is capable of covering the entire accessible sky every night. By scanning large swaths of the sky, astronomers can sift through thousands of cosmic objects to find rare events such as the lensing of a Type Ia supernova.

While ZTF will be 10 times faster than iPTF, new facilities such as the Large Synoptic Survey Telescope (LSST) will be 10 times faster than ZTF. Clearly, the discovery of iPTF16geu suggests a wealth of new science that will be made possible with the LSST.

The study of iPTF16geu is already delivering interesting results. Using data from Keck and Hubble the team calculated that the lensing matter in the galaxy magnifying iPTF16geu has a mass up to 10 billion times that of the Sun and a radius of nearly 3,000 light-years. Compared to other lensing objects, this is relatively tiny. Studies of unusual lensed objects like this give astronomers a new peek into gravitational lensing and May redefine what we know about the factors, such as dark matter and Einstein's general theory of relativity, that contribute to lensing.

Reference: "iPTF16geu: A Multiply-Imaged Gravitationally Lensed Type Ia Supernova," A. Goobar et al., 2017 Apr. 21, Science [http://science.sciencemag.org].

-- From a Caltech press release forwarded by Karen Pollard.

8. Fast Radio Burst FRB 121102 (cont.)

Ground- and space-based observations have now shed intriguing new light on a mysterious radio source. (See Newsletter No. 194, 20 February 2017, Item 4.)

A puzzling source of ultra-brief radio bursts is slowly giving up some of its secrets. Three new papers, published on the arXiv preprint server in late May, have presented surprising new results on the only known repeating fast radio burst, dubbed FRB 121102. But despite the concerted efforts of some of the largest observatories, both on the ground and in space, the true nature of these enigmatic events remains a mystery.

Fast radio bursts are very brief explosions of radio waves, first discovered at the 64-meter Parkes radio telescope in Australia. Because of their unpredictability, their short duration (on the order of milliseconds), and the small field of view of a typical radio telescope, such bursts are hard to spot. But from the two dozen or so found so far, it follows that there must be thousands of these bursts occurring all over the sky every day.

Of these, FRB121102, first detected by the 305-meter Arecibo radio telescope in Puerto Rico, is special. After its discovery on 2012 November 2 (hence its name), it became the first of its kind to repeat, producing many additional bursts of radio waves. Whatever FRBs might be, they?re apparently not some one-off cataclysm.

In 2016 observations by the Very Large Array in New Mexico and the European VLBI Network succeeded in precisely pinpointing the sky location of the repeating radio source. It turned out to coincide with a remote, dim dwarf galaxy that also hosts a faint persistent source of radio waves. A paper published earlier this year already revealed that the FRB and the persistent radio source are separated by less than 12 milliarcseconds.

Ground- and space-based observations by a large international team of astronomers have now shed intriguing new light on this mysterious FRB. In February the dwarf galaxy ? 3.2 billion light-years away in southern Auriga ? was studied in detail by the Hubble Space Telescope, following earlier observations by the 8.1-meter Gemini-North telescope at Mauna Kea, Hawaii, and by NASA?s Spitzer Space Telescope. Meanwhile, a Japanese team also observed the puny galaxy with the 8.2-meter Subaru telescope, also at Mauna Kea.

The new observations reveal that the bursts originate in an active, compact star-forming region some 4,500 light-years across in the outskirts of the tiny galaxy. According to team member Jason Hessels (ASTRON, the Netherlands Institute for Radio Astronomy), this strongly suggests that the source of the bursts is a relatively young object ? probably a recently formed neutron star. ?FRB121102 might be considered a pulsar on steroids,? says Hessels. But it?s not yet clear whether the intermittent bursts are part of a regularly repeating signal, characteristic of pulsars.

The burst location has also been monitored by ESA?s XMM Newton observatory (in September 2016) and by NASA?s Chandra X-ray Observatory (in November 2016 and January 2017). But although Arecibo and the 110-meter Green Bank Telescope in West Virginia recorded a total of 12 new bursts during these periods (two of which were detected by both instruments), nothing was seen in X-rays. This indicates that the bursts? source is not just a scaled-up version of the young pulsar at the heart of the Crab Nebula. The Crab pulsar also emits giant radio flares (albeit half a million times less powerful than FRB121102!), but it?s a conspicuous X-ray source too.

Still, Hessels believes that the culprit must be a young stellar remnant ? maybe a rapidly spinning magnetar: a strongly magnetized neutron star. The faint persistent radio source could be the shock wave from the original supernova explosion, or a so-called pulsar wind nebula. Then again, known magnetars also produce powerful bursts of X-rays and gamma rays, which have not (yet) been observed in the case of FRB121102.

One of the other nagging questions is whether or not the repeating source is representative of all FRBs. No other fast radio bursts have been seen to repeat, despite various monitoring programs. Therefore, some researchers believe the repeater to be the odd one out. One of them is radio astronomer Duncan Lorimer of West Virginia University, who discovered the first FRB in Parkes data from 2001. ?I suspect there May be multiple classes,? he says.

-- From Govert Schilling's article at http://www.skyandtelescope.com/astronomy-news/homing-source-mysterious-fast-radio-burst/ Where references are listed.

9. How to Join the RASNZ

RASNZ membership is open to all individuals with an interest in astronomy in New Zealand. Information about the society and its objects can be found at http://rasnz.org.nz/rasnz/membership-benefits A membership form can be either obtained from This email address is being protected from spambots. You need JavaScript enabled to view it. or by completing the online application form found at http://rasnz.org.nz/rasnz/membership-application Basic membership for the 2017 year starts at $40 for an ordinary member, which includes an electronic subscription to our journal 'Southern Stars'.

10. Gifford-Eiby Lecture Fund

The RASNZ administers the Gifford-Eiby Memorial Lectureship Fund to assist Affiliated Societies with travel costs of getting a lecturer or instructor to their meetings. Details are in RASNZ By-Laws Section H.

For an application form contact the Executive Secretary This email address is being protected from spambots. You need JavaScript enabled to view it., Nichola van der Aa, 32A Louvain Street, Whakatane 3120.

11. Kingdon-Tomlinson Fund

The RASNZ is responsible for recommending to the trustees of the Kingdon Tomlinson Fund that grants be made for astronomical projects. The grants May be to any person or persons, or organisations, requiring funding for any projects or ventures that promote the progress of astronomy in New Zealand. Applications are now invited for grants from the Kingdon-Tomlinson Fund. The application should reach the Secretary by 1 November 2016. Full details are set down in the RASNZ By-Laws, Section J. For an application form contact the RASNZ Executive Secretary, This email address is being protected from spambots. You need JavaScript enabled to view it. Nichola van der Aa, 32A Louvain Street, Whakatane 3120.


"We all know the Moon landing was staged. It was filmed by Stanley Kubrick. However, it cost an insane amount of money as Kubrick was a perfectionist and demanded they film on location." -- Liberty Memes.

"There is still no cure for the common birthday." -- John Glenn.

Newsletter editor:

Alan Gilmore Phone: 03 680 6817
P.O. Box 57 Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Lake Tekapo 7945
New Zealand