sciet rnal - astronomy.org.nz · apollo 11 moon landing, next year on july 20th. ‘the people’s...

SOCIETY JOURNALHow old are the oldest stars?MONDAY 10 DECEMBER. 2018 AT 8.00PM

One of the most difficult things in astronomy is working out the ages of stars. It requires comparing models of how stars evolve to

the parameters we observe. Myself and Assoc. Prof. Elizabeth Stanway have improved our stellar models of stars that are similar

to the Sun, this was to improve our modelling of stars older than 100 million years old. To test them we worked out the age of

the oldest star clusters, globular clusters, we know. We found that previous estimates may have over estimated the ages by a few

billion years! I’ll discuss what we did, why we found the younger ages, whether we should believe them and the implications for

modelling of gravitational wave events. The latter having recently been awarded a Marsden fund grant for us to continue our

study.

I obtained my MA and MSci degrees from the University of Cambridge in 2001. I stayed at the University to study for my PhD

in astrophysics at the Institute of Astronomy. After this I undertook postdoctoral research at the Institut d’Astrophysics de Paris,

Queen’s University Belfast and the Institute of Astronomy. In 2011 I was appointed as a Lecturer of Astrophysics at The University

of Auckland.

In addition to my research activities I am also keen to participate in public understanding of science activities and have helped

out at open days for previous departments. I have also given many public talks in Inverness, Chester, Antrim and Cambridge. My

talks are on various subjects such as: “The Birth, Life and Death of Stars”, “Stars in their death throes” and “Supernova Kicks and

Runaway Stars”..

WITH DR JJ ELDRIDGE

2 SOCIETY JOURNAL, DECEMBER 2018

AAS Astrophotography Group - November and December 2018by Shaun Fletcher, AAS

IN NOVEMBER THE AAS ASTROPHOTOGRAPHY GROUP MEETING FEATURED STEVE LANG GIVING A PRESENTATION ONIS ADVENTURES IN COLLIMATION OF RITCHEY CHRETIEN TELESCOPE

The November AAS Astrophotography group was held at Stardome on the 19th November

Prior to the workshop we reviewed a slideshow of images that members have posted to the group Facebook page, which continue to be of excellent quality. Images of the bright comet 46P Wirtanen are an interesting appearance this month.

After a cancellation Steve Lang stepped in at the last minute to give a presnetation on collimation, focused on his experiences with the challenging issue of RC telescope collimation, which seems uniquely tricky due to the nature of the two mirrors!

Of special interest were the collimation masks/software which Steve showed and discussed, which certainly represent a new appraoch which may be very useful to many people. Steve has 3d printed several including an impressive Tri-Bahtinov mask.

Several other members brought along collimation aids such as artificial stars and laser collimators, and there was an interesting discussion.

IN DECEMBER THE GROUP MEETING TOPIC WILL BE IMAGING OF THE SUN AND SOLAR TRANSITS OF THE ISS WITH OTTO GRUEBL

Otto has produced a long series of remarkable solar images, has spoken to the society before, and is a frequent contributor to the group. His full solar disc images in CaK show amazing detail, and he has produced numerous fascinating images of the ISS transiting the solar disc. He will offer some more detailed information about his methods and equipment.

Slideshows supporting the meetings and the files used in these talks, along with frequent discussion and where possible assistance with your imaging, are available from the AAS Astrophotography Group (AAS members only) Facebook page, which can be accessed at https://www.facebook.com/groups/AASASTROPHOTOGRAPHY/

A Tri Bahtinov Mask for Aiding Collimation and Focusing of Telescopes

3WWW.ASTRONOMY.ORG.NZ

Film Night Novemberby Gavin Logan

November’s Film Night featured a Sky at Night special on planetary exploration. It covered everything from Mars Rovers to the hunt for other solar systems by the Kepler space telescope. In depth interviews with planetary scientist and some amazing images taken by unmanned probes we included in the film. There were some flash backs to Patrick Moore’s Sky at Night shows from the 1950s to 1980s to show just how much the knowledge and thinking about the planets has progressed in the last 60 years. It showed what has been achieved by successive unmanned space probes.

It was followed by a short film on the two Voyager space probes. Next month Film Night will be on 17th December at Stardome and will start mmediately following the astrophotography group and will be a full length science fiction movie composed by a well known astronomer.

‘THE PEOPLE’S MOON’

Fraser Grut is the director of Frog - a film studio based in Auckland.“I’m working with Buzz Aldrin and his foundation on a global film project called, ‘The People’s Moon’, for the 50th anniversary of the Apollo 11 moon landing, next year on July 20th.

‘The People’s Moon is a global legacy project that unites humanity through the 50th anniversary celebration of the Apollo 11 moon landing. It celebrates the human achievement of landing on the moon whilst giving the people of today permission to proclaim their life defining dream to the world.’

I’m looking for people with stories/memories of their experience watching/listening to the moon landing in 1969.

We’re wanting to recreate a number of these in short film format.”

Please contact Fraser at [email protected]


One of the biggest events to take place during the 2009 International Year of Astronomy was the 100 Hours of Astronomy as a Global Cornerstone Project. In January of 2019, a new 100 Hours of Astronomy event will be taking place as part of the IAU 100 celebrations. This is a 100-hour, round-the-clock, round-the-globe celebration composed of a broad range of activities aimed at involving the public. The event will take place over four days and nights, from 10-13 January. During this period, people from around the globe will share the experience of observing the sky. For many, it will be their first glimpse of the wonders of the heavens through a telescope. For others, it is the perfect opportunity to impart their knowledge and excitement, helping unveil the cosmos to fresh and eager eyes.

Hundreds of local events are being planned by science facilities and astronomy enthusiasts around the world, including telescope observing sessions, exhibitions, special shows and more. In many countries there will be public lectures by specially selected speakers, experts in astronomy, keen to participate in this planet-wide venture.

To keep track of developments and to promote sidewalk astronomy events effectively during the 100 hours, events are registered online. Anyone can set up an event, whether it is screening astronomy videos for a few hours on a single day or a 100-hour marathon event; only imagination sets the limit. The activities and events of 100 Hours of Astronomy will bring fresh audiences to astronomy and perhaps inspire young and budding scientists to pursue a career in astronomy.

100 Hours of Astronomy is a venture of breathtaking scope that seeks to involve people from all walks of life around the globe and conveys a multitude of messages, from the personal benefit of astronomical knowledge to the pressing issue of curbing light pollution. Clear your agenda now for 100 hours of discovery!

The 100 Hours of Astronomy global project is organised as part of the IAU100 celebrations. In 2019, the International Astronomical Union (IAU) is celebrating its 100th anniversary. To commemorate this milestone, the IAU is organising a year-long celebration to increase awareness of a century of astronomical discoveries as well as to support and improve the use of astronomy as a tool for education, development and diplomacy under the central theme “Under One Sky”.

To learn more about other activities and the organisation of the IAU100 year-long celebrations, please visit the IAU100 website. https://www.100hoursofastronomy.org

100 Hours of Astronomy 2019


Comet 46P/Wirtanen - RASNZOn December 16 periodic comet 46P/Wirtanen will pass 11.6 million km from us. At the same time the comet will be near its closest point to the Sun. That much is certain. How bright the comet will be very uncertain. Most likely it will appear as a faint spot of light with a slightly diffuse star-like centre. The size of the spot could be wider than one degree, two full-moon widths.

The Moon will be at first quarter on December 16th and full on the 23rd. So the evening sky will be bright when the comet is closest. The best chance of southern hemisphere observers seeing the comet is before closest approach when the night sky is less moonlit.

From NZ the comet will be moving down the sky toward the Pleiades/Matariki and Hyades star clusters through December. On December 16 it will be just to the right of the Pleiades/Matariki cluster.

Becaus the comet is likely to appear large and faint it is probably best searched for with binoculars rather than a telescope. Binoculars show a wide angle of sky making large faint objects more obvious.

46P/Wirtanen is a faint periodic comet that returns every 5.5 years or so. Since discovery in 1948 its return intervals have varied from 6.71 to 5.44 years. From 1947 to 1967 the comet’s closest point to the sun (perihelion) was 1.6 AU, 240 million km, outside the orbit of Mars. Between 1967 and 1986 encounters with Jupiter reduced the perihelion distance to 1.08 AU, just outside the Earth’s orbit. This time round the perihelion distance is 1.055 AU. The comet’s orbit passes 10.7 million km from Earth’s orbit so the pass on December 16 at 11.6 million km is nearly as close as the comet can get to us in its current orbit.

The designation 46P means that it is a periodic comet, one that has been seen to return. 1P/Halley is the most famous, returning at 76-80 year intervals. 2P/Encke is a faint comet that returns every 3.3 years. 67P/Churyumov-Gerassimenko became famous when the European Space Agency’s Rosetta spacecraft studied it. Around 380 periodic comets are now numbered. More are added every year.


DECEMBER PROGRAMME

Mon 3 8:00pm Intro to Astronomy with Chris Benton

Fri 7 7:00 pm Young Astronomers with Margaret Arthur

Mon 10 8:00pm Monthly Meeting December: Dr JJ Eldridge

Mon 17 7:00pm Astrophotography Group with Otto Gruebl followed byFilm Night December

JANUARY PROGRAMME

January is a rest month. Events resume in February

Calendar and Events

INTRO TO ASTRONOMY - DECEMBER 2018 MONDAY 03 DEC, 2018 AT 20:00HRS VENUE: STARDOME OBSERVATORY SPEAKER/HOST: CHRIS BENTON

Media Coverage of Astronomy News & Annual Fun Quiz

Decembers Introduction to Astronomy will be in two parts.

First up, AAS member John Wishart is going to present an interesting take on how the media have covered stories of astronomical interest over the past two years.

Sources of media have included newspapers, books, the internet, television, public speakers, social media and radio, covering a wide range of topics such as:

· The fate of the Universe

· Gravitational waves

· The Total Solar Eclipse

· Newly discovered exoplanets

Come along and join in discussion with your opinion on what sort of job they have done. Were items hyped-up with overly excited articles or perhaps even dumbed down? Were the articles accurate, or did they get some things wrong?

The annual fun quiz will follow and aim to be both lively and instructive, covering key principles from the Introduction to Astronomy sessions during the year.

Before we go home, I will also review the list of exciting topics lined up for 2019!

MONTHLY MEETING DEC - HOW OLD ARE THE OLDEST STARS? Monday 10 Dec, 2018 at 20:00Hrs Venue: Stardome Observatory Speaker/Host: Dr JJ Eldridge

One of the most difficult things in astronomy is working out the ages of stars. It requires comparing models of how stars evolve to the parameters we observe. Myself and Assoc. Prof. Elizabeth Stanway have improved our stellar models of stars that are similar to the Sun, this was to improve our modelling of stars older than 100 million years old. To test them we worked out the age of the oldest star clusters, globular clusters, we know. We found that previous estimates may have over estimated the ages by a few billion years! Ill discuss what we did, why we found the younger ages, whether we should believe them and the implications for modelling of gravitational wave events. The latter having recently been awarded a Marsden fund grant for us to continue our study.

I obtained my MA and MSci degrees from the University of Cambridge in 2001. I stayed at the University to study for my PhD in astrophysics at the Institute of Astronomy. After this I undertook postdoctoral research at the Institut d’Astrophysics de Paris, Queen’s University Belfast and the Institute of Astronomy. In 2011 I was appointed as a Lecturer of Astrophysics at The University of Auckland.

In addition to my research activities I am also keen to participate in public understanding of science activities and have helped out at open days for previous departments. I have also given many public talks in Inverness, Chester, Antrim and Cambridge. My talks are on various subjects such as: “The Birth, Life and Death of Stars”, “Stars in their death throes” and “Supernova Kicks and Runaway Stars”.

WELCOME NEW MEMBERS

Tejas Purani FamilyRavi Shah FamilySonia Minseo Kim YouthJillian Willmott Family


OUTREACH TEAM – SUMMER EVENTS

The Society is very active in public outreach. There are a growing number of events, particularly around the Matariki Festival, where the Society can fulfil its aim of taking astronomy to the public. This summer, the Society will be actively supporting the Auckland Botanic Gardens with their space-themed event running from December 2018 through to March 2019. There will be solar viewing days as well as night viewing – even though night comes late over summer.

Being part of the Outreach Team entails attending public events where members and the Society provide telescopes for viewing, discussing the night sky and the importance of dark skies and light pollution. This is a very satisfying team to be a part of as you really get to experience the wonder of astronomy over and over again. Even if you don’t have your own telescope, you’re very welcome to join the team and get involved.

Please contact Niven at [email protected] or on 021 935 261.

SOCIETY COUNCIL AND OFFICERS

President Bill Thomas (09) 478 4874 [email protected]

Vice-President Grant Christie (021) 0240 4992 [email protected]

Treasurer/ Outreach Niven Brown (021) 935 261 [email protected]

Secretary Gavin Logan (021) 144 1055 [email protected]

Membership Chris Benton (09) 424-4278 [email protected]

Curator of Instruments Steve Hennerley (027) 245 6441 [email protected]

Darren Woodley 021776481

Librarian Jerina Grewar (09) 444 5086 [email protected]

Journal Milina Ristić (029) 912 4748 [email protected]

Shaun Fletcher (09) 557 8686

Meetings Coordinator David Britten (09) 846 3657 [email protected]

Social Media Jonathan Green (09) 415 7284 [email protected]

Events [email protected]

Councillor Carolle Varughese 022 488 1906 [email protected]

SOCIETY CONTACTS

Auckland Astronomical Society Inc.PO Box 24187, Royal OakAuckland 1345, New Zealand

Website: www.astronomy.org.nzFacebook www.facebook.com/AuckAstroSocYoutube: www.youtube.com/channel/UC4W5_RJtWZBceOteC-8PTIAEmail: [email protected]

Meeting BroadcastsThe Society is now broadcasting many of its meetings online through our YouTube channel. You can watch the meetings live or at a later time. Perfect if you are unable to make it to the meeting or would just like to see the

talk again.

You can subscribe to our YouTube channel at:

https://www.youtube.com/channel/UC4W5_RJtWZBceOteC-8PTIA


Triton, Not Pluto or Eris, Is The Kuiper Belt’s Largest World?By Ethan Siegel , “Starts With A Bang” at Forbes.Com

Our Solar System is arguably the most well-studied corner of the Universe, with humanity having mapped out the planets, moons, and other significant bodies in our vicinity. Closest to the Sun, we have the densest worlds: made out of the heaviest elements and too small to hold onto a gas giant envelope. Beyond that are the asteroids, coinciding with the Solar System’s original frost line. Farther out than those are the four gas giant worlds, each with their own system of moons and rings. And finally, beyond that, are the trans-Neptunian objects: the frozen, comet-like worlds and bodies that are the farthest ones in our Solar System we’ve ever detected.

But which world is the true King of the Kuiper belt, the innermost of the trans-Neptunian objects? It’s not Pluto, the one with the greatest radius, nor Eris, the one with the greatest mass. Instead, Triton — the largest moon of Neptune — has them both beat. Here’s the bizarre story of how.

False-color image of Triton, Neptune’s largest moon, taken by spacecraft Voyager 2. This low-resolution image is the best photograph that Voyager 2 snapped of Neptune’s largest moon, just 2 days before closest approach.TIME LIFE PICTURES/NASA/THE LIFE PICTURE COLLECTION/GETTY IMAGES

At first glance, you might think this is crazy. Triton, after all, isn’t located in the Kuiper belt, but is one of Neptune’s moons. It isn’t just some random moon of Neptune, either; it’s by far the most prominent. It’s the largest of Neptune’s moons and one of the largest moons overall in the Solar System, with only Earth’s Moon, Saturn’s Titan, and the four Galilean moons of Jupiter surpassing it. Triton is the first satellite of

Neptune ever discovered, having been spotted in October of 1846: just months after Neptune itself was first announced.

So if it’s an actual, literal moon of Neptune, how could it possibly be classified as a trans-Neptunian object? In astronomy — as opposed to some other fields — it isn’t merely what your properties are today or where you’re located now that matters. The history of how you formed and arrived at your current location are parts of the story that simply cannot be ignored.

When you rank all the moons, small planets, and dwarf planets in our Solar System, you find that Triton, the 7th largest moon, has more similarities to Pluto than it does to anything else in the Solar System.MONTAGE BY EMILY LAKDAWALLA. DATA FROM NASA / JPL, JHUAPL/SWRI, SSI, AND UCLA / MPS / DLR / IDA, PROCESSED BY GORDAN UGARKOVIC, TED STRYK, BJORN JONSSON, ROMAN TKACHENKO, AND EMILY LAKDAWALLA

Triton, being a large, prominent moon that orbits its home planet every 6 days, looks pretty normal on most accounts. Until, that is, you take a look at the bizarre and unnerving fact of how it orbits. All of the other large moons in the Solar System,

• orbit in the same direction as the planets revolve around the Sun,

• orbit in roughly the same plane that the planets orbit the Sun (the ecliptic plane),

• and have densities that are in line with the predicted densities for solid bodies that formed at their particular, current distance from the Sun.

All of the Solar System’s large moons have these


properties, except for Triton. Instead, Triton orbits around Neptune in the opposite direction (clockwise) from how Neptune rotates on its axis and revolves around the Sun (counterclockwise), and is inclined to the ecliptic plane of the Solar System at an unusual angle of 130°. This retrograde orbital motion of Triton is the key to piecing together this mystery.

The orbit of Triton (red) has a 157° tilt in comparison to moons that co-rotate with Neptune’s rotation (green), and a tilt of 130° to objects that co-rotate with the ecliptic plane. Triton’s orientation is the strongest evidence that it is a captured body.WIKIMEDIA COMMONS USER ZYJACKLIN; NASA / JPL / USGS

Moons that are in retrograde orbits could not have formed from the same part of the pre-solar nebula as the planets that they orbit; that’s not consistent with the rules of how planetary systems come to be. If it couldn’t have formed alongside Neptune — the way that most moons form with their gas giant parents — then Triton must be an “adopted” moon, meaning it must have been captured at some point in the distant past.

There are two other big clues about Triton that lead us to believe it must be captured:

1. A large portion of the Neptunian system has been cleared outside of Triton; the next-nearest moon beyond it orbits more than 15 times as distant as Triton does.

2. It has the wrong density, color, and atmosphere to be a primeval moon of Neptune.

Both of these are big deals.

Densities of various bodies in the Solar System. Note the relationship between density and distance from the Sun, and the similarity of Triton to Pluto.KARIM KHAIDAROV

When we examine the moons of the other gas giants, we can see immediately why Triton is such an oddity among the large moons.

• Jupiter’s outermost large moon, Callisto, orbits at a mean distance from Jupiter of 1.9 million km. The next moon beyond that, Themisto, has a 7.4 million km distance: a 3.9-to-1 ratio.

• Saturn’s outermost big moon is Iapetus, orbiting at 3.6 million km. But Kiviuq, the next outer moon, orbits at 11.3 million km: a 3.2-to-1 ratio.

• Uranus’ outermost large moon is Oberon, with a mean orbital distance of 583,520 km. Beyond that, the next moon is Francisco, at 4.3 million km: a 7.3-to-1 ratio.

But Neptune is really weird. Not only does Triton have a mean orbital distance of just 355,000 km, but the next moon out, Nereid, orbits at 5.5 million km out (that 15.5-to-1 ratio), and the next one beyond that is a whopping 16 million km out! It’s almost like Triton’s presence cleared out the vast majority of Neptune’s outer moons, making Neptune unique among the gas giants.


The rings of Neptune, taken with Voyager 2’s wide-angle camera and

overexposed. The rings are only present in the innermost portion of the

Neptunian system; Triton is located beyond all five of them and there are no

additional rings beyond Triton. In fact, there are barely any moons beyond

Triton, too.NASA / JPL

Triton’s density is also all wrong with what we’d expect its physical properties like density, color, and atmosphere to be based on how we know objects form in the Solar System. Instead, Triton matches much better, based on these and other physical properties, with many of the Kuiper belt objects we see today. In particular, it has a frozen ice crust, a surface primarily composed of solid nitrogen, a mantle made of largely water-ice, and a large, solid core that appears to be a mix of rock and metals.

Its composition and overall color looks a lot like Pluto’s does, in fact. Here’s what Triton looked like from the photomosaic Voyager 2 took of it when it flew by back in 1989.

Global color mosaic of Triton, taken in 1989 by Voyager 2 during its flyby of

the Neptune system. Color was synthesized by combining high-resolution

images taken through orange, violet, and ultraviolet filters; these images were

displayed as red, green, and blue images and combined to create this color

version. The reddish color by the pole is thought to be a result of ultraviolet

light reacting with methane, similar to what’s now been seen on Pluto.NASA

/ JPL / USGS

Compare that with the photomosaic we took of Pluto, back in 2015, when New Horizons flew by it.

Sputnik Planitia (the left lobe of Pluto’s “heart”) is believed to be an impact basin, filled in with cryogenic ices. To the left, the reddish regions are likely hydrocarbons, responsible for Pluto’s hazes and settling down as they sink through the atmosphere and land on the surface. Pluto and Triton bear large similarities to one another in terms of a myriad of physical properties.NASA/JHUAPL/SWRI

It’s extremely similar, isn’t it? Triton, in its current location around Neptune, is a fascinating world in its own right. It has a geologically young surface, with few impact craters, much like Pluto, indicating that it’s an active world that resurfaces itself over time. We know it has geysers that erupt, sending gaseous nitrogen up and above the surface, making up most of Triton’s thin, Pluto-like atmosphere.

Two large basins can be seen here, on Triton, with relatively young surface features. The rare craters stick out like a sore


thumb, as active geology, such as flooding, melting, faulting, and collapse, resurface Triton regularly and periodically. The rough area in the middle of the central depression may correspond to the most recent eruption from the cryovolcanic ‘walled plain’ imaged here: Ruach Planitia.NASA / VOYAGER 2

Triton’s crust is 55% nitrogen ice, with other ices (like water ice and frozen carbon dioxide) mixed in: the same ratios as Pluto. Triton has a reddish color to it, thought to be from methane ice converted into tholins from ultraviolet radiation: again similar to Pluto. It even has black, smoke-emitting cryovolcanoes on its surface: evidence that perhaps a subsurface liquid ocean can force its way up through the crust. Triton, though cold and frozen, is an active world.

Triton’s south polar terrain photographed by the Voyager 2 spacecraft. About 50 dark plumes mark what are thought to be cryovolcanoes, with those trails being caused by the phenomenon colloquially called ‘black smokers.’NASA / VOYAGER 2

So how did it get to be where it is today? Like many objects that we know of originating in the Kuiper belt, Triton probably had an orbit that caused it to make a number of close passes to Neptune. When this happens today, Neptune’s gravity changes the object’s orbit in a roughly random direction. But if this happened in the early days of the Solar System, Neptune likely had a large set of masses around it, in the form of either moons, rings, or a disk.

When Triton came in, it was probably a combination of gravitational interactions, a drag force, maybe a collision, and perhaps the ejection of a binary companion that allowed Triton to become captured and circularized. Triton was likely born in the Kuiper

belt, captured early on, and the process of its capture ejected most of the outer masses and moons from the Neptunian system.

Triton, Neptune’s largest satellite, as imaged from the Voyager 2 spacecraft. The varied terrain on Triton is similar to the varied terrain we find on Pluto. Along with other similarities, we can confidently conclude that Triton originated not around Neptune itself, but in the Kuiper belt.TIME LIFE PICTURES/NASA/THE LIFE PICTURE COLLECTION/GETTY IMAGES

The result, today, is that the largest and most massive body ever to form in the Kuiper belt — 20% larger than Pluto; 29% more massive than Eris — is now Neptune’s largest moon: Triton. Today, Triton makes up 99.5% of the mass orbiting Neptune, an enormous departure from all the other giant planet systems we know of. The only explanation for its properties, especially its bizarre and unique orbit, is that Triton is a captured Kuiper belt object.

We often talk about icy moons with subsurface oceans as candidate worlds for life. We imagine large, distant, icy bodies as planets or dwarf planets in their own right. Triton was born not as a moon of Neptune, but as the largest and most massive Kuiper belt object to survive. You don’t cease to exist when you move locations, and neither did Triton. It’s the original King of the Kuiper belt, and its true origin story is a cosmic mystery that deserves to be solved.


Help Wanted

The Society continues to grow. To maintain our level of programmes and member services it takes a lot of work to organise, so the more people than can help with the various tasks will spread the load and makes it an easier job for everybody.

The Society Council recently identified various jobs that we need help with and we are looking for volunteers to join the small teams than run these functions. Please note, none of these jobs are positions on Council

If you are interested in helping out with one of the below jobs please contact Bill Thomas at [email protected] or phone 09 478 4874 or 021 225 8175 to discuss further. He will also be available at AAS meetings.

SPECIAL EVENTS COORDINATOR

This role is primarily to organise the Burbidge Dinner and also any other special events that the Society may hold. The role receives a lot of support from Council in terms of inviting speakers, venue hire etc. The Coordinator liaises with the coordinators of the astrophotography competition and writing prize but is not required to organise the judging for these awards.

OUTREACH TEAM

The Society is very active in public outreach. There are a growing number of events, particularly around the Matariki Festival, where the Society can fulfil its aim of taking astronomy to the public. Being part of the Outreach Team entails attending public events where members and the Society provide telescopes for viewing, discussing the night sky and the importance of dark skies and light pollution. This is a very satisfying team to be a part of as you really get to experience the wonder of astronomy over and over again.

SECRETARY

This role includes the recording and preparation of minutes of Council meetings.

The secretary is also responsible for the archival of Society records and documents

ASSISTANT EDITOR

We urgently need volunteers to be part of the team that prepares the Society Journal.

You will need to have access to and experience in using publishing tools such as Adobe InDesign or Microsoft Publisher

Introduction to Astronomy – Programme for 2018Date Speaker TopicMonday, February 05, 2018 Chris Benton Total Solar EclipsesMonday, March 05, 2018 John Cartwright The Northern LightsMonday, April 02, 2018 Grant Christie The First StarsMonday, May 07, 2018 Chris Benton The Hazards of Long-Duration Human SpaceflightMonday, June 04, 2018 Bernie Brenner History of Astronomy: Unsung Hereos IMonday, July 02, 2018 Bernie Brenner History of Astronomy: Unsung Hereos IIMonday, August 06, 2018 Chris Benton Water on MarsMonday, September 03, 2018 Chris Benton Gravity & Other Forces that Shape the Solar SystemMonday, October 15, 2018 Chris Benton Planetary AtmospheresMonday, November 05, 2018 Chris Benton Planetary SurfacesMonday, December 03, 2018 Chris Benton End of Year Quiz


Stardome volunteers needed

Stardome is looking for telescope volunteers!

Volunteers operate either the courtyard telescopes on Tuesday - Sunday evenings or the Zeiss telescope on Thursday- Saturday evenings. If you enjoy engaging with the public on a wide range of astronomical topics and would like to assist the Stardome team in creating an enjoyable experience for visitors, then we would love to hear from you. Volunteers gain personal satisfaction in giving the public an exciting educational experience, free admission to Stardome shows and a free Stardome shop food item every time you volunteer. Full telescope training is provided.

Please get in contact with Susan ASAP on [email protected] or 09 624 1246 ext. 207 if you’re interested.


Mars New Home ‘a Large Sandbox’from NASA

With InSight safely on the surface of Mars, the mission team at NASA’s Jet Propulsion Laboratory in Pasadena, California, is busy learning more about the spacecraft’s landing site. They knew when InSight landed on Nov. 26 that the spacecraft had touched down on target, a lava plain named Elysium Planitia. Now they’ve determined that the vehicle sits slightly tilted (about 4 degrees) in a shallow dust- and sand-filled impact crater known as a “hollow.” InSight has been engineered to operate on a surface with an inclination up to 15 degrees.

“The science team had been hoping to land in a sandy area with few rocks since we chose the landing site, so we couldn’t be happier,” said InSight project manager Tom Hoffman of JPL. “There are no landing pads or runways on Mars, so coming down in an area that is basically a large sandbox without any large rocks should make instrument deployment easier and provide a great place for our mole to start burrowing.”

Rockiness and slope grade factor into landing safety and are also important in determining whether InSight can succeed in its mission after landing. Rocks and slopes could affect InSight’s ability to place its heat-flow probe — also known as “the mole,” or HP3 — and ultra-sensitive seismometer, known as SEIS, on the surface of Mars.

Touching down on an overly steep slope in the wrong direction could also have jeopardized the spacecraft’s ability to get adequate power output from its two solar arrays, while landing beside a large rock could have prevented InSight from being able to open one of those arrays. In fact, both arrays fully deployed shortly after landing.

The InSight science team’s preliminary assessment of the photographs taken so far of the landing area suggests the area in the immediate vicinity of the lander is populated by only a few rocks. Higher-resolution images are expected to begin arriving over the coming days, after InSight releases the clear-plastic dust covers that kept the optics of the spacecraft’s two cameras safe during landing.

“We are looking forward to higher-definition pictures to confirm this preliminary assessment,” said JPL’s Bruce Banerdt, principal investigator of InSight. “If these few images — with resolution-reducing dust covers on — are accurate, it bodes well for both instrument deployment and the mole penetration of our subsurface heat-flow experiment.”

Once sites on the Martian surface have been carefully selected for the two main instruments, the team will unstow and begin initial testing of the mechanical arm that will place them there.


December 7th - 9th, 2018

Foxton Beach Bible Camp

Foxton Beach

Horowhenua

www.nzapw.org.nz

The Horowhenua Astronomical Society is hosting the sixth New Zealand Astrophotography

Weekend. Held in the lower North Island it is an annual event dedicated to astrophotography in a

wonderful dark-sky location. It is open to everyone interested in astrophotography - from beginners

to advanced. Come along and share your knowledge, tips and experiences

All sorts of astrophotography can be undertaken - solar-system/nightscapes/deep-sky

The weekend shall consist of:

• Practical astrophotography

• Image Processing

• Presentations

• Bring-and-buy

• Fish and chips dinner

• Late-night movies

Everyone is encouraged to bring along their own telescopes/binoculars/mounts/cameras etc.

however basic they might be.


The Fairy of Eagle Nebula from NASA

Image Credit: NASA, ESA, The Hubble Heritage Team, (STScI/AURA)

Explanation: The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Featured here is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars. This great pillar, which is about 7,000 light years away, will likely evaporate away in about 100,000 years. The featured image in scientifically re-assigned colors was released in 2005 as part of the fifteenth anniversary celebration of the launch of the Hubble Space Telescope.


The society has a wide variety of equipment available to rent to members. The range of scopes go from the beginner Dobsonian telescopes through to the advanced computerised GOTO systems. All rental equipment is of high quality and regularly maintained. Rental periods are typically in 4-week blocks, but other arrangements may be available if you have a specific requirement. Full training and support is given for all equipment, including advice if equipment is suitable for your needs, or experience level.

8” Astronz Dobsonian Telescope $10/week Celestron Nexstar 5 127mm SCT Alt/Az Goto Telescope $12.5/week

iOptron Minitower Alt/Az with Celestron C5 OTA $12.50/week iOptron ZEQ25 GOTO Equatorial Mount with Celestron C8 $15/week

Meade LX-10 200mm Schmidt Cassegrain $10/week Coronado PST 40mm Hydrogen-Alpha Solar Telescope $10/week

iOptron Skytracker $10/week 20x80 Binocular $7.50/week

We are often adding items to our rental equipment, and we are really keen to hear what other items may be useful to members. Any ideas of for any information regarding availability or how to rent equipment, please contact:

Curator of Instruments -Steve Hennerley on 027 2456441 orDarren Woodley on 021 776481 [email protected]


The Evening Sky in December 2018By Alan Gilmore, University of Canterbury‘s Mt John Observatory, www.canterbury.ac.nz


The brightest stars are in the east and south. Brightest of all is Sirius, due east at dusk, often twinkling

like a diamond. Higher in the southeast sky is Canopus, the second brightest star. Opposite Canopus in the north-western sky is orange Mars, the only planet in the late evening sky. Saturn, a little fainter than Mars, is low in the southwest at the beginning of the month setting two hours after the sun. It is fading into the twilight by mid-month.

The thin crescent Moon will be right of Saturn on the 9th. The first quarter Moon will be near Mars on the 15th.

Left of Sirius is the bright constellation of Orion. The line of three stars makes Orion’s belt in the classical constellation. To southern hemisphere skywatchers they make the bottom of ‘The Pot’. The faint line of stars above and right of the three is the Pot’s handle. At its centre is the Orion Nebula, a glowing gas cloud nicely seen in binoculars. Rigel, directly above the line of three stars, is a hot blue-giant star 770 light years* away. Orange Betelgeuse, below the line of three, is a cooler red-giant star 430 light years away.

Left of Orion is a triangular group making the upside down face of Taurus the bull. Orange Aldebaran is the brightest star in the V shape and makes one eye of the bull. Still further left is the Pleiades /Matariki/Subaru cluster, a tight grouping of six

naked-eye stars impressive in binoculars. It is 440 light years away.

Low in the south are the Pointers, Beta and Alpha Centauri, and Crux the Southern Cross upside down at this time of the year. In some Maori star lore the bright southern Milky Way makes the canoe of Maui with Crux being the canoe’s anchor hanging off the side. In this picture the Scorpion’s tail, just setting, can be the canoe’s prow and the Clouds of Magellan are the sails.

The Milky Way is wrapped around the horizon. The broadest part is in Sagittarius low in the west at dusk. It narrows toward Crux in the south and becomes faint in the east below Orion. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the sun is just one. The thick hub of the galaxy, 30 000 light years away, is in Sagittarius. The nearby outer edge is the faint part of the Milky Way below Orion. A scan along the Milky Way with binoculars will show many clusters of stars and a few glowing gas clouds.

The Clouds of Magellan, LMC and SMC, high in the southern sky, are two small galaxies about 160 000 and 200 000 light years away, respectively. They are easily seen by eye on a dark moonless night. The larger cloud is about 1/20th the mass of the Milky Way galaxy, the smaller cloud 1/30th but that is still many billions of stars in each.

Very low in the north is the Andromeda Galaxy seen in binoculars in a dark sky as a spindle of light. It is a bit bigger than our Milky Way galaxy and nearly three million light years away.

The bright planets are in the morning sky. Brilliant Venus rises due east around 4 a.m. at the beginning of the month; after 3:15 a.m. by the end. The moon will be left of Venus on the 2nd and below it on the 3rd. On the 22nd Jupiter and Mercury will make a close pair on the eastern horizon at dawn. Jupiter moves higher each morning while fainter Mercury sinks into the twilight.

The apparent closeness of the planets is all line-of-sight, of course. On the 22nd Mercury is 173 million km from us on our side of the Sun while Jupiter is 936 million km away on the far side of the Sun. Venus is 84 million km away.

Diary of events in December by RASNZ

December 3 Venus 3.4 degrees south of the Moon

December 5 Mercury 1.8 degrees south of the Moon

December 6 Jupiter 3.3 degrees south of the Moon

December 7 Mercury stationary

December 7 Moon new

December 7 Mars 0.0 degrees north of Neptune

December 9 Saturn 1.1 degrees south of the Moon Occn

December 9 Moon southern most declination (-21.5 degrees)

December 10 Pluto 0.7 degrees south of the Moon Occn

December 12 Moon at apogee

December 14 Neptune 2.8 degrees north of the Moon

December 15 Mars 3.4 degrees north of the Moon

December 15 Moon first quarter

December 15 Mercury greatest elong W(21)

December 18 Uranus 4.6 degrees north of the Moon

December 21 Aldebaran 1.7 degrees south of the Moon

December 21 Mercury 0.8 degrees north of Jupiter

December 21 Solstice

December 22 Moon full

December 23 Moon northern most declination (21.5 degrees)

December 23 Jupiter 5.2 degrees north of Antares

December 24 Moon at perigee

December 26 Regulus 2.4 degrees south of the Moon

December 29 Moon last quarter

DATE (NZDT) DIARY OF SOLAR SYSTEM EVENTS IN DECEMBER 2018 FOR NEW ZEALAND

T E L E S C O P E S

Astronz only stock high quality telescopes that are suitable for real astronomy, whether you are a beginner or an expert.

Our range includes Newtonian and Ritchey-Chretien type telescopes with apertures from 153mm (6”) to 406mm (16”).

people who love the night sky

A B O U T U S

Our goal is to promote astronomy in New Zealand by providing quality equipment at a reasonable price. We are owned by Auckland Astronomical Society and run by volunteers.

Astronz is unique in reinvesting everything we make back into astronomy and science education in New Zealand.

A S T R O P H O T O G R A P H Y

Get started or extend your hobby or research with our range of CCD and CMOS cameras that attach to your telescope.

We stock computerised astrophotography telescope mounts or you can even use a DSLR camera with one of our camera mounts and take great wide field astrophotographs with no telescope at all.

www.astronz.nz

[email protected]

09 473 5877

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