AstroNotes October 2019

Editor’s Message . Ottawa Skies . An Interview With David Levy . Astrophotography . Book Review . Estelle's Pick of the Month . Submitted Images . Monthly Challenge Objects . Announcements . Carp Star Parties . FLO Star Parties . Next Meeting . Centre Information

Volume: 

58

Number: 

9

Pages: 

28

Download PDF version: 

AstroNotes

The Newsletter of the Ottawa Centre, RASC

Volume 58 – No. 9 – October 2019

Editor’s Message

In case you haven’t heard yet, Paul Sadler is stepping down as our Carp Star Party Coordinator. Paul has been doing this job for several years now and has brought many positive changes to this highly visible public outreach event. He
improved the parking arrangement making it much safer for all concerned as well as reducing the annoyance factor when people leave early. Fewer headlights in your eyes. Paul also had the clever idea of having portable toilets available for members and guest convenience. The first year he even paid for it himself!

The other thing that Paul did was to set up a system of marshals. For each star party there was a marshal to ensure that everything ran smoothly. Like any good leader, he spread the load so nobody was over-burdened thus ensuring that even if he could not be there, somebody was always there to make sure the event ran smoothly. On behalf of the entire membership of Ottawa Centre and the star gazing public, I would like to express our sincere thanks to Paul for his  service. It is people like Paul that make the Ottawa Centre such a great thing to be part of. Thank you very much Paul.

Our Annual Dinner Meeting is coming up on November 15 th . Our guest speaker will be Dr. John Moores, Associate Professor and York Research Chair in Space Exploration at York University. His topic will be Our Solar System: A Planetary Rosetta Stone. See the information in the article below for more details.

Over the past year we have had people asking where they can learn more about sketching what they are observing. So Brian McCullough has put together a workshop that he is offering, free, on Saturday, October 26. More information can be found in the Announcement section.

Clear Skies,
Gordon astronotes@ottawa.rasc.ca


An Interview With David Levy

By: Gary Boyle

Astronomy is a wonderful and pleasing hobby that many have enjoyed for years and even decades. As we escape our light domed cities and suburbs for starry landscapes, the night sky is ours to behold. We love to share the wonders of the night whenever possible whether pointing out constellations to new sky watchers or showing celestial objects, the planets or the moon through our telescopes. We all have our own experiences of sharing, educating and motivating others but David Levy has taken the passion of the night to an all-time high.

I have known David since I joined the Montreal Centre of the RASC in 1976. From the start, his enthusiasm for astronomy was evident as he was an active member of the Society as well as a nature instructor at Green Acres children’s camp located north of Montreal where he introduced astronomy. Born in Montreal in 1948, David became interested in astronomy at a very early age. By 1966 he had started his serious search for comets. Keeping detailed notes David logged a total of 917 hours and 27 minutes before his first discovery on the night of November 13, 1984, of Comet Levy-Rudenko. It was a co-discovery but still it was a new find. Since that fateful night, David has gone on to discover or co-
discover more than 20 comets including the greatest discovery of all, Comet Shoemaker-Levy 9 and its impact with the planet Jupiter in 1994.

David’s father loved Shakespeare and this was also one of David’s interests. Literature and poetry encouraged David to pursue his bachelor’s and master’s degrees in English literature. His passion for the night sky is quite evident in the more than 30 books he has written up to now including the biographies of Clyde Tombaugh and Bart Bok. His most recent book is his autobiography entitled “A Nightwatchman’s Journey – The Road Not Taken”. This tell-all book gives a  personal account of his decades of observations and discoveries as well as his very personal health issues such as depression, asthma and cancer.

David was on a book tour that included Montreal and Kingston and thanks to the efforts of the Ottawa Centre he was invited to attend our Centre meeting on September 6, 2019. The last segment of the meeting was dedicated to a  personal one on one sit down interview between David and me in front of an audience of 121 people. Over the next half-hour, I asked specific questions about the book including the all-important discovery of Comet Shoemaker-Levy 9. He  also spoke of his attempted suicide. For the last few minutes, the audience was able to ask questions. When asked what helped David through his bouts of depression, he replied; “it was the love of astronomy that helped through these difficult times”.

Book sales were a great success as all 24 pre-ordered books from National Office were sold. David was busy before and after the meeting signing books and posing for pictures with people. I highly recommend purchasing this book and reading David’s numerous accomplishments and how one person can overcome major health problems and dark periods of their life and strive ahead with determination to follow their dreams.


Astrophotography

Getting Started in Astro-imaging

By: Paul Klauninger

Autumn is upon us and there’s no better time to take that first plunge into astrophotography that you’ve been contemplating. The Fall is my favorite time of year for observing and imaging. The nights are longer than in the summer, they’re cool, but generally not cold, and there are far fewer pesky bugs around to disturb one’s astronomical explorations. Celestially, the many wonders inhabiting the Milky Way are prominent at our latitude early in the evening, followed by the galaxies of Pegasus and Andromeda, and then a glimpse at winter’s sky gems treats us before dawn’s light. So, if you’ve thought about trying your hand at astro-imaging and you have some basic photographic gear, this article offers a primer on getting started.

Astro-imaging comprises different levels of complexity (and expense!), ranging from the pleasantly simple to the absurdly complex. While it is tempting to succumb to the flashy magazine and internet ads featuring high-power telescopes and expensive cameras, that’s not really the best way to get started. Even though creating beautiful images of nebulae and galaxies has certainly become far easier than it was back in the film and pre-GOTO days, it still tends to be a complex and time-consuming process. Imaging at that level needs to become a labour of love to avoid expensive gear languishing unused in a closet somewhere, and that takes time to learn.

On the other hand, starting out with gear that many of us already have for daytime terrestrial photography is a great way to get into imaging the night sky and to find out if it is a pursuit that calls to you (and your pocketbook) for a deeper commitment. Wide-angle imaging allows you to capture large areas of the sky and is the best for shooting subjects such as the Milky Way, meteor showers, and auroras. It also lets you create some neat time lapse movies of such subjects as the night progresses. So, to that end, the list of equipment is pretty straightforward.

  • You need a camera with a wide-angle lens that allows you to manually set image parameters such as exposure time, lens aperture, and ISO speed. Today’s DSLR and mirrorless cameras made by companies like Canon, Nikon, Sony, and others, are the most suitable. These are available at prices ranging from entry level to professional grade and offer a wide array of interchangeable lenses.
  • You’ll need a lens with a short focal length, preferably in the 8 to 35 mm range. Many DSLR cameras sold as a kit typically include a lens in this range. Note that cellphone and pocket point-and- shoot cameras are not really up to the task, for a variety of technical reasons.
  • You’ll also need a stable tripod and a ballhead mount to aim the camera.
  • Some type of shutter release is also required in order to take an exposure without having to physically touch the camera. This avoids any jostling that would blur the image. Inexpensive after- market intervalometers are  available for many makes of camera and are the best for this purpose. They are also a must-have for doing time lapse sequences, unless your camera has a built-in capability to do these.
  • Finally, you’ll also likely need something to combat the evening dew that is very common in our climate, especially during spring and autumn nights. Lens dew shields help, but usually only for a limited while. Heated lens dew straps and their controllers are commercially available and do a fine job. Some folks even get away with using short blasts from 12-volt camping hair blowers on their lens ... just don’t drain your car battery while out in the middle of nowhere! You can also try wrapping inexpensive hand warmer packets around the top of your lens. These can give off a useful amount of heat for several hours.

Now that you’ve got your equipment together, get to know how to operate your camera in the fully manual mode. Practise this before making the trip out to a dark sky site so that you won’t waste precious clear skies and imaging time trying to figure it all out. As is the case for most astrophotography, you’ll want to set up under an open and dark rural sky, preferably on a moonless night. Sites such as our Fred Lossing Observatory or the Lennox-Addington
dark sky preserve are ideal, as are many favorite camping grounds such as Algonquin Park or Bon Echo. Once you’re on site and have set up your equipment, you have to focus the camera. This is not as easy as
it sounds, since you have to do it manually and in the dark! Don’t rush this step. Poor focusing ruins more pictures than any other factor.

When you’re happy with the focus, aim your camera at the scene you want, being careful not to disturb the focus, otherwise you’ll have to repeat that procedure. The next step is then to figure out just how long of an exposure you need. This depends on a number of factors, primarily, the actual darkness of the sky, where in the sky you are pointed, and the maximum aperture f-ratio of your lens. Since you are not using a mount that will keep your camera pointed at a fixed position in the sky, you only have a very limited amount of time in an exposure before the Earth’s rotation causes the stars to become noticeable streaks. While star trails are neat to shoot on their own accord, most of the time you’ll want stars that, well, look like round stars!

To keep your exposures as short as possible, use a high ISO setting (1600 to 6400) and the widest angle lens that you have. The shorter the lens focal length is, the wider the field of view you’ll capture and the longer you can expose without obvious star trailing. My favorite nightscape lens is a Bower 16mm, and with a maximum aperture setting of F2.0, it is also optically a fairly “fast” lens. All images in this article were taken with that lens. Where in the sky you’re pointed also affects your maximum non-trailing exposure length. Pointing to the north (typical for auroras) lets you shoot longer than when pointing south, since the stars closer to Polaris appear to move through much less sky during the night than their more southerly counterparts.

Take some test shots of your scene at different exposure lengths and review them on your camera screen to find the most pleasing view. Note that virtually all images taken on a stationary tripod will show some trailing when you zoom in, but since you tend to view the entire image when looking at a nightscape scene, short trailing will not be very obvious, up to a certain point. You want to determine where that point is.

These full-height crops of the Milky Way show how increasing the exposure length brings out progressively more subtle detail, but also increases obvious star trailing and creates brighter sky backgrounds. So how much exposure is too much? If your camera displays a histogram for your images when you review them, you can also use that to help determine whether your image is under- or over-exposed.

The histogram is a graphical view of the brightness range within an image. The horizontal axis represents the variation in brightness, with the darkest pixels to the left and the lightest pixels to the right. The height of the columns represents the relative number of pixels at a particular brightness value, so the higher the column, the more numerous are the pixels at that value. Typically for astro-images, you’ll see a peak in the pixel distribution towards the left side of the graph. This tells you that most of the pixels tend to be fairly dark, with fewer light pixels, as you would expect. The histograms shown here tell you that the 15-second image is under-exposed, since the peak is slammed up hard to the left side of the graph, with its left half (the darkest pixels) “clipped” off. On the other hand, the 60-second shot is over-exposed, with its peak being much wider and positioned in the centre of the graph. The 30-second histogram is the type of pixel distribution that you want. For the test shots I took for this article, I settled on an exposure length of 25 seconds at ISO 3200 as the best compromise between capturing Milky Way details and minimizing star trailing.
And with a bit of basic image processing that I’ll cover in a follow-up article, this was my final result ... a single exposure of the Milky Way taken with a Canon 60Da DSLR and 16mm lens on a stationary tripod.

Finally, when you’ve got your equipment setup and exposure times all working properly, consider taking a sequence of shots (200 or more) over the course of a few hours. You can later stitch these together and create a time lapse video of what you saw that night. This can be especially cool when you’re taking pictures of an auroral display or a meteor shower, and if you’re lucky, you might just catch that brilliant fireball that lit up one of your shots as though it was daytime!

Good luck with your shooting and clear skies!


Book Review

Solar Observer’s Handbook – A Guide to Beginners, Charles Ennis, RASC, 2017

A Review by Patrick Brewer

This recently published RASC guidebook seems very timely considering that there is a transit of Mercury coming up this November 11 th . The next transit will not be until 2032. Charles Ennis has written a basic introductory book about the Sun and solar observing. There are descriptions of observing methods from inexpensive to expensive. He provides us with a number of tips and techniques. He starts by telling us why we should observe the Sun and then follows this with a general explanation of how the Sun works and descriptions of the different regions of the solar atmosphere. The rest of the book is devoted to observing and starts appropriately enough with an explanation of the
dangers of solar observing and how to do so safely. The author spends several pages describing the various solar filter types available and their advantages and disadvantages. In particular, he spends some time describing the operation of the etalon filter as used in the popular Meade/Coronado PST.

The next chapter deals with solar weather, such as sunspots, and solar flares. Subsequent chapters cover eclipses and transits, record keeping, solar photography, solar radio astronomy, and aurorae. Although the book covers all of these topics, they are only covered briefly, with most chapters only a couple of pages long. However, the book is only intended as a beginner’s guide and once you become more experienced there are certainly larger and more detailed books on the subject. This book though is a good starting point for an exploration of the nearest star.

My only significant problem with the book is the reproduction quality of the photographs of telescopes and other observing equipment. They are not printed using the usual halftone process. They look as if they were copied on a photocopy machine and the result is a soft, muddy reproduction where significant detail is lost. The line diagrams on the other hand are fine, as are generally the photographs of the Sun. The number and selection of photographs and diagrams in the book is good, it’s just the reproduction that is a problem.

The book concludes with a list of solar observing and astrophysics websites, a glossary, and an index. The Solar Observer’s Handbook is available directly from the RASC for $17.95 or can be borrowed for
free from the Ottawa Centre library.


Estelle's Pick of the Month


Announcements

Annual Dinner Meeting

The RASC Ottawa Centre Annual Dinner Meeting is coming up fast. It is being held Friday November 15 which is less than three weeks away now. For $48.00 dollars you get a great buffet dinner, the wonderful company of your astronomical friends, a fabulous lecture, and even a chance to win some prizes! Algonquin College is hosting us once again at the Woodroffe Ave Campus with meet, mingle and drinks starting at 6:00 PM and dinner at 7:00.

Tickets will be available in person at the upcoming RASC monthly meeting the Friday Nov 1 at the Aviation Museum, payment by cash or credit card. They are also available by email from stephen@snourse.ca, payment by e-transfer or cash at pickup at the door. Please note, ticket sales will close Thursday night, Nov 7 as we have to give our final meal numbers to Algonquin the next day. There will be no walk-up tickets for sale at the dinner meeting.

Dinner Speaker: Dr. John E. Moores, York University Associate Professor and York Research Chair in Space Exploration
Topic: Our Solar System: A Planetary Rosetta Stone

The past 25 years have seen a revolution in our understanding of where planets may be found and how many are out there. In that time we have discovered thousands of new planets and now believe that, on average, there is a planet for every star in the sky. Yet we know most of the planets beyond our own solar system as little more than wiggles and bumps on a graph. Just like the Rosetta Stone allowed us to translate ancient Egyptian hieroglyphics, it is our exploration of our own solar system which will allow us to translate those bumps and wiggles into the language of rock and ice, oceans and storms. Only then can we truly know those planets as worlds in their own right.

Bio:

I am an Associate Professor in the Department of Earth and Space Science and Engineering and hold the York Research Chair in Space Exploration at York University (with a graduate appointment in the Earth and Space Science and Physics and Astronomy Departments). I am a member of the Royal Society of Canada's College of New Scholars, Artists and Scientists as well as a Participating Scientist on the Mars Science Laboratory (MSL) Mission, popularly known as the Curiosity Rover. After training on MER in 2004, I contributed to the 2005 Huygens Mission to Saturn's Moon Titan and the 2008 Phoenix Mission to the Martian Arctic and currently serve on the InSight, MSL and Juno missions in various capacities.

My work has been included in 65 peer-reviewed papers and 152 conference proceedings. I am the Director of the Technologies for Exo/Planetary Science NSERC CREATE Program, a member of the Canadian Space Agency's Planetary Exploration Consultation Committee, the Canadian Meteorological and Oceanographic Society's Scientific Committee and a York University Senator. I am currently developing planetary simulation facilities at York University as part of the Planetary Volatile Laboratory and am supporting Surface Operations on the Mars Science Laboratory Rover. Previously, I have led experimental studies into interactions of volatiles with the martian surface and polar caps. I have also participated in the development of the Surface Stereo Imager for the Phoenix Lander and have been involved in several conceptual space mission design studies, instrument development activities and analogue planetary missions.

Tickets Available at the November meetings and by email from Stephen Nourse, stephen@snourse.ca

Carp Star Parties

Paul Sadler and his team continue to work hard to be sure the Public Star Parties run smoothly. They have been doing a great job and getting good turn outs. If you haven’t been to one lately, grab your scope and join them. You are bound to have a good time. As always, these are weather dependent and subject to change.

Saturday May 25 th – Star Party at the Carp Public Library / Diefenbunker
Rain Date - Friday May 31 st
Saturday June 22 nd – Star Party at the Carp Public Library / Diefenbunker
Rain Date - Friday June 28 th A Success!
Saturday July 27 th – Star Party at the Carp Public Library / Diefenbunker - Yes but...
Rain Date - Friday August 2 nd - Much better night
Saturday August 24 th – Star Party at the Carp Public Library / Diefenbunker
Rain Date - Friday August 30 th Another success!
Saturday September 21 st – Star Party at the Carp Public Library / Diefenbunker - I hear this one got rave reviews!!
Friday October 18 th – Star Party at the Carp Public Library / Diefenbunker
No Rain Date

Other Dates of Interest

Saturday October 5 th – International Astronomy Day (Fall) at the Canada Aviation and Space Museum, part of World Space Week.

FLO Star Party Dates for 2019

Our Ottawa Centre’s Members’ Star Parties at the FLO will continue this summer. If you haven’t attended before, be sure to mark at least one of these dates on your calendar. You are welcome to bring family members or a guest.

SUMMER & FALL DATES
May 4 – New Moon
Good turn-out, great night
June 1 – Waning Crescent Moon, 3.8% illumination No Go
July 6 – Waxing Crescent Moon, 19.7% illumination, sets 11:53P.M. NO GO
August 3 – Waxing Crescent Moon, 2 days old, sets 9:51 P.M. – moved to August 4 th Good
turnout
August 31 – Waxing Crescent Moon, 2.4% illumination - Family Day BBQ, Great turn out
Sept 28 – New Moon - No Go
October 26 – Waning Crescent Moon, 3.5% illumination
November 24 -Waning Crescent Moon, 5.3% illumination

Next Meeting

7:30 PM Friday October 4, 2019 at the Canada Aviation and Space Museum (directions). Note there is a $4.00 parking fee for museum parking. The meeting runs until 9:30 pm PLUS: all our regular meeting features: Ottawa Skies, 10-minute Astronomy News Update, Observation Reports and, of course, the beloved Door Prizes!

All RASC monthly meetings are free and open to members and non-members alike. Refreshments will be available, and this will be a wonderful opportunity to meet new friends who share a common interest
and chat in a relaxed, stimulating and fun environment. Please join us!

Centre Information

To subscribe (or unsubscribe) to our members-only discussion list (rascottawa@googlegroups.com ) please contact secretary@ottawa.rasc.ca .

The Ottawa Centre 2018 Council

President: Mike Moghadam (president@ottawa.rasc.ca)
Vice President: Stephen Nourse
Secretary: Chris Teron (secretary@ottawa.rasc.ca)
Treasurer: Oscar Echeverri (treasurer@ottawa.rasc.ca)
Centre Meeting Chair: Oscar Echeverri (meetingchair@ottawa.rasc.ca)
Councillors: Carmen Rush, Gerry Shewan, Jim Sofia
National Council Representatives: Karen Finstad, Ingrid de Buda
Past President: Tim Cole

2018 Appointed Positions

Membership: Art Fraser
Star Parties: Paul Sadler
Fred Lossing Observatory: Rick Scholes (flo@ottawa.rasc.ca)
Light Pollution Abatement: OPEN
Public Outreach Coordinator: OPEN
Hospitality: Art & Anne Fraser
Stan Mott Astronomy Library: Estelle Rother
Ted Bean Telescope Library: Darren Weatherall
Webmaster: Mick Wilson (webmaster@ottawa.rasc.ca)
AstroNotes Editors: Gordon Webster & Douglas Fleming (astronotes@ottawa.rasc.ca)