President’s Message – May 2022

Posted by as President's Message

Every year, the Victoria Centre of the Royal Astronomical Society of Canada sponsors two awards at the Vancouver Island Regional Science Fair. Well, not every year – we missed the last two years because of covid. This year, the Science Fair was virtual and about one quarter the size of the pre-covid event – 52 projects – with 6 assessed to be on astronomical or astronomy-adjacent themes. Many thanks to our representatives, Dorothy Paul and David Lee, for interviewing the students and arriving at their decisions. Each winner received a recognition certificate, a RASC family membership (for the student and one adult), a copy of Explore the Universe, and the offer of a classroom visit from our Schools Programs officers. We also invited the prize winners to present their projects at the Astro Café.

Nathan Hellner-Mestelman and Beata Ariana-Minniti
Nathan Hellner-Mestelman and Beata Ariana-Minniti

Grade 7 student Beata Ariana-Minniti created a very clever solar heat collector, coupled to a battery charger. Nathan Hellner-Mestelman (Grade 9) worked out the optimal orbit for cube-sats to avoid chain-reaction collisions. These students wowed us with their presentations at the Astro Café. Nathan was included in Team Vancouver Island at the Canada-Wide Science Fair and went on to win a silver medal.

As this year of Astro Cafés come to a close, we should all thank Joe Carr and Chris Purse for getting us through the fully online times and the transition to hybrid meetings. We have grown closer, despite the isolation of the last couple of years, because of their efforts. We’ll see you again at Astro Café starting in September. It is essential that we get more people to step up to help continue the Astro Café.

I want to congratulate our strong community who pulled together to put on all the facets that went into International Astronomy Day on May 7. We did not have much time to organize, as we did not even know if there would be in-person events until March. David Lee and Laurie Roche coordinated our volunteers wonderfully. There are others among you who are perfectly capable and I hope willing to take on their roles for future events. Astronomy outreach is very satisfying. Let’s share the load in making these opportunities happen.

The amateur astronomy community in Victoria is strong. Our club is extremely fortunate to have sufficient funds to make fund-raising unnecessary and sufficient volunteers to put on several high quality events. We are not lacking a strong Board and Council. Nevertheless, some members are not joining in, I think because they have not imagined that their contribution would be valuable and fun. Let me assure you that indeed you will get more out of such volunteerism than you put in.

Look Up,
Randy Enkin (email)

Total Lunar Eclipse – May 15/16, 2022

Posted by as Observing Highlights

On Sunday, May 15th, 2022, we will be able to view a total eclipse of the Moon (weather permitting) from Southern Vancouver Island, British Columbia, Canada. The Moon will be in full eclipse after rising from the southeastern horizon, remaining fully eclipsed for about an hour before transitioning into a partial phase as it climbs in altitude and moves to the south. The Lunar Eclipse will end just before midnight.

Enlarge this video to view details for the Lunar Eclipse timing and phases. Depiction of this particular Lunar Eclipse is as viewed from Victoria – generated by Starry Night Pro Plus 8 and captured using Snagit 2022.

This is a perfect opportunity to visually observe this beautiful celestial event, and possibly capture some photographs from a location with an unobstructed view to the east and south.

Total Eclipse Begins8:29PM
Moon Rises8:42PM – probably visible 10-15 mins later
Greatest Eclipse9:12PM
Total Eclipse Ends9:54PM
Partial Eclipse Ends11:51PM
Above Eclipse times are for Pacific Daylight Time (PDT) for the west coast of North America, and are calculated from UT as presented in the Observers Handbook 2022, pages 127-131.
Lunar Eclipse diagram – NASA

What’s Happening

A total lunar eclipse occurs when the Earth comes between the Sun and the Moon. During a lunar eclipse the Moon’s position traverses the Earth’s shadow. The Moon’s first contact with the Earth’s shadow is at the outer band of the shadow called the penumbra. The light falling on the Moon is progressively blocked until at the moment of total eclipse the Moon is completely in the darkest central area of the Earth’s shadow called the umbra. At the point of total eclipse the process starts to reverse itself until the Moon is totally out of the Earth’s shadow.


Glossary

  • limb – the outer edge of the Moon
  • penumbra – the outer band of the Earth’s shadow
  • umbra – the darker central area of the Earth’s shadow
  • partial eclipse – the Moon is positioned within the penumbra
  • total eclipse – the Moon is positioned totally within the umbra

Observing Tips

What do you need?

Everything from your eyes, binoculars and telescope are suitable. Bear in mind this is a long process, so dress warmly and bring a chair if you want to be comfortable.

Find yourself a location that has a clear horizon view to the east and south especially if you wish to view the early fully-eclipsed stage. Observing from a hill will help you spot the rising Moon earlier than if you observe from lower elevations or sea level.

Keep a log of what you see and note the time. Pay attention to how much of the light on the moon is obscured and if there are any colouration changes. During the total eclipse the Moon will take on a deep orange-red colour. The colour of the Moon is a function of contaminants in the atmosphere and varies from year to year.

A good observing project for this long-lasting eclipse will be to observe the craters on the Moon as the eclipse progresses. Craters will be immersed and emerge from the Earth’s shadow on the Moon at times specified in the Observers Handbook 2022, page 131.

2019 Total Lunar Eclipse from Victoria – composite photo by Joe Carr

Photographic Tips

Equipment

Any camera with the capability of setting shutter speeds and aperture settings manually will do fine. The ability to use interchangeable lenses will be an advantage for more detailed images of the Moon. For the darker parts of the eclipse, eg. totality you should use a tripod support for best results. If you have access to a telescope you can try capturing the event using prime focus techniques through the telescope optics.

Settings

Today’s digital cameras are very sensitive to light reflected by the Moon. Use ISO 400 to ISO 800 and a long telephoto lens or zoom setting. Smartphones and point-and-shoot digital cameras will not produce rewarding photos of the eclipsed Moon, but can be useful for taking panoramic shots of your surroundings which include the eclipsed Moon.

Technique for smartphone cameras

Smartphone cameras typically do not support manual settings, so using them to capture a lunar eclipse will be less rewarding than using more capable cameras. That said, smartphone cameras can be held up to a telescope eyepiece to capture an image of the Moon. Aligning the tiny lens to the eyepiece can be tricky, however there are platforms made to clamp onto an eyepiece barrel which will hold smartphones steady enough to take acceptable photos of the Moon, including the eclipsed Moon.

Technique for interchangeable lens cameras

The simplest eclipse pictures can be taken with manual settings on your camera and a normal lens, preferably supported by a tripod. For best results use a cable release to minimize vibration. Images taken in this fashion result in a small lunar image. This is why it is preferable to use a telephoto lens to photograph the Moon.

For a full frame camera try a 200mm lens or even better, a 500mm lens or higher. You may also use teleconverters to increase magnification, these typically come in 1.4x and 2x strengths. Their downside is they reduce the effective aperture of your optical system. A 1.4x teleconverter will decrease your effective exposure by 1 stop, a 2x teleconverter will decrease your effective exposure by 2 stops. Work out your effective aperture of your optical system ahead of time so you don’t have to think about it on the night of the eclipse.

Note for the smaller sub-full frame sensors of some digital cameras you gain an extra advantage as the focal length of the lens is effectively magnified by a factor. For example a Nikon DX body your 200mm lens would be effectively 300mm.

  • APS-C Nikon DX, Pentax : 1.5x
  • APS-C Canon EF-S : 1.6x
  • Four Thirds : 2x

Example:

 Focal Length ApertureEffective Focal Length
with 2x teleconvertor
Effective Aperture
with 2x teleconvertor
 180mm 2.8 360mm 5.6
 480mm 6.8 960mm 13.6

To achieve any higher magnification than what is stated above you will have to use a telescope at prime focus. For this your manual camera does need to have the capability of using interchangeable lenses. For prime focus you will use the telescope optics as your interchangeable lens. To attach your camera to your telescope you will need two things a T-adapter that fits your camera and a telescope camera adapter that fits your telescope.

The telescope camera adapter is designed to fit in the focusing tube of your telescope and is threaded to accept the T-adapter of your camera. With the magnification involved with telescopic optics it is likely that you will need to use a tracking mount. Preferably the mount should be able to track at lunar speed as opposed to sidereal but if the shutter speeds chosen are shorter than 1 or 2 minutes this is not critical.

Exposure times are the next consideration. The following exposure times are based on a medium ISO setting and an effective aperture that would be common with a long telephoto and teleconverter combination. Exposures may vary with your equipment based on ISO speed and effective aperture. The Danjon Lunar Eclipse Luminosity Scale has been included to provide better guesstimates for totality.

Exposure Times: based on ISO 400
Full Moon1/500 second at f/16
1st Contact1/250 second at f/16 see note 1.
2nd Contact1 second at f/16 see note 2.
Totality
*see table below
L = 4 : 4 seconds at f16  L = 3: 15 seconds at f16  L = 2: 1 minute at f16  L = 1: 4 minutes at f16
3rd Contact1 second at f/16 see note 2.
4th Contact1/250 second at f/16 see note 1.
* Danjon Lunar Eclipse Luminosity Scale
 L = 1dark eclipse; lunar surface details distinguishable only with difficultly
 L = 2deep red or rust coloured eclipse; central part of the umbra dark but outer rim relatively bright
 L = 3brick-red eclipse; usually with a brighter (frequently yellow) rim to the umbra
 L = 4very bright copper-red or orange eclipse, with a bluish, very bright umbral rim

Note 1. 1st and 4th contact times given for the partial phases are biased for the light part of the Moon. Remember you are dealing with vastly different exposures between the light and dark parts of the Moon during eclipse. The bias of about 1 stop minus avoids overexposure of the dominant bright area of the Moon.

Note 2. 2nd and 3rd contact times given for the partial phases are biased for the dark part of the Moon. The bias of about 1 stop plus is a good strategy for negative film not quite so good for slides and digital capture given they don’t tolerate overexposure well.

The exposure times are only recommendations. Remember the cardinal rule about photography … bracket. Always try exposures plus and minus your chosen exposure. This gives you a better chance at getting usable results. Let’s all hope for clear weather. If you have any questions please send email to David Lee at davidflee7331@gmail.com.


David Lee – original text
Joe Carr – updated for 2022
Brenda Stuart – illustrations


More information:

President’s Message – Mar 2022

Posted by as President's Message

What is it that links our community together? Every year, we recognize a few members of the Victoria Centre and present them awards of appreciation and excellence. We announced the recipients at the Annual General Meeting. I had the pleasure last week of driving around Victoria handing out their framed certificates. I enjoyed seeing these stellar members of our community in their home settings. It is one of the great privileges of being president. Everyone was proud and delighted, and often surprised at the recognition. We are far greater than the sum of our parts. These members have gone an extra length to make our community stronger and more active. Thank-you!

Awardees (clockwise from top left): John McDonald, Chris Purse, Alec Lee, Bruce Lane, Barbara Lane, Cameron Burton.

We have a wide range of backgrounds and interests. We spend our time with a variety of aspects spanning the range of amateur astronomy. I particularly like the feeling of connection with people around the world and throughout time. Some are interested to produce the best image of an astronomical object. Some are keen to know their way around the constellations.

There is a huge hunger for astronomical knowledge out there in the bigger public. This was made very clear this last week with front page articles and television features about our friend and astro- buddy Sid Sidhu; on the occasion of having an asteroid named after him. Sid has been central to our public outreach and society in- reach activities over a period of decades!

What is it that links our community together is that the wonders of the sky fill us with awe and with pleasure.

Look Up,
Randy Enkin (email)

President’s Message – Feb 2022

Posted by as President's Message

Randy Enkin

A colleague recently told me that my family name, Enkin, in Japanese literally means “near-far” (遠近). One sense of the Japanese word “enkin” is “perspective”; another is “bifocal glasses”. My colleague flatteringly suggested that if we could get some of our other colleagues to spend time wearing Enkin glasses, we could probably quickly achieve consensus regarding a scientific controversy that we have been involved in for the last 30 years.

One of the joys of astronomy is using our knowledge of what is near to help us understand what is far. For me, my training as a geologist gives me a fair amount of knowledge concerning how the earth works and this informs my way at looking at astronomical objects. In my Astro Café presentations, I try to help the rest of you to see my perspective on various astronomical topics.

Everybody in the Victoria Centre has something important to contribute. You all have your personal interests and experiences, which informs what you see and understand in our common interest of astronomy. It would be wonderful to hear more of you at the Astro Café. I am quite sure our wonderful SkyNews editor would love to receive more articles for this newsletter! Presentations do not have to be polished, nor original. Your perspective is what we value. In my experience, I see that we are a particularly patient and accepting audience.

So, put on some Enkin glasses. Take joy in what you see and share it with our community. We will all learn to see your subject with a new perspective, and we will gain a better appreciation of each other.
Thank you all for accepting and supporting me through my first year as President of the Victoria Centre. It is an honour to be part of this long-running institution. I look forward to year two, with lots more activities – sometimes even in person! I look forward to getting to know more of you and sharing our mutual appreciation of the wonders of the sky.

Look Up,
Randy Enkin, President@Victoria.RASC.ca

President’s Message – Jan 2022

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Betelgeuse winked two years ago. The bright red shoulder star of Orion became noticeably dimmer and then recovered over a number of months. I prepared a presentation on this red giant for our Astro Cafe (2020-01-27) and included a note about how some other cultures explain the phenomenon:

Randy Enkin using his sextant
Randy Enkin using his sextant

“Orion represents Nyeeruna, who creates fire-magic in his right hand, represented by Betelgeuse, to reach the Yugarilya sisters (the Pleiades). The eldest sister, Kambugudha, symbolized by the Hyades cluster, kicks sand in his face, dispelling his magic, and stops him from gaining access to the sisters. The process is described as cyclic, with Betelgeuse brightening and fading over time. The Pemon people in Brazil called Orion Zililkawai and the constellation represented a man whose wife cut off his leg. Betelgeuse’s variable brightness was associated with the cutting of the limb.”

Last weekend, the Royal Astronomical Society of Canada Vice President, Charles Ennis, gave a wonderful presentation at the FDAO Star Party on the RASC’s World Asterisms Project. His compilation includes 455 asterisms that include stars found in the region of the constellation Orion! At least 455 cultures from every corner of the world have looked up at the sky and were inspired to describe this same view with a story.

Charles Ennis’ presenting at FDAO Star Party

We amateur astronomers are part of this connection between all people over space and time. The sky continues to delight and fascinate us. We share our stories, and invent new ones. We look up.

I am so pleased to share the love of the sky with you. The earth has almost traveled a complete orbit around the sun since you have asked me to be the president of the Victoria Centre. Thank you for your support and trust in me. I look forward to the next orbit!

Look Up,
Randy Enkin, President@Victoria.RASC.ca

President’s Message – Dec 2021

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Ah 2021. What a strange trip around the Sun! I am writing this letter on the day of the winter solstice. There is a waning gibbous moon shining high in the east, when I go to bed, and it is high in the west to greet me in the morning. I take great solace in watching and thinking about the dependable motion of the Earth through the Universe, while so much of life and news this year has left me feeling unsettled.

Randy Enkin using his sextant
Randy Enkin using his sextant

Nearly as dependable as the astronomical objects has been you, our astronomical community. I am so pleased when I see the 30 or 40 of us gather each Monday evening at our virtual Astro Café. We are an appreciative and supportive community. Look at all the different skill sets and experiences that get shared every week. And look at those beautiful photos and sketches that we have created. I particularly wish to mention the personal observatories (I know of 3!) that are getting designed and built by members of our centre, as well as the fantastic work by our technical committee in upgrading the Victoria Centre Observatory.

Our group has motivated me to try new astro-projects – whether observing sunspots with a solar telescope borrowed from the Centre (thanks to the capable curation of our telescope collection by Sid Sidhu), or star hopping to those faint fuzzies that you deep space observers like. And I love the expressions of appreciation when I show off my lunar sketches to our crowd.

Do remember that our community survives on the strength of our volunteerism. We have a specific requirement this year for a new secretary and a new vice president. Don’t feel you aren’t up to the job! I still feel like a newbie in the role of president, but there is no shortage of good council from the many past executives who continue to be active. Come join us on the inside, and you will feel even more affection for the Centre.

I wish us all a fruitful and fulfilling new year, with many clear skies.

Look Up,
Randy Enkin, President@Victoria.RASC.ca

President’s Message – Nov 2021

Posted by as President's Message

Everybody should have a good astro-project on the go. My current one concerns the timing of lunar eclipses.

Solar eclipse geography and timing is known with remarkable precision. So much so that people, including many members of our RASC community, are willing to plan long, difficult, and expensive trips to watch them. The timing and location of the earth’s shadow, or umbra, across the Moon during a lunar eclipse is much more variable and poorly understood.

I was delighted to learn that as far back as 1687, Philippe de la Hire published that the Earth’s shadow was larger than could be accounted for by an airless Earth, leading to lunar eclipses that start a few minutes earlier and end a few minutes later than expected. This was important work, because observing the timing of eclipses was, in principle, one way to measure longitude – as long as the expected timing was well established.

Moon on Dallas Road, Oct 8, 2021, by Randy Enkin

The problem arises from the complex nature of the earth’s atmosphere that obscures, diffracts and refracts the sun’s light on its way to the Moon. I first became aware of the role of amateur lunar crater eclipse timing just before the eclipse last May (which was clouded out), and I am certainly keen to try again on the upcoming lunar eclipse, starting around 23:19 PST on Thursday, November 18. If there are clear skies, I’ll be out with my telescope, noting the time to the tenth of a minute that the earth’s umbra darkens (“immersion”) and then departs (“emersion”) from various lunar craters. Sky and Telescope has been compiling these observations since 1956. Herald and Sinnott (2014) have analysed the compilation, extended back to 1842, with an amazing 22 539 observations. Their main conclusion is that the Earth is surrounded by a “notional eclipse-forming layer” that is 87km thick. It is a really surprising result, since even noctilucent clouds don’t show up that high in the atmosphere.

Herald and Sinnott point out that amateur uninstrumented observations provide continuity with the early observations in their compilation and provide insight into the visual response of the human eye. To help with the observations, Thursday- Friday November 18-19, I have annotated a picture of the full moon with the crater timings predicted by Fred Espenak. I hope some of you will join me making these simple but useful observations.

Look Up,
Randy Enkin, President@Victoria.RASC.ca

President’s Message – October 2021

Posted by as President's Message

Questions, Answers, and Questions

Randy Enkin using his sextant
Randy Enkin using his sextant

One satisfaction of astronomy is the sense of continuity with astronomers from all over the world and spanning the decades, centuries, and millennia. The wonders of the sky fill us with awe and provoke so many questions. I appreciate the multidisciplinary approach to answering these questions.

Today’s anecdote concerns an article published this week, with 25 authors from 5 countries. The Chinese Chang’e 5 probe brought back to Earth the first lunar samples in 4 decades. They targeted a place on the Moon that was suspected of being young, due to the region’s low density of craters. Galileo observed craters on the moon 400 years ago, but it was only in the 1960s that meteor impacts were confirmed to be the dominant mechanism of their origin.

The observational and theoretical development of celestial mechanics, universal gravitation, the solar nebula, and planetary accretion were all required to understand dating planetary surfaces, by measuring the size and number of craters. We also needed telescopes, rockets, robotics, petrology, geochemistry, and geochronology to complement the study. The Moon is the only planetary body where impact crater ages have been calibrated with radiometric dating, but there had been no samples so far measured that are between 3.2 and 0.8 billion years old. The new samples were dated at 1.96±.06 billion years, sitting in the middle of that gap and forcing a revision of the current crater dating method. The new date is very young for the Moon’s surface and brings up new questions, like why the Moon was still melting crust so recently.

Back-scattered electron (BSE) images and false color energy dispersive spectroscopy (EDS) element maps of the two fragments from the Chang’e 5 sample
Back-scattered electron (BSE) images and false color energy dispersive spectroscopy (EDS) element maps of the two fragments from the Chang’e 5 sample

I’m filled with a sense of connection with my fellow humans who can conceive of such questions, work on them from many different aspects over the centuries, answer some, and end up with even more questions. And I look up at the sky with happiness.

Look Up,
Randy Enkin email

President’s Message – September 2021

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Carolyn Shoemaker
Carolyn Shoemaker (Nature)

Carolyn Shoemaker died last month. After her children had grown up and she was 51 years old, she started her astronomy career. She helped establish the Palomar Asteroid and Comet Survey, and for decades she studied the photographic plates coming off of the 18 inch Schmidt wide-field telescope, located in a dome next to the Palomar 200 inch telescope. At an average of 1 discovery for every 100 hours spent at the stereoscopic microscope, she became the world’s top comet finder.

This was more than a job. Everybody who knew her emphasizes her enthusiasm and humour. Among these friends is an acquaintance of several of our centre members, David Levy. On March 23, 1993, David passed some photographs he had just taken of the region near Jupiter, and Carolyn exclaimed that she saw in these images a strange “squashed” comet. This comet became known as Shoemaker-Levy-9. It was actually the 11th comet they had discovered together, but two were aperiodic and so had a different naming convention. I remember the excitement, when 4 months later, 21 fragments of SL9 crashed into Jupiter with images from professionals and amateurs alike started pouring in. We got to watch a cosmic collision in real time!

What kept Carolyn Shoemaker at this slow, painstaking task was similar to what many amateur astronomers feel. She said “The thrill of discovery is deeply satisfying”. Few of us will get the opportunity to do cutting edge science with the best instruments available, but all of us get our own personal thrills. Whether the discovery is at the eyepiece, or on the computer monitor, or from a revelation that comes during a talk at our Astro Cafe, the experience continues to be deeply satisfying. In memory of Carolyn Shoemaker, I wish you all many more of these deeply satisfying moments!

Look Up,
Randy Enkin, President email

President’s Message – August 2021

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I’ve had a couple of requests this summer to help friends who have never seen Saturn through a telescope with their own eyes before. One of them was lent the wonderful 1970s Tasco 60mm refractor that I bought off Reg Dunkley, at our Astro Cafe exchange, way back when we could meet in person. Reg says this telescope kindled his interest in astronomy years ago, so it is fun to give this equipment to another enthusiastic newbie. The other request is from Toronto and I’m getting a RASC Toronto Centre loaner scope ready, for when I’m there next week. We do indeed belong to a great society that gives us these opportunities.

Saturn – by Brock Johnston

But what is it about seeing the beautiful objects in the sky ourselves? There are much better images available on the internet. Nothing we can see from Earth compares to the pictures of our sixth planet sent by the Voyager and Cassini spacecraft. Saturn especially has been something that has turned on people from all walks of life to the delights of the night sky. Indeed, the design specifications for the “Galileo-scope” included the possibility to see the rings of Saturn, because they knew that that view is the gateway to spending more time with a telescope (I have one, and it works!).

Saturn is certainly other- worldly. It is beautiful in its form and symmetry. The physics which produce the rings are non-intuitive. It is a challenge to see it, but not an unreasonable challenge for most. But there must be more.

Each time I take my telescope out, I fall in love again with the universe we live in. Even when I am alone, I sometimes swoon out loud. I don’t know why, but I sure am glad I get to share the feeling with my astro-friends. As our friend Diane Bell told us: “the sky is a gift!”

Enjoy the sky. Share it.
Look Up,
Randy Enkin, President email