NOVA Newsletter for July/Aug 2020

Our NOVA Newsletter for July-Aug 2020 is available as a pdf file. An archive of older issues can be found on our Newsletter page. The contents include:

Barry Shanko 1960-2020 by Chris Gainor

Is the Sun Getting More Active? by J. Karl Miller

President’s Message by Gordon Farrell

The RASC Virtual GA and GA Lite 2020 by RASC Vancouver GA Committee

Memories of Barry by Scott McGillivray

GA and GA Lite Recordings on YouTube

Recordings of the RASC Virtual General Assembly and GA Lite sessions are being uploaded to the following playlists in the RASC Vancouver Channel on YouTube Logo.

RASC Virtual GA 2020 Playlist

(https://www.youtube.com/playlist?list=PLp4p–2i2yDC8xWhHq9Jx56jejolu9WdS)

RASC GA Lite 2020 Playlist

(https://youtu.be/O1Dv5fI9Dgc?list=PLp4p–2i2yDBtDaC6EpYVx1VNwuAltCCh)

Videos from “GA Lite – Part 1” are there now, others will be uploaded by the end of June or early July. Subscribe to the RASC Vancouver channel to get notifications when new videos are uploaded.

Happy Summer Solstice – The Earliest Since 1896

By Milan B

The (Northern) Summer Solstice, today at 2:44 PM PDT, marks the earliest beginning of summer since 1896.

Chart of Solstice dates in Vancouver classified by "type" (the remainder after dividing the year by 4). Years evenly divisible by 4 (type 0 - such as 2016, 2020, 2024) can have early solstices.
Solstice dates in Vancouver classified by “type” (the remainder after dividing the year by 4). Years evenly divisible by 4 (type 0 – such as 2016, 2020, 2024) can have early solstices.

The chart above shows how the quadrennial correction (which the Julian Calendar is solely based on) works well short term, but over a longer period of time (130 years or so), it produces a significant error (one full day). To correct this, the Gregorian Calendar introduces another correction which is to omit leap days in some of the years that centuries begin with (or end, some would say). Years like 1700, 1800, 1900, 2100, 2200, 2300 etc. are chosen for this correction. So, we are in a deep stretch without this centennial correction and the seasons’ start dates will be falling even earlier until late 21st century.

Comet C/2017 T2 near Galaxy M109

Our observing director, Robert Conrad, wrote this post on facebook about comet C/2017 T2 (PANSTARRS).

“Don’t miss the opportunity on the night of June 15th to see comet C/2017 T2 (PANSTARRS) in the same FOV as the bright galaxy Messier 109 and the bright star Gamma Ursa Majoris. View it around 11:00pm when it’s dark and still relatively high in the sky. Good luck! “

The good news is that the comet is still close to M109 on the night of Tuesday June 16th, 2020 and the skies are forecasted to be somewhat clear in Vancouver. It is easy to find in the North-Western skies because of its proximity to Phecda – a bright star in the bowl of the Big Dipper. Recent observations have the comet at magnitude 8.5 so it is visible in small telescopes.

Galaxy M109 next to the Bowl of the Big Dipper at 11:00 pm PDT on June 16th, 2020 from Vancouver
Comet C/2017 T2 (PANSTARRS) is within 1° of Galaxy M109

GA Lite Astronomy Webinars

Join us for our “GA Lite” series of astronomy webinars, a great follow-up to the RASC Virtual General Assembly. The series is scheduled over the two weekends June 13&14  and June 20&21, with more details at

ga2020.rasc-vancouver/schedule-galiteh

The webinars are free, open to the public, and family friendly.

What else are you going to do with this Vancouver weather forecast?

Barry Shanko Recognized with 2020 RASC President’s Award

Long-time RASC Vancouver member, Barry Shanko, received the President’s Award as announced at the 2020 RASC AGM this afternoon. A hand out of the 2020 RASC awards winners is available but information about the President’s Award is available in the following excerpt.

President’s Award

This award is given at the President’s discretion, usually once a year, to a member (or members) who has/have made an important contribution to the Society.

Mr. Shanko served as speaker coordinator for the Vancouver Centre for 31 years and was active in RASC public outreach efforts in the Vancouver area. In his life he had to overcome many economic and health challenges but became known for his ability to attract outstanding speakers from around Canada and the U.S. for Vancouver Centre events. Unfortunately, Mr. Shanko passed away unexpectedly just before his 60th birthday on 2020 May 2.

RASC Board of Directors Statement on Racial Inequality

The Board of Directors of the Royal Astronomical Society of Canada met recently, and unanimously approved the following statement:

In response to recent events, The Royal Astronomical Society of Canada wishes to state that it supports peaceful protests and dialogue across the world aimed at addressing longstanding issues of racial inequality, and in particular anti-Black discrimination and violence. The Society is dedicated to equality of opportunity and treatment for all, regardless of race, sex, gender identity or expression, sexual orientation, national or ethnic origin, religion or religious belief, age, marital status, and disabilities. We are opposed to all forms of unlawful and unfair discrimination.

Inferior Conjunction of Venus – June 2020

by Venus Observer, Milan B.

In two days (June 3rd, 2020), our twin sister planet will pass between us and the Sun. This brings fond memories of the similar passes in June 2004 and June 2012, which both resulted in transits across the solar disk, but this time around, Venus will just miss the solar disk by a quarter of a degree on its passage from northern to southern ecliptic latitudes.

Conjunction of Venus with the Sun on June 3rd, 2020, courtesy of Sky Safari

This 8 year cycle of Venus was known even to ancient Mayas. In 8 Earths years, Venus will make 13 orbits around the Sun and since both planets orbit the sun in the same direction, there will be 13 – 8 = 5 synodic periods of Venus looking from planet Earth. Any Fibonacci fans out there?

During 5 synodic periods Venus will go through 5 inferior conjunctions. Only one of these five is close to the Sun in the current epoque, two will be midway to the maximum distance which is just under 9 degrees and the remaining two will be very close to the maximum angular distance from the Sun.

5 synodic periods of Venus actually falls short of 8 years by 2 and a half days. With this, all inferior conjunctions will slowly move earlier in the year within each series. The 2020 conjunction, happening on June 3rd, is part of the June-May series, as was the 2004 transit, which occurred on June 8th and the 2012 transit, which occurred on June 5th.

With this years conjunction being a near miss, the question becomes: when will Venus next be so close to the solar disk? The visualisation below shows about 130 years of inferior conjunctions and each of the five seasons is labelled by the pair of months that it occurs in during the 21st century.

130 Years of Inferior Conjunction of Venus with the Sun, courtesy of Milan B. and Tableau

As the Jun-May series conjunctions (the green series above) are slowly moving away from the Sun and will not result in any transits for many centuries, we will need to turn to another series to bring us the next sequence of close passes and transits. The Jan-Dec series conjunctions, which are currently far from the solar disk are slowly inching (in astronomical terms) towards the Sun and also regressing from mid January (in early 2000’s) into early December (in the early 2100’s) which will result in another pair of transits, this time the December transits of 2117 and 2125.

Venus one week after the 2015 Inferior Conjunction, Aug 22nd 2015, courtesy of Milan B. and SkyWatcher.

From the chart above it becomes apparent that after the June 2020 conjunction, Venus will not venture so close to the Sun (from Earths perspective) for another 97 years, until the 2117 transit. Hopefully, some of the younger generations will get a chance to see this remarkable astronomical event.

Drake’s Birthday, Seager, Roddenberry & the Odds for Extraterrestrial Life


Frank Drake is 90 years old today (May 28, 2020), making it a good day to ponder the odds for extraterrestrial life. Drake, an astrophysicist, has been involved in the search for extraterrestrial intelligence, including the founding of SETI, for decades. One of his best-known contributions was the development of the Drake Equation in 1961. The equation was originally intended to promote discussion between Drake and his colleagues on extraterrestrial life. The equation is still alive and relevant today with new revisions being proposed, debates on the values for its parameters, and a continuing appreciation of it from the general public. On the occasion of Frank Drake’s birthday, here is the Drake Equation plus two others inspired by it.

The Drake Equation estimates the number of communicating civilizations in the cosmos or more simply, the odds of finding intelligent life. The equation calculates the number of communicating civilizations by multiplying together estimates of several parameters. SETI’s web page displays the Drake equation as:

Where

  • N = The number of civilizations in the Milky Way Galaxy whose electromagnetic emissions are detectable.
  • R* = The rate of formation of stars suitable for the development of intelligent life. 
  • fp = The fraction of those stars with planetary systems.
  • ne = The number of planets, per solar system, with an environment suitable for life.
  • fl = The fraction of suitable planets on which life actually appears.
  • fi = The fraction of life-bearing planets on which intelligent life emerges.
  • fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.
  • L = The length of time such civilizations release detectable signals into space.

A wide range of values have been proposed for each parameter but a modern optimistic estimate has

R=7, fp= 90%,  ne= 0.3,  fl =10%,  fi = 1.0%, fc = 1.0%, L = 10,000,000

which yields N = 189 civilizations in our galaxy.

The Drake Equation provides an estimate of the number of civilizations whose electromagnetic emissions are detectable. Astronomer Sara Seager proposed an equation that based on detecting planets whose biosignature gases can be detected. Biosignature gases, produced by living organisms, accumulate in a planet’s atmosphere to levels that can be detected with a remote space telescope. The Seager equation is:

N =  N*  FQ  FHZ FO  FL  FS

Where 

  • N = the number of planets with detectable biosignature gases 
  • N* = number of M stars with I < 13 
  • FQ = fraction of quiet M stars 
  • FHZ = fraction with rocky planets in the HZ 
  • FO = fraction of observable=transiting systems observable with JWST 
  • FL = fraction with life 
  • FS = fraction with detectable spectroscopic signatures

Seager’s estimates for these parameters for M stars in the TESS/JWST survey are

N* = 30000,  (FQ FHZ) = 0.15, FO = 0.001, FL = 1.0, FS = 0.5

Which yields N = 2 civilizations.

Sara Seager is giving an “Update on NASA’s TESS Exoplanet Mission” at the RASC Virtual General Assembly. Live streamed on Sunday June 7th, 2020 on the RASC YouTube channel www.youtube.com/c/rascanada.

Sara Seager posted a YouTube video honouring Drake and the influence he had on her own research.

A form of Drake’s equation was used by Gene Roddenberry to pitch Star Trek in 1964. Roddenberry was trying to justify the large number of inhabited planets in the show. He did not have a copy of the equation so he made up his own variant

with no explanation of the parameters. It is said that Frank Drake later pointed out to Roddenberry that a value raised to the first power is merely the value itself when he visited the Star Trek set.

Happy 90th Birthday to Frank Drake, a pioneer in the search for life elsewhere in the universe.