The RASC Vancouver Centre is hosting the RASC 2020 General Assembly! We are planning an exciting series of talks, presentations, speakers, and public outreach activities.
The 2020 GA will be held from Friday, June 5 to Sunday, June 7 at the Executive Plaza Hotel & Conference Centre in Coquitlam B.C. The public Helen Sawyer Hogg lecture will take place at Simon Fraser University, with an opportunity to visit the Trottier Observatory afterwards.
Help us make the 2020 General Assembly in Vancouver our best one yet! Please take a moment and fill out a survey to help Vancouver Centre estimate attendance to the 2020 GA. https://tiny.cc/GA2020Survey
Your survey response will help the GA planning committee, and will not be made public.
Linda and Tom Spilker explored the Solar System together during their work at the Jet Propulsion Laboratory. See them at our Oct meeting where they will be talking about their work along with recent updates.
Date: Thursday Oct 10th at 7:30 pm Location: Room C 9001 in the Chemistry Building, Simon Fraser University (just off of the south-west corner of the Academic Quadrangle).
Topic 1: Cassini’s Intriguing New Discoveries by Dr. Linda Spilker
Dr. Linda Spilker, Cassini Project Scientist, will present updates of the highlights of Cassini’s 13-year mission of discovery at Saturn. Since the end of Cassini’s mission scientists have been teasing out new information about Saturn, the rings and moons from the huge stock of data collected during the mission. Some of the most surprising results were discovered during the final orbits of the mission, diving through the gap between the rings and Saturn for the very first time.
Speaker #2: Architecting Space Missions by Dr. Tom Spilker
Since establishing my consulting business I have worked with multiple NASA centers, such as JPL, Goddard Research Center, Glenn Research Center, and Langley Research Center, multiple universities, and private corporations and companies, on a variety of space flight mission concepts and instrument concepts. Straying somewhat (but not entirely!) from the science missions, recently I have architected a large, rotating space station for the Gateway Foundation and its operating arm, Orbital Assembly Corp. Among other important functions, that space station should make it much easier to implement planetary science missions, trips to the moon, and large telescopes in space.
As it gets closer to a new Moon, Sept 20th and into the first week of October are great dates to help with our #MeasureTheSkyBC campaign to measure light pollution and it is your last opportunity to get a chance to win a prize – including a premium eyepiece!
It’s easy – all you need is your phone & your eyes!
Last Month, TK & CD from Kitsilano won by using the Loss of the Night app on 11 stars at Cascade Look Out in Manning Park. They reported their limiting magnitude was greater than 5 from that site.
We are also giving away a copy of the RASC book “Explore the Universe Guide” and free registration to the Cascade Star Gazer’s Package at Manning Park’s Astronomy Weekend, on October 18-20 & 25-27, 2019.
To get a chance to win a prize, send an email to [email protected] with your location and experience with measuring the sky, include the date/time and limiting magnitude from the Loss of the Night app if possible.
Start the app and enter some basic user information in the user data section such as your age, whether you wear glasses/contacts, and your observing experience.
Go outside on a clear night. Try to pick a location where you can see a large part of the sky and that is away from bright lights. Ideally, pick a time after 10:00 pm when the sun is well below the horizon (after the end of astronomical twilight).
Follow the instructions in the app to start measuring stars.
Follow the arrow to find a target star.
Using the app is a fun, video-game like experience – great for kids. It works by helping you find target stars and then asking if the star is visible with your eyes. There is a demo mode so you can even try it out during the day. The app does not need internet (after it is installed) so you can use it when camping or out at a remote location.
Start by aiming your phone/tablet at the sky. The app displays a star field over-laid with a circle and an arrow.
Move your phone/tablet in the direction of the arrow. Go slowly and turn your whole body as necessary to follow the arrow.
Is the target star visible with your eyes?
When you locate the target star, a large orange circle is displayed, a smaller flashing yellow circle appears around the target star, and the display freezes.
Now you can lower your phone/tablet and look to see if the target star is visible with your eyes. Finish with this target by clicking the appropriate button.
Repeat on 8 target stars to get a good measure of the light pollution at your location. Expect some target stars to be easily visible, some barely visible, and some not visible, as the app tries to narrow down what you can see at your location.
After you’ve finished your measurement, the app will display your “limiting magnitude” which can be used as a measure of light pollution. Your data can be sent anonymously to a global database of light pollution measurements. You can see your measurement on a map, track changes over time, and compare it to other observations from around the world at http://www.myskyatnight.com.
Don’t forget to send an email to [email protected] for a chance to win a prize – please include the date/time, your location and limiting magnitude in the email if possible.
It’s mid September. It’s been more than 3 months since Jupiter reached opposition in early June. It was a memorable summer for many Jupiter observers like myself despite fewer than usual clear summer nights and the lower than usual position of Jupiter for northern observers.
As Big Jove is heading towards the deep winter sleep, barely hanging in the southwestern sky after the sunset, one may ask: when will this apparition of Jupiter end, isn’t it almost over?
Brilliant Jupiter or Big Jove currently appears low in the southwestern sky just after sunset.
Image credit: National Geographic Magazine.
Well, it’s true that the big gas giant lies very low in the sky, waiting for the fast approaching Sun to catch up from the west, but the season finale is being delayed by an unexpected gift from the Sun itself.
After spending nearly six months decorating the northern hemisphere our local star is quickly descending towards the Celestial Equator and then into the Southern Hemisphere taking with it a big chink of daylight for northern mid-latitude observers, almost 4 minutes every day. The depletion of the daylight hours is especially visible in the evenings — only in the month of September does the sunset times shift by more than one hour (earlier in the day) for observers at 49° North.
The Sun is moving eastward throughout the year, while Jupiter switched from retrograde (westward) to direct (eastward) motion around the 11th of August as it started galloping through the southern zodiac constellations. This results in Jupiter setting times (which are occurring earlier each day) slightly delayed compared to the stationary stars. For stars (which rise and set) the difference between two consecutive star-rises or star-sets is about 4 minutes – the difference between the solar day and the sidereal day on Earth.
For Jupiter this difference is already much lower than 4 minutes for all of September and it is being further reduced as Jupiter is heading towards the superior conjunction with the Sun in December this year. However, the solar contribution to this delay (the pace of the shortening of the daylight hours) will decay slowly as we enter the autumn months and will completely stop at Winter Solstice.
The peak of this unusual delay will be in the period between October 3rd and October 9th as shown in the table below. During this week we will lose only 9 minutes of potential observing time for Jupiter.
Table 1) A combination of Jupiter’s accelerating eastward motion in the sky and the rapid descent of the Sun in northern skies results in extending this year’s Jupiter observing season by a few weeks.
Jupiter will be visible for at least another two months, sinking ever lower in the SW sky, before the Solar System’s largest planet gets lost in the December twilight. So, please go out and enjoy the big Jove’s apparition while it lasts.
Could celestial geometry arrange a completely opposite phenomenon from the one mentioned above? Stay tuned for the accelerated season ending of the brightest star in the sky – Sirius. It will happen, you might have guessed, exactly six months from now.
Robert Conrad, our Observing Chair, posted on Facebook about a close conjunction of Neptune with the 4.2 magnitude star Phi Aquarii in Aquarius. The pair will be less than 15 arc-seconds apart on Thursday, Sept 6th – that is about a third of Jupiter’s apparent size at opposition – so the pair will appear practically on top of each other.
The Great Dark Spot of Neptune at the top accompanied by “Dark Spot 2” further south. Image credit: NASA/Voyager 2 Team
But then just after midnight on Monday, Sept 9th (technically, it will be Tuesday at 00:07:12 am), Neptune reaches opposition when it is directly opposite the Sun as viewed from the Earth. Neptune will have moved slightly to the west of Phi Aquarii by then but is still close – within 10 arc=minutes.
If you haven’t seen Neptune then this is a great opportunity. Neptune is not visible to the naked-eye as its magnitude of 7.8 is well past the limit for naked-eye observations. You may get a glimpse of it using steady-supported binoculars but a 200x view through a 150 mm or larger telescope is required to resolve it into a disk. Either way, the 4.2 magnitude star Phi Aquarii is a good guide. AAVSO charts are on Robert’s post at:
Even better is to observe Neptune over several nights and notice its motion relative to Phi Aquarii. Neptune’s orbital period of 164.6 years makes it move slowly across the sky, it will still be together with Phi Aquarri in a one degree field of view on Oct 1st, 2019.
Recording the relative positions over several nights lets you avoids Galileo’s missed opportunity – there is evidence that Galileo observed Neptune on January 6th, 1613, and again on January 27, 1613 and noted a slight discrepancy in its position versus the background stars. However, there is no record that he made further observations and he likely thought it to be a fixed blue star rather than a planet.
Credit for Neptune’s discovery goes to Britain’s John Couch Adams and France’s Urbain Le Verrier who had worked out the position of a theoreticl 8th planet independently based on perturbations in the observed orbit of Uranus. Le Verrier’s analysis predicted the new planet’s location to with one degree of where it was observed by J. G. Galle and H. L. d’Arrest, staff astronomers at the Berlin Observatory, in 1846.
Neptune is a gas giant, like its near twin Uranus: it has more mass than Uranus but is slightly smaller because its greater mass cause more gravitational compression of its atmosphere. The methane in Neptune’s upper atmosphere absorbs the red light from the Sun but reflects the blue light from the Sun back into space. This is why Neptune appears blue. Neptune has the strongest winds of any planet in our solar system with wind speeds reaching 2,000 km/h, three time stronger than Jupiter’s. It has several large dark spots with the largest known as the Great Dark Spot – similar to the hurricane-like storms and the Great Red Spot on Jupiter.
Looking for Stars with the Loss of the Night App. Image credit: Christopher Kyba, CC BY-NC 4.0
August 22nd to 31st are great dates to help with our #MeasureTheSkyBC campaign to measure light pollution.
It’s easy – all you need is your phone & your eyes!
And… get a chance to win a prize by sending us an email at [email protected] that you did it. This month, we are giving away a copy of the RASC book “Explore the Universe Guide” and free registration to the Lightning Lake Star Gazer’s Package at Manning Park’s Dark Sky Astronomy Weekend, on October 18-20 & 25-27, 2019.
Start the app and enter some basic user information in the user data section such as your age, whether you wear glasses/contacts, and your observing experience.
Go outside on a clear night. Try to pick a location where you can see a large part of the sky and that is away from bright lights. Ideally, pick a time after 10:00 pm when the sun is well below the horizon (after the end of astronomical twilight).
Follow the instructions in the app to start measuring stars.
Follow the arrow to find a target star.
Using the app is a fun, video-game like experience – great for kids. It works by helping you find target stars and then asking if the star is visible with your eyes. There is a demo mode so you can even try it out during the day. The app does not need internet (after it is installed) so you can use it when camping or out at a remote location.
Start by aiming your phone/tablet at the sky. The app displays a star field over-laid with a circle and an arrow.
Move your phone/tablet in the direction of the arrow. Go slowly and turn your whole body as necessary to follow the arrow.
Is the target star visible with your eyes?
When you locate the target star, a large orange circle is displayed, a smaller flashing yellow circle appears around the target star, and the display freezes.
Now you can lower your phone/tablet and look to see if the target star is visible with your eyes. Finish with this target by clicking the appropriate button.
Repeat on 8 target stars to get a good measure of the light pollution at your location. Expect some target stars to be easily visible, some barely visible, and some not visible, as the app tries to narrow down what you can see at your location.
After you’ve finished your measurement, the app will display your “limiting magnitude” which can be used as a measure of light pollution. Your data can be sent anonymously to a global database of light pollution measurements. You can see your measurement on a map, track changes over time, and compare it to other observations from around the world at http://www.myskyatnight.com.
Don’t forget to send an email to [email protected] for a chance to win a prize – please include your location and limiting magnitude in the email if possible.
If you are familiar with the constellations then you will quickly recognize the distinctive W-pattern in the image below and identify it as an image of the constellation Cassiopeia.
This one is harder to identify but some amazing software software has become more accessible to amateur astronomers in the last few years that makes identifying images a breeze. Plate Solving software uses pattern matching techniques to match an image of the sky with star catalogs to determine the stars and other objects that appear in the image.
The popular web app plate solver, Astrometry.net ( http://nova.astrometry.net/), can be used without installing any software – just upload an image and after a few minutes Astrometry.net displays results like the following.
It is a bit of a jumble of overlapping star labels but near the center you can see that the Messier cluster M103 has been identified.
Astrometry.net also displays a wider view of the area around the image and the deep-key objects that it found in the image. In this case, we can see that the image is an area near Casseopeia that contains M103.
The term “Plate Solving” is historical and refers to the large photographic glass plates that were used prior to the development of photographic film. Plates continued to be used in astronomy until the 1990s because they were superior to film for research-quality imaging – they were extremely stable and less likely to bend or distort.
Plate solving did not originate with the advent of computers, it was done manually by humans and often by women. The Harvard Computers were a team of women whose work included classifying stars by comparing the photographs to known catalogs. Many significant scientific contributions were made by these women’s subsequent analysis, classification, and processing of the astronomical data in the plates:
Annie Jump Cannon developed a stellar classification system using the strength of absorption lines and categorized stars into the now-familiar spectral classes O, B, A, F, G, K, M,
Antonia Maury discerned in the spectra a way to assess the relative sizes of stars, and
Henrietta Leavitt showed how the cyclic changes of certain variable stars could serve as distance markers in space.
Plate solving software is available in other package in addition to Astrometry.net and a follow-up article will cover other packages and the uses of plate solving by amateur astronomers.
The flashes of fireflies on a warm summer night create enchanting light shows. Fireflies exist on every continent, in North America they are most common in Eastern Canada and the United States. Ten species of fireflies in five genera have been recorded in British Columbia but adults of only two species produce flashed bioluminescent signals. Fireflies have captured the human imagination for centuries and have frequently been the focus of art, literature, and cultural traditions.
A jungle full of fireflies, few trees like this were really filled up with hundreds of fireflies in small area. They displayed a synchronized light pattern a mating time where males put up the light show to attract females. The moonlit forest added the fill light while the stars in background completed the frame to witness this most dramatic scene – Credit: Abhijit Juvekarf, Malshej, Ghat, India.7 Jun 2014.
Here come real stars to fill the upper skies, And here on earth come emulating flies, That though they never equal stars in size, (And they were never really stars at heart) Achieve at times a very star-like start. Only, of course, they can’t sustain the part.
Fireflies in the Garden by Robert Frost
This year’s World Firefly Day was on July 6-7, 2019 and the theme this year was “Fireflies need dark nights.” There is growing evidence that suggests light pollution contributes to the decline of firefly populations across the globe. Fireflies emit light to attract males, communicate, and defend territory. Scientists have found that light pollution reduces flashing activities in a fireflies.
The most important step to take to protect nocturnal species like fireflies from light pollution is to follow responsible lighting practices that reduce or eliminate unnecessary outdoor lighting. You can also fight light pollution by helping #MeasureTheSkyBC with you smart phone or tablet:
Measure the sky glow at your location using the app on a night when the Moon is below the horizon – the dates Aug 22 – Aug 31 around the next new Moon are a great time to make measurements.
Submit your measurement and send an email to [email protected] for a chance to win prizes.
Another cultural connection between fireflies and space is the 2002-2003 TV serfies “Firefly” that follows the the adventures of the renegade crew of Serenity, a “Firefly-class” spaceship.
