Big Jove not Done for the Season

By Avid planet watcher – Milan B

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?

Observe Jupiter Image
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.


Nova Newsletter – Sep/Oct 2019

Our NOVA Newsletter for Sep-Oct 2019 is available as a pdf file. An archive of older issues can be found on our Newsletter page.

Contents of Volume 2019, Issue 5, Sep-Oct 2019:

Merritt Star Quest 2019, by Suzanna Nagy

President’s Message, by Leigh Cummings

RASC Vancouver at Zajac Ranch, by Ken Jackson

Meteor Trail Radio Echoes, by Preston Thompson & William F. Wall

50-Year Anniversary of the Moon Landings, by Ted Stroman

#MeasureTheSkyBC in Sept 2019

Loss of the Night App and MeasureTheSkyBC

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.

This month, we are giving away a premium Celestron 15mm Luminos Eyepiece as main prize.

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.

Thanks go to the Merritt Astronomical Society, Starizona, and Manning Park Resort for providing prizes for this campaign.

Here are more details on using the Loss of The Night app:

Loss of the Nigh App Logo
  • Install the Loss of the Night app from the Apple App store or the Google Play store.
  • 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.
Loss of the Night app Screenshot  with direction arrow
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.

Neptune – This Week & Next

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.

Neptune Storms

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:

https://www.facebook.com/groups/326912794079774/permalink/2244082509029450/

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.

Good August Window to #MeasureTheSkyBC

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.

Here is how to participate:

Loss of the Nigh App Logo
  • Install the LOSS of the Night app from the Apple App store or the Google Play store.
  • 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.
Loss of the Night app Screenshot  with direction arrow
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.

Milky Way from Cascade Lookout at Manning Park

Plate Solving 1 -What am I looking At?

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.

Image Credit John Sanford –
https://fineartamerica.com/featured/3-cassiopeia-constellation-john-sanford.html

Now how about the image below?

T

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.

Fireflies, the Stars, and Dark Skies

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:

  1. Download the Lost of The Night app from the Apple App Store or Google Play Store 
  2. 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.
  3. 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. 

Solar Cycle 25: It’s Alive

Solar Cycle 25 is coming to life. For the second time this month, sunspots belong to Solar Cycle 25 have been identified. A sunspot, numbered AR2744, emerged in the Sun’s southern hemisphere on July 8th, 2019 and has been identified as being part of Solar Cycle 25 according to spaceweather.com.

The solar cycle is a cycle of low to high magnetic activity that the Sun goes through approximately every 11 years. The sun is currently in a period of minimum magnetic activity at the end of Solar Cycle 24. The appearance of sunspot AR2744 heralds the possible start of Solar Cycle 25.

How is AR2744 indentified as being part of Solar Cycle 25?

A key piece of evidence relies on identifying the polarity of the magnetic fields of sunspots. Sunspots generally group together in pairs to form the poles of solar magnets as if a giant horseshoe magnet was placed under the Sun’s surface.

Sunspots often come in pairs with opposite polarity as if there was a horseshoe magnetic under the solar surface. Image credit: Windows to the Universe artwork by Randy Russell using an image from NASA’s TRACE.

One sunspot of each pair has a positive (“+” or “north”) polarity where the magnetic field is directed outward. The other spot in the pair has the opposite negative polarity (“-” or “south”) where the magnetic field is directed inward. The polarity of sunspots is highlighted in magnetogram images which show the strength of magnetic fields and their polarity. The image below is a magnetogram image of the area around AR2744 where areas with “+” polarity appear as green while areas of “-” polarity appear as red/orange.

A magnetogram image of solar surface around AR2744. Credit: NASA/SDO


Sunspot pairs are usually oriented parallel to the Sun’s equator so a sunspot pair can be classified as either:

  • “+/-” as in the image above, or
  • the opposite orientation “-/+”, as if the horseshoe magnet was rotated 180 degrees.

Sunspots in the Sun’s southern hemisphere from the old Solar Cycle 24 have a -/+ polarity. AR2744 appeared in the southern hemisphere but its polarity, as seen in the above image is “+/-“, making it a part of Solar Cycle 25. This reasoning is based on G.H. Hale’s observations in the first decade of the 20th century:

  • The same polarity pattern is seen in each solar hemisphere. For example, all cycle 24 sunspots in the southern hemisphere have the same “-/+” polarity.
  • Opposite polarity pattern are seen in north vs southern hemisphere. So all cycle 24 sunspots in the northern hemisphere have “-/+” polarity.
  • Polarity patterns reverse in each subsequent solar cycle. The “-/+” polarity of cycle 24 southern spots flips to “+/-” for cycle 25.

It is common for sunspots belonging to both cycles to appear during the transition from one cycle to the next so we will have to keep an eye out for more spots belonging to cycle 25.

10 More Moons for Jupiter

Sometimes stuff gets in the way when you are looking for
faint Kuiper belt objects near the edge of the solar system. That is what happened to a team of scientists using the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory in Chile. The huge 520-megapixel camera attached to the telescope also had Jupiter in its view leading to the discovery of 10 new moons for the largest planet in the solar system.

Groupings of Jupiter’s Moons. Image Credit: CARNEGIE INSTITUTION FOR SCIENCE/ROBERTO MOLAR CANDANOSA

An additional year of observations verified the orbits of the moons and their status was confirmed by the International Astronomical Union on July 17th, 2019.

The moons are all less than 3 km in diameter and orbit Jupiter much further out than the large primary moons. The moons of Jupiter have been classified into a few groups:

  • The inner group of primary or Galilean moons (purple),
  • The prograde group that orbit Jupiter in the same direction as Jupiter’s rotation (blue), and
  • The retrograde group that orbit in the opposite direction to Jupiter’s rotation (red).

The newly discovered moons mostly fall into the above groups with 2 in the prograde group and 7 in retrograde group.

One outlier orbits in the same direction as Jupiter’s rotation but is located within the retrograde group. This outlier has tentatively been named “Valetudo” after Jupiter’s great-granddaughter. Its orbit with the retrograde group is unstable and a collision is likely at some point.

The new discovery brings Jupiter’s total up to 79 moons – the most of any planet in our solar system. Four moons of Jupiter were discovered by Galileo: Io, Europa, Ganymede, and Callisto. They are among the largest satellites in the Solar System and are easily visible in a small telescope or even binoculars (if they are supported or held steady enough).

Image of the Galilean Moons through a 100 mm refractor from Dec 2013. Image Credit: RASC Vancouver member, Ken Jackson

Jupiter is currently located about 20 degrees above the horizon, due south, at 10:00 pm PDT. Come out to Starry Nights at SFU’s Burnaby Campus on Friday, July 26th from 09:00 pm to midnight to get your own look at the Galilean moons (weather permitting) – Io slips in behind Jupiter at 09:30 pm but Europa, Ganymede, and Callisto will appear as tiny points of light with Europa on one side and Ganymede & Callisto lined up on the other side.