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.

Celebrate the 50th Anniversary of the Apollo 11 Landing

Join us for a gathering with light snacks, door prizes, moon talks and short films followed by observing Jupiter and Saturn at the Trottier Observatory.

Saturday, July 20, 2019, 7:30 PM to Midnight

  • Celebration and Talks: 07:30pm to 10:00pm in Room SWH 10081 (Saywell Hall). Limited to 150 people.
  • Observing at the Trottier Observatory: 10:00pm to midnight (weather permitting)

Simon Fraser University, Burnaby Campus – find us on a map

Meetup.com logo

RSVP and View the event on meetup

Admittance to the observatory is on a first-come, first-served basis. For a summary of our Observatory House Rules and Starry Night Etiquette, please visit:  

http://www.sfu.ca/science/alumni-community/trottierobservatory/starrynights.html

Speakers: Ted Stroman and Leigh Cummings

Abstract: On October 4th, 1957, the USSR launched the first successful orbital satellite into space. By the end of the 1960s, only 13 years later, the USA successfully landed 2 men on the Moon. Ted Stroman is an expert on the history of the Apollo program that brought that to be. Leigh Cummings has been trying to keep up with the developments in the effort to return to the Moon by the next decade. We hope to give an entertaining and eye-opening picture of where and how we have been to the Moon and where and how we might go on.

One of the interesting Apollo facts you will learn at the talk is that the first Apollo 11 “feet” to touch the Moon were Canadian! The four landing gear system “legs” (or “struts”) on the Apollo Lunar Module descent stages were built by the Canadian company  Heroux-Devtek, based in Quebec. These landing legs were constructed of a light-weight aluminum and compressible honeycomb design to aid in shock absorption.

The first Apollo 11 feet to actually touch the surface of the moon – were made in Montreal. Image credit: NASA

Neil Armstrong landed so gently that the legs did not compress on impact leaving the Lunar Module’s ladder positioned quite high above the surface.

Join us on July 20th to learn more.

High Tides during the Eclipse

A visitor to our Canada Day table noticed that the tide seem very low in False Creek and wondered if it had any connection to the Total Solar Eclipse on July 2nd in South America.

The answer is yes. A solar eclipse must happen at new Moon when the the Moon is lined up directly between the Sun and the Earth.

Image Credit: Penn State Astronomy & Astrophysics

Tides are mostly caused by the gravity of the Moon as it pulls the water on the near-side away from the Earth and pulls the Earth away from the water on the far side. With the Sun aligned with the Moon during an eclipse – the Sun is also pulling in the same direction and so the tides are larger.

Total solar eclipses are awesome events to see but not that special for tides. The same alignment and high tides occur at every new Moon regardless of whether or not there is an eclipse. Such high tides have been give the name “spring tide” (technically, spring tides also include the high tides that occur when the Moon is full)..

Other factors cause the highest tides which are colloquially known as “King Tides”. The orbit of the Moon around the Earth, and the Earth around the Sun are not perfectly circular and tides are larger when

  • The Moon is closest to the Earth – the Moon is at perigee
  • The Earth is closest to the Sun – the Earth is at perihelion

Back in Sept 2015, the above factors plus others combined to give extreme tides that will not be matched again until 2034! Read more about the Extreme Tides September 28 in 2015.

Solar Minimum Ha Fun on Canada Day

You might think there is not much to see on the Sun as experts predict a long, deep solar minimum in 2019. But you can try to prove them wrong by observing the sun at the Canada Day celebration in Maple Ridge‘s Memorial Peace Park from 12 pm to 6 pm on Monday, July 1st, 2019.

RASC Vancouver will have several special hydrogen-alpha (Ha) telescopes setup for the public to safely observe solar features such as flares, prominences, sunspots, and filaments. Hydrogen-alpha (Ha) telescopes use special filters that block almost all the light from the sun except for a narrow band of red light emitted when hydrogen is energized in sun’s chromosphere. Many think that Ha’s greatest highlights are the prominences shot out from the sun’s limb, and large prominences can occur even during a solar minimum.

If the weather and the sun cooperate then you will be able to see some on Canada Day. In the the mean time, take a look at the pictures below, taken by amateur astronomers, to see what solar features can look like in Ha.

Full Disc Image with Prominences and Filaments from June 4th 2019 . Image Credit:
https://www.cloudynights.com/user/219375-rickv/
Fountain Prominence Animation on May 18th, 2019. Image Credit: http://www.astrobin.com/users/rigel123/
Active Region AR2741 from May 15th, 2019. Image Credit:
https://www.cloudynights.com/user/256858-malveaux/
Large Solar Prominence from Coquitlam on Oct 16th, 2018. Image Credit: Ken Jackson

Five Tidbits for Asteroid Day

Asteroid Day events are scheduled during the week of 30 June, the date of the largest asteroid impact of Earth in recorded history (Tunguska). Asteroid Day promotes awareness and provides knowledge to the general public about the importance of asteroids in the formation of our universe and the role they play in our solar system today. Asteroid Day TV started streaming on June 27th at 4am PDT.

Below are some tidbits about asteroids to help celebrate the day.

An Asteroid with a Comet-Like Tail

Observations from December and early January show that Asteroid (6478) Gault has developed a comet-like tail.  This small asteroid is spining so fast that it is throwing off material from its surface.

Double Tail of Asteroid 6478 Gault. Image credit: NASA Goddard Space Flight Center from Greenbelt, MD, USA [CC BY 2.0 ]

Observe Asteroid 18 Melpomene at Opposition

Asteroid 18 Melpomene is currently well placed for observation, located in the constellation Scutum. It is at opposition on July 2nd 2019 and will reach its highest point 31° above the southern horizon around 1 am PDT. It will be visible in small telescopes as its visual magnitude is 9.2

Asteroid 17 Melpomene at Opposition on July 2nd, 2019. Image credit: theskylive.com

Asteroid Re-named as a Tribute to Brian Eno

Astronomers renamed the asteroid formerly known as 81948 (2000 OM69) to “Eno” as a tribute to musician, composer and record producer Brian Eno. Eno was described as “an experimental sculptor of sound” and has become synonymous with ambient music. The honour came just a day after Eno was presented with the Stephen Hawking Medal at Starmus 2019 for the reissue of his 1983 album, “Apollo: Atmospheres and Soundtracks”.

Asteroids can have a Moon

About 15% of asteroids are in binary systems, and the smaller of these pairs is referred to as a moon. The Asteroid Impact and Deflection Assessment (AIDA) mission proposes to send a pair of space probes to study and demonstrate the effects of crashing a spacecraft into an asteroid. NASA’s Dart spacecraft will impact the moonlet, “Didymoon”, that orbits the larger asteroid Didymos. The European Space Agency’s Hera spacecraft will follow-up with a detail survey of the results of the impact. The mission will help explore the possibility of deflecting this type of asteroid and formulate ways to protect Earth from harmful space rocks.

Astrophysicist and Musician, Brian May, describes ESA’s Hera Mission

Asteroid with Enough Metal to Make Everyone Rich

It’s estimated that asteroid Psyche 16 contains various metals worth $10,000 quadrillion Mining all its metal could make everyone on Earth a billionaire, or could destroy commodity prices and cause the world’s economy to collapse. Pysche 16 is one of the ten most massive asteroids in he asteroid belt. It was discovered by the Italian astronomer Annibale de Gasparis in 1852

Artist’s conception of the asteroid 16 Psyche. Image credit: Maxar/ASU/P. Rubin/NASA/JPL-Caltech

Scientists classify Psyche 16 as a M-type (metallic) asteroid that is comprised mostly of metallic iron and nickel similar to Earth’s core. Psyche 16 could be an exposed core of an early planet, maybe as large as Mars. NASA is launching a mission to probe the asteroid in the summer of 2022. The “Discovery Mission” should arrive at Psyche 16 in 2026. This will be the first mission to explore a world of metal rather than one of rock and ice.

Black Holes Undressed

Black holes, event horizons, and singularities are weird concepts that just seem to go together. A black hole is a region of such strong gravitational pull that nothing can escape not even light. An event horizon is the boundary of black hole – anything within the event horizon can never escape while light originating right at the event horizon could escape. A singularity is a location within a black hole where the density and gravitational force becomes infinite.

Artist’s Conception of a Black Hole. Image credit: XMM-Newton, ESA, NASA

In the case of a black hole, the singularity is hidden from view by its event horizon. So Black holes are singularities that are “dressed in black” by their event horizon and undressing a Black Hole would reveal a “Naked Singularity” – if such objects actually exist.

All black holes have an event horizon whose size or radius is proportional to the the mass the black hole according an equation derived by the German astrophysicist Karl Schwarzschild:

Rg = 2GM/c2.

where M is the mass, G is the universal gravitational constant and c is speed of light. The following table shows the radius the event horizon based on the masses of a few well-know objects.

ObjectRadius (m)
The Recently imaged black hole in the Messier 87 galaxy2×1013 
Sagittarius A* – the black hole at the center of our galaxy1×1010
The Sun
3×103
(3 km)
The Earth
9×10−3
(9 mm) 
A 70 kg Human
1×10−25 

In other words, you could create a small black hole by compressing the Earth down to a less than than the size of a Canadian dime.

The physicist, Roger Penrose, showed that every black hole contains a singularity but he could not prove that every singularity also had an event horizon. The potential existence of these naked singularities is a challenge to theoretical physics – a model of singularities would require dealing with infinities and the unification of warped space-time from general relatively with the weird behaviour of very small objects from quantum theory. If naked singularities physically exist then they could be potentially be observed because they are not hidden by an event horizon. A 2017 paper in Physical Review suggests a way that naked singularities could be detected and distinguished from black holes.

Penrose proposed that some physical principle, not yet understood, excluded the existence of naked singularities (except for Big Bang singularity). This is known as the “cosmic censorship conjecture“.

Stephen Hawking found the idea of naked singularities to be obscene and felt that singularities should be “decently hidden” in places where they cannot be seen. He bet Dr. Kip Thorne and another physicist, John Preskill that these abominations cannot possibly occur. The loser agreed “to reward the winner with clothing to cover the winner’s nakedness.” The clothing was to be embroidered with “a suitable concessionary message.”

Hawking conceded the bet after a computer simulation by Matthew Choptuik of the University of Texas in Austin showed that under very rare and contrived circumstances a black hole might collapse in such a way that its singularity would be exposed, stripped for all to see. Having lost the bet on a technicality, Dr. Hawking provided Preskill with an embarrassing t-shirt while giving a talk to 1,000 people at Caltech. The t-shirt featured a nearly-naked lady and the slogan “Nature Abhors a Naked Singularity”. Hawking also placed another bet:

Whereas Stephen W. Hawking (having lost a previous bet on this subject by not demanding genericity) still firmly believes that naked singularities are an anathema and should be prohibited by the laws of classical physics,

And whereas John Preskill and Kip Thorne (having won the previous bet) still regard naked singularities as quantum gravitational objects that might exist, unclothed by horizons, for all the Universe to see,

Therefore Hawking offers, and Preskill/Thorne accept, a wager that

When any form of classical matter or field that is incapable of becoming singular in flat spacetime is coupled to general relativity via the classical Einstein equations, then

A dynamical evolution from generic initial conditions (i.e., from an open 
set of initial data) can never produce a naked singularity 
(a past-incomplete null geodesic from scri-plus).

The loser will reward the winner with clothing to cover the winner’s nakedness. The clothing is to be embroidered with a suitable, truly concessionary message.

Stephen W. Hawking, John P. Preskill, Kip S. Thorne 
Pasadena, California, 5 February 1997

The new bet is still standing!