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Star Gazer
News
Astronomy News for Bluewater Stargazers
Vol 12 No.8 August 2018
August 2018 SGN Contents BPNP Dark Sky Weekend July 13-15
The image above by Lorraine R. captures the thin crescent Moon in
p 1: BPNP Dark Sky Weekend was Great! twilight glow just before the start of public viewing at the Bruce
p 2: Meteorites found from recent asteroid breakup Peninsula National Park on July 14, 2018. The previous night
featured cloud and rain but Saturday night was one of the best of
p 3: Martian dust storm update and BPNP Mars image the year for astronomical viewing. After a laser show by yours truly,
p 4: Newly-born planet spotted and another destroyed campers were treated to views through a variety of telescopes
ranging from a 4-inch Televue refractor to our 28-inch Webster.
p 5: Twelve new moons for Jupiter Featured planets were Jupiter with the great Red Spot easily
p 6:Double shadow transits and R Coronae Borealis (var) visible, as well as Saturn with Cassini division, a faint band across
its equator and several moons. Mars, once it cleared the trees later
p 7: Quetican FoV: Zombie Star in the evening was disappointing due to the planet-wide dust storm.
p 8: Quetican FoV: (cont’d) See page 3 for more on that.
p 9: Quetican FoV: (conclusion) BAS was well represented by Lorraine R., Zoe K., Eric I., Frank P.,
p 10: Constellation page: Hercules and Corona Borealis and Cheryl D. Brett T. did yeoman duty by arranging to transport the
Webster trailer to and from the park and setting it up on Saturday
p 11: Sky Calendar: Perseid Meteors in August night. The club appreciates the efforts of these and all its volunteers
p 12: Miscellaneous page; Classified Ads in helping bring “Astronomy to the People.” Thanks guys!
p 13: Image of the Month: Moon and Venus
BAS & Astronomy Events August 2018
Times in 24 hr format unless indicated otherwise
01 Wed 19:00 BAS meeting at ES Fox Observatory: Frank
Williams on Planetary Image processing (Jupiter)
04 Sat 13:18 LQ rises locally at 12:18 am EDT
06 Mon 13:35 Aldebaran 1.1°S of Moon
08 Wed 21:00 Mercury at Inferior Conjunction (not visible)
09 to 12 STARFEST (Register at www.nyaa.ca)
10 Fri 13:05 Moon at Perigee: 358 083 km
11 Sat 04:46 Partial Solar Eclipse; 40% In Greenland, N. Europe,
and Asia. Max eclipse = 80%. Not visible locally.
11 Sat 04:58 NM rises locally at 6:26 pm EDT (not visible)
11 Sat 20:00 Dark of Moon@Fox viewing is available to BAS
members/guests; contact exec member for access.
12 Sun 20:00 Perseid Meteors (90/h, Moon 4% -best of year!
Impromptu viewing at Fox, weather dependant
14 Tue 08:35 Venus 6.3°S of Moon
16 Thu 20:00 Kincardine Star gazing, public viewing at Soccer
Fields. Sponsor: NPX Innovations (see pg 12)
Viewing at BPNP occurred at the Head of Trails parking lot which was 17 Fri 05:38 Jupiter 4.5°S of Moon
cordoned off to only pedestrians for the occasion. The scene above 17 Fri 11:00 Venus at Greatest Elongation 45.9°E
shows the expanse of dark sky with Milky Way in centre, Mars rising at
left and Jupiter at right. Saturn is in the MW glow above the Sagittarius 18 Sat 02:49 FQ rises locally at 2:40 pm EDT
Teapot. The 2.2 day-old crescent was below the horizon when this image 20 Mon 21:09 Mercury 4.8°S of Beehive
was taken at 11:07 pm. Check Lorraine’s image (upper right), the thin 21 Tue 04:55 Saturn 2.1°S of Moon
crescent is visible in that image. We were looking west over Cyprus Lake 21 Tue 19:00 Rod Smith OS Cubs Group @Fox (private tour)
trying to spot Mercury about a degree below the Moon. It was indeed 23 Thu 06:23 Moon at Apogee: 405 744 km
seen in binoculars and then naked eye just below the Moon once it got
26 Sun 06:56 FM rises locally at 8:35 pm EDT
dark enough to pick out its 0.7 magnitude glow. The main viewing party
broke up after midnight but after returning to the campsite, we were still 26 Sun 15:00 Mercury at Greatest Elongation 18.3°W
wound up and spent some time watching meteors over Cyprus Lake. All 31 Fri 23:45 Venus 1.0°S of Spica
agreed it was one of the best observing nights of the year.
SGN Astronomy News August 2018 pg 2
Disclaimer: S G N reports on the activities of the Bluewater BAS Executive 2017-2019
Astronomical Society (formerly Bruce County Astronomical President: John Hlynialuk stargazerjohn@rogers.com
Society) but any opinions presented herein are not necessarily V-President: temp. vacant
endorsed by BAS. For up-to-date details see the BAS website Secretary: Lorraine Rodgers lorrainerodgers64@gmail.com
at www.bluewaterastronomy.com relating to BAS events. SGN Treasurer: Cheryl Dawson cheryl.dawson@bell.net
is produced and edited by John Hlynialuk and I am solely Memb-at-Lrg: Brett Tatton bretttatton@gmail.com
responsible for its content. Your original articles, images, opinions, Membership: David Skelton dskel@golden.net
comments, observing reports, etc., are welcome. I reserve the right to edit for Social Media: Zoë Kessler kudra44@gmail.com
brevity or clarity. Errors or omissions are entirely mine. I will not publish your
emails or other materials without your specific permission. No part of this
publication shall be reproduced in any form whatsoever without the editor’s
consent. However, the Sky Calendar and SGN Constellation pages are free to
copy for non-commercial use. Feel free to forward this issue in its entirety to
friends. Email comments and/or submissions to stargazerjohn@rogers.com
Meteorites recovered from
June 2 Asteroid Burnup
On Saturday, 23 June, a fresh meteorite was recovered in
Botswana’s Central Kalahari Game Reserve (CKGR).
The meteorite is one of the fragments of asteroid 2018 LA
which collided with Earth on June 2, 2018 and turned into
a meteor fireball that detonated over Botswana a few
seconds after entering the atmosphere. The incident was
witnessed by a number of spectators in Botswana and
neighbouring countries and was captured on numerous
security cameras.
Asteroid 2018 LA was detected in space eight hours
before hitting Earth by the Catalina Sky Survey, operated
by the University of Arizona and sponsored by NASA as
part of its Planetary Defence mission. This is the third
time in history that an asteroid inbound to hit Earth was
detected early and only the second time that fragments
were recovered. After disruption, the asteroid fragments
were blown by the wind while falling down, scattering over
a wide area. Calculations of the landing area were done
independently by a US-based group headed by Peter
Jenniskens, of the NASA-sponsored SETI Institute in California, as
well as Esko Lyytinen and Jarmo Moilanen of the Finnish Fireball Meteorites are protected under Botswana law and samples will be
Network (FFN). curated by the Botswana National Museum and investigated
further by a research consortium of scientists coordinated by
The first meteorite was found after five days of searching by a Botswana Geoscience Institute (BGI).
team of geoscientists from Botswana International University of
Science and Technology (BUIST), Botswana Geoscience Institute For more information and/or media interviews contact:
(BGI) and University of Botswana’s Okavango Research Institute Finnish Fireball Network and University of Helsinki
(ORI). The Department of Wildlife and National Parks granted Tomas Kohout tomas.kohout@helsinki.fi
access and deployed park rangers for protection and participation
in the search. The importance of the find is two-fold:
It has enormous scientific value and it allows to
better calibrate the so-called “Earth Defense”
against impacting asteroids.
Jenniskens, who traveled to Botswana to assist in
the search, teamed up with Oliver Moses (from
ORI), to gather security surveillance videos in
Rakops and Maun, to get better constraints on the
position and altitude of the fireball’s explosion.
Professor Alexander Proyer, from BIUST, led the
joint expedition while Mohutsiwa Gabadirwe, BGI
senior curator, coordinated access to the protected
fall area in the game reserve. Professor Roger
Gibson, Head of School at the School of
Geosciences at the University of the Witwatersrand
in Johannesburg, South Africa, also assisted in
locating the fall area. The meteorite was eventually
spotted by BIUST geologist Lesedi Seitshiro. The
search for more fragments of the meteorite
continues. Dr Fulvio Franchi of BIUST, is leading
the follow-up search team joined by Tomas Kohout
of the FFN and the University of Helsinki.
SGN Martian Dust Storm Update August 2018 pg 3
Martian Dust Storm
Continues
Roger Venable, coordinator of the
Association of Lunar and Planetary
Observers (ALPO) Mars Section,
describes the current storm as "unique
in the history of observed Martian dust
storms. All of the historical dust storms
of this size began in the southern
hemisphere, in the areas of Hellas,
Noachis, or Argyre," said Venable in an
e-mail. "The present global dust storm
began in Mare Acidalium [in northern
hemisphere]. There has been
considerable dust activity in Mare
Acidalium in the last several
apparitions, but nothing on this scale
was expected.”
The storm then expanded into southern
regions and kept going until by June 19,
the entire planet was shrouded. NASA’s
Rover Opportunity which went into a
hunkered-down mode has not been heard from since
June 10. Roger Venable says: ”Generally, once the dense dust ABOVE: Early- and mid-
cores cease to occur, a relatively uniform haze of dust storm photos of the same
Amateur observers have been chewing their nails continues over the entire planet for a couple of hemisphere of Mars. In
waiting for a break in the storm but the only things months, gradually settling [editor’s emphasis]. The the left image by Damian
noticeable are an overall fifth of a magnitude increase normal albedo features of the planet gradually Peach, the large, India-
in brightness and a subtle change in the colour of the reappear, regaining their normal contrast.” shaped albedo feature is
planet from its usual reddish-orange (or pink) to a Syrtis Major, site of an
pumpkin orange hue. Few telescopic observers have Both the dust storms and the low altitude of Mars in ancient shield volcano. In
noticed even a polar cap glowing feebly through the our sky are making this a challenging year for Mars- right image by Christophe
haze. watching, but observers remain hopeful. Be sure to Pellier, notice how much
use Sky & Telescope's Mars Profiler to find out which dust covers Syrtis Major
Scott Guzewich, atmospheric scientist at NASA’s hemisphere of the planet faces your location at the and the south polar
Goddard Space Flight Center, struck a note of time of observing. If the seeing's decent, up the region. South is up in both
optimism, writing in a July 5th blog that "the amount magnification to 200x or higher and try to make out images. Sky&Telescope
of dust over Gale Crater has been slowly declining the most prominent dark markings or the polar cap.
over the last two weeks, and it’s possible the dust You can also try a red filter to improve surface feature
storm has reached its ‘peak”’. contrast; a Wratten 25 or 29 (for bigger scopes) works
well. For vapour clouds, use a Wratten 80A or 82A.
OK, Mars is BRIGHT, but not THAT
bright! Around midnight July 14 at the
Bruce Peninsula National Park, the lens
fogged up for the last dozen or so images.
This one was made at 12:26 am July 15
and shows the “red light gang” putting the
Webster back into the trailer. None of us
used white light, so the view is somewhat
over-illuminated in red light.
In the background, the Milky Way rides
high and Saturn is still visible just above
the Teapot in the centre of the image.
Mars by that time had cleared the trees to
the east and was high enough that many
saw it in scopes before the night ended.
Here the haze on the lens makes it stand
out like the proverbial sore thumb. Even
without the hazy enhancement, Mars was
bright, shining at around magnitude
negative 2.5 or so. Estimates indicate that
the dust storm currently hiding surface
features has brightened Mars by about 0.2
magnitude. Personally, I would be happy
without the enhancement. Canon 6D
image, Samyang 12 mm lens, f/2.8, ISO
6400, 20 s. exp.
SGN Exoplanet Birth and Death August 2018 pg 4
Newborn Planet Spotted by
SPHERE
A newborn planet orbiting a star just 370 light-
years from Earth has been spotted by
astronomers using the European Southern
Observatory’s Very Large Telescope (VLT) in
Chile. Dubbed PDS 70b, the huge planet is the
first-ever to be seen orbiting within a disc of
planet-forming material. Its discovery could
provide important clues as to how systems of
planets form around stars.
PDS 70b is a gas giant with a mass that is
believed to be several times that of Jupiter. It
orbits a very young star called PDS 70, which is
about 10 million years old and is surrounded by
a dense protoplanetary disc of dust and gas. The
disk appears to have a void near its centre,
which has probably been cleared by the young
planet. Astronomers have known about such
voids for decades and have long speculated that PDS 70b (bright spot to the right of the black disc) has cleared some of the protoplanetary
they are associated with young planets. disc surrounding PDS 70 (obscured by the black disc). Courtesy: ESO/A. Müller et al
Birthplaces of planets
“These discs around young stars are the birthplaces of planets, but Müller and colleagues, the upper limit is somewhat greater than
so far only a handful of observations have detected hints of baby expected for the age of the planet – which they estimate to be
planets in them,” explains Miriam Keppler of Germany’s Max Planck 5.4 million years. Spectroscopic studies of light from the planet
Institute of Astronomy in Heidelberg, who led the team that suggest that it has a cloudy atmosphere.
discovered PDS 70b. She adds, “The problem is that until now, most
of these planet candidates could just have been features in the disc”. SPHERE (Spectro-Polarimetric High-contrast Exoplanet REsearch
instrument) detects the faint light from planets by blocking the
The discovery inspired a follow-up study that was led by Keppler’s brighter light from the parent star using a coronagraph. Then a series
Heidelberg-based colleague André Müller and looked more closely at of images is taken of the system over time. The position of the planet
PDS 70b and how it interacts with the planetary disc. This revealed will change slightly, while the star will appear stationary. By looking at
that the planet is orbiting in the middle of the void at a distance of how the image changes with time, astronomers can extract the light
about 22 au from the star – which in the solar system would put it from the planet and reject light from the star.
just beyond Uranus.
The studies will be described in two papers to be published in
The surface temperature of PDS 70b is about 1000 °C and the Astronomy & Astrophysics and preprints are now available: Miriam
radius of the planet is 1.4-3.7 times that of Jupiter. According to Keppler et al; and André Müller et al.
Chandra May Have First Evidence of a now in the process of devouring the planetary debris. This discovery
gives insight into the processes affecting the survival of infant planets.
Young Star Devouring a Planet
Press Release Chandra July 16, 2018 Since 1937, astronomers have puzzled over the curious variability of a
Scientists may have observed, for the first time, the destruction of a young star named RW Aur A, about 450 light years distant whose
young planet or planets around a nearby star. Observations from optical light, every few decades, has faded briefly before brightening
NASA’s Chandra X-ray Observatory indicate that the parent star is again. In recent years, astronomers have observed the star dimming
more frequently, and for longer periods.
Using Chandra, a team of scientists may have uncovered what
caused the star's most recent dimming event: a collision of two infant
planetary bodies, including at least one object large enough to be a
planet. As the resulting planetary debris fell into the star, it would
generate a thick veil of dust and gas, temporarily obscuring the star's
light. "Computer simulations have long predicted that planets can fall
into a young star, but we have never before observed that," says Hans
Moritz Guenther, a research scientist in MIT's Kavli Institute for
Astrophysics and Space Research who led the study just published in
the Astronomical Journal. "If our interpretation of the data is correct,
this would be the first time that we directly observe a young star
devouring a planet or planets.” The observation in 2017 showed
strong emission from iron atoms, indicating that the disk contained at
least 10 times more iron than in the 2013 observation during a bright
period.
Guenther and colleagues suggest the excess iron was created when
two planetesimals, or infant planetary bodies, collided. The full release
is here: http://chandra.si.edu/press/18_releases/press_071818.html
llustration: NASA/CXC/M.Weiss; X-ray spectrum: NASA/CXC/MIT/
H.M.Günther
SGN Jupiter: Still King of Moons August 2018 pg 5
than the prograde group of moons and takes about one and a half
A Dozen New Moons Of Jupiter years to orbit Jupiter. So, unlike the closer-in prograde group of
moons, this new oddball prograde moon has an orbit that crosses the
Discovered, Including One outer retrograde moons. As a result, head-on collisions are much
more likely to occur between the “oddball” prograde and the
“Oddball” retrograde moons, which are moving in opposite directions.
Carnegie Institute For Science Press Release July 16, 2018
“This is an unstable situation,” said Sheppard. “Head-on collisions
would quickly break apart and grind the objects down to dust.” It’s
Washington, Dc—Twelve new moons orbiting Jupiter have been possible the various orbital moon groupings we see today were
found—11 “normal” outer moons, and one that they’re calling an formed in the distant past through this exact mechanism. The team
“oddball.” This brings Jupiter’s total number of known moons to a think this small “oddball” prograde moon could be the last-remaining
whopping 79—the most of any planet in our Solar System. remnant of a once-larger prograde-orbiting moon that formed some of
the retrograde moon groupings during past head-on collisions. The
A team led by Carnegie’s Scott S. Sheppard first spotted the moons in name Valetudo has been proposed for it, after the Roman god
the spring of 2017 while they were looking for very distant solar Jupiter’s great-granddaughter, the goddess of health and hygiene.
system objects as part of the hunt for a possible massive planet far
beyond Pluto. In 2014, this same team found the object with the most- Elucidating the complex influences that shaped a moon’s orbital
distant known orbit in our solar system and was the first to realize that history can teach scientists about our solar system’s early years. For
an unknown massive planet at the fringes of our Solar System, far example, the discovery that the smallest moons in Jupiter’s various
beyond Pluto, could explain the similarity of the orbits of several small orbital groups are still abundant suggests the collisions that created
extremely distant objects. This putative planet is now sometimes them occurred after the era of planet formation, when the Sun was
popularly called Planet X or Planet Nine. University of Hawaii’s Dave still surrounded by a rotating disk of gas and dust from which the
Tholen and Northern Arizona University’s Chad Trujillo are also part of planets were born. Because of their sizes—one to three kilometres—
the planet search team. these moons are more influenced by surrounding gas and dust. If
“Jupiter just happened to be in
the sky near the search fields
where we were looking for
extremely distant solar system
objects, so we were
serendipitously able to look for
new moons around Jupiter
while at the same time looking
for planets at the fringes of our
solar system,” said Sheppard.
Gareth Williams at the
International Astronomical
Union’s Minor Planet Center
used the team’s observations
to calculate orbits for the newly
found moons. “It takes several
observations to confirm an
object actually orbits around
Jupiter,” Williams said. “So, the
whole process took a year.”
Nine of the new moons are
part of a distant outer swarm of
moons that orbit it in the
retrograde, or opposite
direction of Jupiter’s spin
rotation. [Red orbits diagram
right] These distant retrograde
moons are grouped into at
least three distinct orbital groupings and are thought to be the these raw materials had still been present when Jupiter’s first
remnants of three once-larger parent bodies that broke apart during generation of moons collided to form its current clustered groupings of
collisions with asteroids, comets, or other moons. The newly moons, the drag exerted by any remaining gas and dust on the
discovered retrograde moons take about two years to orbit Jupiter. smaller moons would have been sufficient to cause them to spiral
inwards toward Jupiter. Their existence shows that they were likely
Two of the new discoveries are part of a closer, inner group of moons formed after this gas and dust dissipated.
that orbit in the prograde, or same direction as the planet’s rotation.
[blue orbits] These inner prograde moons all have similar orbital The initial discovery of most of the new moons were made on the
distances and angles of inclinations around Jupiter and so are Blanco 4-meter telescope at Cerro Tololo Inter-American in Chile and
thought to also be fragments of a larger moon that was broken apart. operated by the U.S. National Optical Astronomical Observatory.
These two newly discovered moons take a little less than a year to Several telescopes were used to confirm the finds, including the 6.5-
travel around Jupiter. meter Magellan telescope at Carnegie’s Las Campanas Observatory
in Chile; the 4-meter Discovery Channel Telescope at Lowell
“Our other discovery [green orbit] is a real oddball and has an orbit Observatory Arizona, the 8-meter Subaru Telescope and the
like no other known Jovian moon,” Sheppard explained. “It’s also University of Hawaii 2.2 meter telescope and the 8-meter Gemini
likely Jupiter’s smallest known moon, being less than one kilometre in Telescope in Hawaii.
diameter”. This new “oddball” moon is more distant and more inclined
SGN Jovian Double Moon Shadow Transits August 2018 pg 6
Double Shadow Transits on Jupiter Timetable:
The planet Jupiter undergoes almost a dozen double moon shadow Date Time (UT) Jupiter altitude Visibility from area
transits this month according to the RASC Observer’s Handbook. It is Aug 2 20:18 16° in daylight
remarkable however, how many of those transits will not be visible Aug 6 9:16 -51° below horizon
from our area! A total of 7 occur when Jupiter is below our horizon. An Aug 9 22:13 29° in daylight
additional 3 occur in daytime. Only one occurs in darkness with Aug 13 11:10 -60° below horizon
Jupiter in our sky, the Aug 24 (2:35 UT) event i.e., Aug 23 at 10:35 pm Aug 15 5:39 -42° below horizon
EDT and even then Jupiter is only 4° above the western horizon at the Aug 17 0:08 27° Aug 16 (8:08 pm EDT) in daylight
start. You can try for the events in daylight Aug 2, 9 and 17, but a Aug 20 13:16 -42° below horizon
GOTO scope is required that is accurately aligned. Aug 22 8:50 -46° below horizon
Aug 24 2:35 4° Jupiter setting late Aug 23
Aug 27 15:54 -12° below horizon
Aug 31 5:12 -60° below horizon
Aug 23 Double Shadow Transit
The appearance of Jupiter part way through the transits
on Aug 24 (late Aug 23) is shown in this view from Starry
Night. Io and Europa are the moons involved and while
the event stats at 10:35 pm when Europa’s shadow
appears, there are two shadows on the planet until just
after midnight, when Io’s shadow leaves the disk. The
image left shows the shadows and the Great Red Spot at
about 11:08 pm Aug 23 just a minute before Jupiter sets
below the western horizon. Note the Red Spot rising. This
double transit will be a challenge to observe because
Jupiter is only 4° high (and dropping) at the start of the
event. The Aug 1 BAS meeting wth Frank W. will provide
some practical advice on how to image Jupiter.
Incidentally, all four Galilean Moons will be on the same
side of Jupiter Aug 23. Good luck with your observations.
R Coronae Borealis is due for a Fall Below: R Coronae Borealis indicated by arrows, is barely
visible in this image taken July 25, 2018. Comparison star
Coronae Borealis (R CrB) is an irregular variable star that recently magnitudes (Starry Night Pro 6) indicate R CrB seems to be
became even more irregular. The light curve below shows that the star close to magnitude 8.1, 2 magnitudes below its “normal”
stays around magnitude 6, almost visible to the naked eye, for months, maximum. It should be visible in binoculars. Blue background
then drops to magnitude 14 or 15, literally disappearing from most colour in the image is due to sunlight reflected from the gibbous
amateur telescopes. Then it returns to 6th magnitude and starts another Moon brightening the sky to the east of Corona Borealis. The
cycle. An unprecedented drop however occurred in mid-2010 when brightest star in Corona Borealis is 2.2 magnitude Gemma,
RCrB faded almost 10 magnitudes to 15! Then rather than returning to which is the brightest star near the lower centre of this image.
normality quickly, it lingered below magnitude 10 for years and only
came back to 7th at the start of 2018. It has stayed above magnitude 8 The image by John H. was taken with a Canon 6D using a
for over a year and is due for another fade out in the near future 24-105 mm lens at 105 mm, f/4.0, ISO 4000, exp. = 2 s.
(maybe). In any case, do keep an eye out for it and report any absence
in its charted location.
4
6
8
Magnitude
10
12
14
03-21 1990 01-23 1997 11-28 2003 10-02 2010 07-27 2017
Quetican Field of View by Doug Cunningham August 2018 pg 7
The Zombie Star– SN PTF14hls
or: Everything you need to know
about supernovae
“The night sky does not come with fruits and flowers…
but with stars and stardust, mystery, and nirvana.”
John Burroughs 1837 -1921
American Conservationist and Naturalist
Talk about mystery and nirvana! The science of astronomy is continuously
discovering new phenomena that push the boundaries of our knowledge and
imaginations. It becomes especially interesting when “new stars” suddenly
appear, either as novae, or supernovae. As a former member of AAVSO
(American Association of Variable Star Observers) I really like that.
Imagine Danish astronomer Tycho Brahe’s surprise and stunning amazement
when, on November 11th, 1572, while returning home after dinner, he looked
up and observed a new star, shining as bright as Venus, in the constellation of
Cassiopeia. This couldn’t be happening because according to the ancient
teachings of Aristotle, the “eighth sphere of the fixed stars” was immutable.
So much for Aristotle. Listen to Tycho’s description:
“When I had satisfied myself that no star of that kind had ever
shone forth before, I was led into such perplexity by the
unbelievability of the thing, that I began to doubt the faith of
my own eyes. I enquired of my servants, who were
accompanying me, whether they too could see a certain bright
star directly overhead. They immediately replied with one voice
that they saw it completely and that it was extremely bright.”
Right: Star map of
Cassiopeia showing the
position (labelled with the
Tycho’s
letter I) of the supernova
Supernova
of 1572; from Tycho
SN 1572
Brahe's De nova stella.
Below: Tycho Brahe
Remnant of Tycho’s Star SN 1572 imaged in X-Rays
from the Chandra X-Ray Observatory
It is now accepted that Tycho’s star was a Type 1a
Supernova, located within the boundaries of Cassiopeia.
It reached a visual magnitude of -4, and was located
between 8,000 ly and 9800 ly distant (well within the
confines of our Milky Way). It produced a supernova
remnant which has been imaged with the Chandra X-
Ray Observatory (among other instruments). Readers
are probably aware that a Type 1a supernova occurs
within a binary star system in which one member, a
white dwarf star, accretes matter from a companion star
From the Editor: until it exceeds a mass of 1.4 solar masses, at which
Tycho Brahe -Winner of Darwin Award 1999 time the white dwarf detonates in a brilliant Type 1a
Totally by coincidence, I was re-reading a copy of the Darwin Awards -2000 edition and SN explosion. [See the sidebar on next page for more
Tycho Brahe’s name came up as a winner. Darwin Awards are presented to a person about supernovae types.-ed] In October, 2004, Nature
who removes his (defective) genes from the human gene pool in an “extra-ordinarily
Magazine reported that astronomers had found the
idiotic manner”. I sincerely question the selection of Tycho, who in my opinion was just a
victim of protocol or at worst, bad judgement. The story goes as follows: Tycho was companion star that contributed the mass to the white
present at a state dinner and protocol says one does not leave the table before the host dwarf, causing it to become SN 1572. This companion
rises. Tycho held his bladder as best he could but it burst and he died 11 days later as a star is a G2 star similar to our Sun.
result of infection. It would have been an excruciatingly painful demise and that alone in
my book absolves him from being “honoured” this way. Besides, Tycho was a meticulous
observer and builder of many remarkable astronomical devices, including an incredible
observatory called Uraniborg. in my book, the guy deserves respect not ridicule.
Quetican Field of View Zombie Star -cont’d August 2018 pg 8
There are 5 main classes of A selection of supernovae
supernovae [plus several subclasses,
see Wikipedia chart at right -ed] but and supernova remnants
for simplicity, the majority of
supernovae fall into either a Type 1, or
a Type 2 category. Astronomers can
distinguish among the various types
of supernovae by analyzing their light
spectra.
For example, Type 1 supernovae do
not display hydrogen lines in their
spectra, while Type 2 supernovae
show hydrogen lines. SN 1994D (bright spot lower Multiwavelength X-ray, infrared, The Crab Nebula is a pulsar
left), a Type Ia supernova and optical compilation image wind nebula associated with
Type 2 supernovae are fascinating outshining its home galaxy, of Kepler's supernova remnant, the 1054 supernova.
beasts, and they usually occur when NGC 4526. (NASA/ESA) SN 1604. (NASA/ESA/JHU/ (NASA/ESA)
the cores of massive stars, usually red R.Sankrit&W.Blair
supergiants at the end of their life
cycles, are unable to generate the
internal pressures to support their
outer layers. Core collapse occurs so
quickly that in-falling layers slam into
each other. This generates a reverse
shock wave that blasts much of the
star out into space, creating a
supernova remnant, (SNR) and
leaving behind either a neutron star (a
pulsar), or a black hole. The light
from the hot ejected debris rises to a
maximum brightness and the
supernova continues to shine for
about 100 days before fading away.
Telescopes on Earth regularly survey
the night skies searching for transient
luminosity events, hoping to catch a
distant supernova in the early stages
of its outburst. Both amateur and
professional astronomers are active in
this pursuit. On Mount Palomar, near
San Diego, California, there is a Material above from Wikipedia. See this link for original:
special purpose, wide-field Schmidt https://en.wikipedia.org/wiki/Supernova
telescope designed specifically for
this hunt. The search is called the
Intermediate Palomar Transient
Factory Survey and uses the Samuel
Orschin 48 inch Schmidt telescope. This telescope in 2014 was the times longer than a typical Type 2 supernova. Note that the light
prime workhorse for Iair Arcavi. In September, 2014, the telescope, curve was interrupted when the Sun came between SN IPTF14hls
recorded a supernova in a 17.7 magnitude, dwarf galaxy, located just and the Earth. [text continues at bottom of next page]
below the Big Dipper, at over 500 million ly distance. This is a huge
distance! Consider that the Andromeda Galaxy (M31), our closest
large galaxy, is only 2.5 million ly away. At the time of its discovery,
this supernova, although brighter than a typical Type 2 SN, displayed
hydrogen lines and didn’t seem to warrant special attention.
Astronomers, like Iair Arcavi, initially thought it was a normal, core
collapse Type 2 supernova.
Then, things got very strange. Three months later, this supernova,
rather than becoming dimmer, remained bright, and then, over the
next months, became even brighter. It almost seemed like multiple
explosions were occurring. Look at the light curve below provided
by Las Cumbres Observatory. The data show that SN IPTF14hls,
about 230 days since its discovery, was shining with a luminosity of
close to 3.5 billion Suns. As well, this Type 2 supernova lasted 4 Discovery image of SN IPTF14hls (Sep 2014)
Las Cumbres Observatory
SGN Zombie Star -cont’d August 2018 pg 9
Left: Light curve SN IPTF14hl
This light curve uses the vertical axis to display
the brightness of the star in multiples of the
brightness of the Sun (note the billions!) versus
the duration in days horizontally. Other such
graphs provide brightness in magnitudes or use
luminosity with the Sun set to 1.0. This graph
does not provide an actual visual magnitude since
the star at maximum was barely brighter than the
17.7 magnitude dwarf galaxy where it was
located. The actual brightness (absolute
magnitude or luminosity) is a calculated value
based on apparent brightness and distance. The
dwarf galaxy was found to be 500 million ly
away, about 40 times the distance to the
Andromeda Galaxy, so even at 17th magnitude, it
was billions of times brighter than the Sun.
Besides its high brightness (compare a normal
supernova shown in blue), this supernova is
remarkable for its duration, staying bright for 3 to
4 times longer than normal supernovae. Also
remarkable is the fact that it appears to have had
at least 3 additional “explosions” along with the
Light curve for SN IPTF14hl courtesy original outburst.
of Las Cumbres Observatory Diagram courtesy of Las Cumbres Observatory
Right: Images of SN IPTF14hl
area in 1954 and 1993:
Two archival images taken of the
dwarf galaxy in Ursa Major
show a previous eruption of the
“Zombie Star” in 1954. The
1993 image shows no activity.
The 2014 image on page 8,
indicates a second eruption and
so the object may be a recurring
supernova like a few others that
have been recorded in the past.
It’s not surprising that the strange luminosity fluctuations of SN supernova until, finally, a massive black hole forms and ends the
IPTF14hls prompted a check on past images of the dwarf galaxy repetitions.
to see if this supernova prospect had experienced a previous
outburst. Look at the comparison images between a 1954 outburst I guess that is why CNN, on November 8th, 2017, called this star
and 1993 image showing no outburst. Apparently, this supernova the “Zombie Star” meaning one that has survived multiple
candidate had a history of at least one previous outburst. Very supernova explosions and returns to partial life only to explode as a
strange, a repeating supernova? Almost like the zombie from supernova again. For me, ever since I was in Grade 7, the big
science fiction, where true death can’t bring final closure. attraction of science in general, and astronomy in particular, is that
the Universe we inhabit continually serves up wonder, mystery, and
What a mystery! Although the data is still incomplete, the evidence yes, nirvana!
seems to rule out the common Type 2 supernova models to explain
the behaviour of SN iPTF14his. After all, we have a supernova that Nirvana, a Definition:
seems to repeat. So what is left? A most unusual model called a Our columnist uses the term nirvana, several times in his story about
“pair instability supernova” (PISN) has been advanced. This theory supernovae and at first I was not sure what it meant exactly. But here are
postulates that, for supermassive stars greater than 100 solar some definitions from various sources. I think it is actually quite
masses, the cores become so hot that radiation energy is converted appropriate.
into matter and anti-matter. This results in a loss of radiation
Nirvana: origin Sanskrit, literally meaning “extinction, disappearance, to be
pressure and the core collapses in on itself, creating a massive
blown away, as when your spirit reaches the ultimate understanding and
explosion that blows off the outer layers in a supernova explosion. melding with the universe. In Hinduism and Buddhism, nirvana is “the
Because the progenitor star is so massive, it is theorized that this beatitude that transcends the cycle of reincarnation; characterized by the
process can repeat itself over decades, creating a repeatable Type 2 extinction of desire and suffering and individual consciousness” or “a state
of supreme happiness.”. Personally, I think the “blown away” part fits very
Featured Constellations: Hercules, Corona Borealis August 2018 pg 10
Hercules (Her) Corona Borealis (CBr)
α-Herculis - Ras Algethi ζ− Herculis - Ruticulus
α-Coronae Borealis -Gemma β-Coronae Borealis - Nusakan
λ−Herculis - Masym β−Herculis _ Kornephoros
κ−Herculis - Marfik ω−Herculis - Cujam Corona Borealis is a very attractive semicircular group of stars
between Hercules and Bootes, all the stars being of the 4th and 5th
The keystone-shaped figure formed by the stars π, η, ζ and ε
magnitudes with the exception of Gemma, the "Pearl of the Crown."
Herculis helps to identify this constellation; also the stars θ and
There are a relatively large number of variable stars in this
ι−Herculis. representing respectively the bent left knee and the left
constellation; two of them, both irregular variables, are especially
foot of the kneeling Hercules, appear to rest directly on the head of
interesting. R Coronae (Location 162132) remains for months and
Draco, the Dragon. It is one of the most ancient of the
sometimes years as a 6th magnitude star; then, for no apparent
constellations. The outstanding feature of Hercules is the great
reason it will decrease rapidly to the 12th or 13th magnitude.*
globular cluster M13, the finest visible in the northern latitudes. On
T Coronae is even stranger; normally a 9th magnitude star, in May
dark nights it is barely visible to the naked eye but it is easily seen
1866 it suddenly became very bright, reaching the 2nd magnitude.
in fieldglasses. A small telescope begins to reveal its beauty, while
In 1946 it suddenly brightened again to the 3rd magnitude, only to
al least a 4" telescope is necessary to resolve the stars, in a large
fade again to its original brightness. It belongs to a special group of
telescope, it is a never-to-be-forgotten sight. There are thought to
stars known as recurrent novae.
be no less than 100,000 stars in this cluster. Ras Algethi is a binary
and also an irregular variable, varying in magnitude from 3.1 to 3.9. DOUBLE STARS (CrB)
Mag. Sep (s) Location Remarks
DOUBLE STARS (Her)
ζ 5.1-6.0 6 153837 Greenish White-Green.
Mag. Sep (s) Location Remarks ε 6.0-7.0 0.8 152131
α 3.1 to 3.9-5.4 5 171314 Orange-blue, beautiful. ν 5.3-5.4 371 162034 Both Golden.
γ 3.8-9.0 41 161919 White-Lilac, σ 5.8-6.7 5 161334
δ 3.0-8.1 11 171325 Green-Pale Purple. Σ1964 7.3-7.4-8.8 15-2 153737 Triple.
ζ 2.9-5.5 1 164032 23 6.3-8.8 35 162132
κ 5.3-6.5 29 160518 Yellow -Red, Corona Borealis contains no Messier objects
μ 3.4-9.8 33 174528
ρ 4.5-5.5 4 172237 Both Pale Green, *R Coronae Borealis: R-CBr (finder chart lower left) stays at 6th
95 5.1-5.2 6 175922 Green-Red. magnitude for years and then, unpredictably, drops to 13th to 15th
100 5.9-6.0 14 180526 A striking pair. magnitude in a few weeks. Months later it is back to magnitude 6.
Σ2063 5.7-8.2 16 163146 Carbon in the atmosphere appears to be the culprit and one theory
says that carbon particles, i.e. soot, build up in the atmosphere to a
Σ2101 6.3-9.0 4 164436 point where they eventually condense and are ejected as a dust
Σ2104 6.2-8.0 6 164736 Beautiful. shell. The star returns to normal brightness and the cycle repeats.
Σ2190 6.0-9.5 10 173421 R CrB is currently at its bright phase but it could wink out anytime!
Σ2277 6.3-8.2-9.9 27-88 180249 Triple. More about R CrB and a current image is found on page 6.
MESSIER OBJECTS (Her)
Mag Location Remarks
M 13 5.7 164037 Globular Cluster. The “Hercules Cluster”.
See above.
M 92 6.2 171643 Globular Cluster. [Some say this is the 2nd
best globular in the sky.]
Other Objects of Interest in Her
NGC 6210 -Planetary Nebula Magnitude 10, Location 164324
u Herculis -Eclipsing variable, magnitude range 4.8-5.3,
period 2 days 1 hr. 12 min. Location 171533
S Herculis -Long period (307 days) variable, maximum magnitude
7.6. Location 165015.
R CRB Finder Chart (from Starry Night) See pg 6
for image showing current brightness of this star.
Chart Legend
Star Location
Double Stars
+ Nebulae
Clusters
* Variable Stars
VarSGN Sky Calendar August 2018 pg 11
August 2018 Times in 24 hr format unless indicated otherwise
01 Wed 19:00 BAS meeting at ES Fox Observatory: Frank
Planets MERCURY is near the Sun until late August
when it becomes an easy Morning Star. On Aug
26, it is farthest ahead of the morning Sun and
Williams on Planetary Image processing (Jupiter) good viewing continues into September. VENUS (-4.3) reaches its
04 Sat 13:18 LQ rises locally at 12:18 am EDT
farthest point from the Sun on Aug 17, but it is also lower in
06 Mon 13:35 Aldebaran 1.1°S of Moon declination and stays nearer to the horizon than earlier. On August
08 Wed 21:00 Mercury at Inferior Conjunction (not visible) 14, it is 6° below a 4-day old crescent Moon with Spica 13° east.
09 to 12 STARFEST (Register at www.nyaa.ca) MARS, starts to decrease in brightness fading from -2.8 to -2.1
10 Fri 13:05 Moon at Perigee: 358 083 km and disk size shrinks to 21 arc-seconds by month-end.
11 Sat 04:46 Partial Solar Eclipse; 40% In Greenland, N. Europe, JUPITER, (-1.9) is much lower in the west by sunset and by month
and Asia. Max eclipse = 80%. Not visible locally. end is setting around 10:30 pm EDT. There are almost a dozen
11 Sat 04:58 NM rises locally at 6:26 pm EDT (not visible) double shadow transits across Jupiter this month, but don’t get too
11 Sat 20:00 Dark of Moon@Fox viewing is available to BAS excited, -see pg 6. SATURN, (mag. +0.3) is fairy high at dark and
members/guests; contact exec member for access. sets by 1 am EDT at month end. Still good viewing with a maximum
12 Sun 20:00 Perseid Meteors (90/h, Moon 4% -best of year! ring tilt. URANUS, (5.8) is in Pisces while NEPTUNE, (7.9) is in
Aquarius. Both are in dark sky by midnight and rise by 10 pm near
Impromptu viewing at Fox, weather dependant
month end. Dwarf planet, Ceres (7.5) is in Leo, and by month end
14 Tue 08:35 Venus 6.3°S of Moon
is a difficult target. Asteroid, Vesta (5.3) is in Sagittarius, well
16 Thu 20:00 Kincardine Star gazing, public viewing at Soccer placed all night for viewing. You need a map to locate it among the
Fields. Sponsor: NPX Innovations (see pg 12.) MW stars. PLUTO (mag. 14) is near the “Lemon” in Sagittarius and
17 Fri 05:38 Jupiter 4.5°S of Moon can be spotted during the dark of the moon viewing nights coming
17 Fri 11:00 Venus at Greatest Elongation 45.9°E up. Updated 2018 finder charts for all the planets/asteroids above
18 Sat 02:49 FQ rises locally at 2:40 pm EDT are on the BAS website. Comet 21/P is due for September as well.
20 Mon 21:09 Mercury 4.8°S of Beehive
21 Tue 04:55 Saturn 2.1°S of Moon Below are sunrise/sunset times and Sun’s altitude for August. The
21 Tue 19:00 Rod Smith OS Cubs Group @Fox (private tour) Sun continues to lower in the sky this month providing more dark
23 Thu 06:23 Moon at Apogee: 405 744 km hours for viewing. The moon chart at bottom shows lunar phases
for August nights. Moonrise times (for Owen Sound) at FM, FQ, NM
26 Sun 06:56 FM rises locally at 8:35 pm EDT
and LQ are in the sky calendar listing at left. Times for other
26 Sun 15:00 Mercury at Greatest Elongation 18.3°W
locations can be found at sites like https://www.timeanddate.com.
31 Fri 23:45 Venus 1.0°S of Spica
Special Events Perseid Meteor Shower
Peaks during NM
60.9° elev. August 10
57.7° elev. August 20
The peak night of the Perseids should see 90 meteors/h, and we
have only a very thin Moon (4%) to contend with so this could be
the best meteor shower of the year if weather cooperates! Many 54.3° elev. August 30
BAS members will be back from Starfest by then and there will
likely be impromptu viewing at Fox but you only need a dark sky S
location with a view to the NE for meteor watching. Observe with
your friends and family, it should be a good show. Here is an 6:44 am EDT August 30 8:03 pm EDT
article about how to get the best out of meteor watching: Meteor 6:32 am EDT August 20 8:21 pm EDT
shower 2018 guide S&T and how to watch: Watching Meteors
6:20 am EDT August 10 8:36 pm EDT
E Sunrise Sunset W
Data for Owen Sound ON
44°35‘N lat 80°55’W long Data from
www.timeanddate.com
N
Moon Phase Chart for August 2018
created with QuickPhase Pro 4.2SGN The Miscellaneous Page August 2018 pg 12
BAS Member Loaner Scopes
Solar H-alpha scope now available.
Our Lunt solar scope can be borrowed by BAS members and it
SGN
is waiting at the Fox! Contact John to get your hands on it. We
now have a suitable mount for it as well. A short training Classified
session will be provided on pickup.
Ads Section
Several Dobs available.
One 12-inch dobsonian loaner telescope is available for free
loan to members. Smaller 8-inchers are also available. Contact (Also on BAS website)
John H. or Brett T. for availability. Scopes come in and out so
keep checking with John or Brett if you are interested in a
loaner.
Kincardine Star Party Aug 16
NPX Innovation
www.npxinnovation.ca and
BAS will hold a star night on
Aug 16 at 9 pm at the
Kincardine Soccer Fields.
BAS members: if you can
help out with a telescope
contact John H. at the usual
email.
The night starts off with
planet viewing and includes 4
planets (plus Ceres, a dwarf
planet), Venus, Jupiter, Saturn
and Mars. The night features
a 6-day-old Moon so it is not FOR SALE: 12.5 inch f/6 Dobsonian
a dark-sky night, but the main Homebuilt by experienced telescope maker in
constellations should be 1980. See Sep 2014 SGN pg 9 for build details.
visible and a laser pointer Truss tube design with full thickness Coulter
show will be provided once it mirror -one of their best, recently re-aluminized.
is dark. Here’s hoping that Focuser and secondary mirror/spider is a Novak
the dust storm on Mars has unit. Alt-azimuth mount (3/4-inch ply) is a nice
cleared enough to see some wood grain finish with coating of Varathane. This
polar caps at least. is a large telescope and probably would be happy
in a relatively permanent location, but is portable if
you have lots of trunk space. Loading into and out
of a car trunk is easier with two people. Can be
seen at the Fox Observatory. Asking $900 but
willing to negotiate. Contact John H. at
Still Available: 519-371-0670 or stargazerjohn@rogers.com.
- Orion 2x Deluxe Barlow (asking $135)
- Antares 2-inch filter 23A (light red) ($35)
- Antares 2-inch filter 80A (blue) ($35)
- LP-2 Narrowband filter (light pollution filter
for 2-inch eyepieces (asking $200) FOR SALE:
- contact stargazerjohn@rogers.com Celestron NexStar
- ALL OFFERS CONSIDERED
102GT Refractor
• High quality 102mm (4") refractor telescope with multi-coated glass optics.
• Computerized hand control with 40,000+ objects in its database and motorized altazimuth mount
• Special set of 5 eyepieces allowing you to view objects up to 250 times closer than the naked eye
• StarPointer finderscope to help with alignment and accurately locating objects
• Quick-release fork arm mount, optical tube and accessory tray for quick no-tool set up
• Sturdy stainless steel tripod and accessory tray included
• Includes TheSkyX First Light Edition Astronomy Software,
• which provides education about the sky & printable sky maps Asking $300. Item description is
• 2 year manufacturer warranty from Celestron website. Contact
• Requires 8 AA batteries (not included) Tim Keachnie at 226-434-2287 for
specific list of accessories.SGN Image of the Month August 2018 pg 13
Venus and 3.4-day-old Crescent Moon by John Hlynialuk
As editor of this newsletter, I try to limit how much I promote IMAGE SPECS:
my own images, but this is one I could not resist sharing. I
got more than a few comments when I sent it around to Canon 6D camera with 100-400 mm Canon telephoto lens at
members and one even prompted me to send it in to the the 400 mm setting. Focal ratio f/5.6, with ISO 6400 and
Starfest Photo Contest. Unfortunately I missed the deadline exposure of 1.6 seconds. I normally like to shoot at lower
by about 12 hours. Bummer. ISO like 4000 or so for dark sky images and for bright objects
like the Moon, I often set it to 200. But this time, the high ISO
The image above was taken July 15 at 9:48 pm, the evening helped to shorten the exposure so that nothing trailed
following the spectacular skies of Saturday night at the noticeably at the high magnification. The 500 rule says that a
BPNP Dark Sky Weekend (see pg 1 and 3) but as you can 400 mm lens should be exposed only for 1.2 s (500/400) to
see the skies here are a bit cloudy. Still, this time the clouds avoid trails. With a higher ISO I was able to get that up to
added a bit of ambiance to the photo and all I could say was almost 2 s to record the earthshine.
“wow” as I saw these appear on the screen.
As always, having the ability to pick the best settings after
The close approach of Venus and Moon will be repeated this trying many different ones without having to worry about
month but at 3 times greater separation. Separation between “wasting film” always helps. Gotta love those DSLR’s.
Venus and Moon in this image was a mere 2° and both fit
nicely into the frame at the 400 mm end of my Canon Once I got a consistent result, I took another 60 or so
100-400 mm telephoto. The whole image FoV is about 3.5°. consecutive images and put those into a time-lapse
sequence showing the Moon setting behind the trees on the
It took a little experimenting to get the exposure right, as I horizon below it. I will show that at the Aug 1 meeting of BAS
wanted to get some earthshine without having to overexpose at the Fox Observatory. Hope to see you there.
the image or get trails, -the clouds I’m sure helped make
that happen.You can also read
