The Greatest discoveries by amateur astronomers
The very first amateur astronomer equipped with the very first amateur telescope was
sir Galileo Galilei. He pointed his small
instrument towards the sky, and he discovered Jupiter's moon system.
Nowadays technology has improved and with more amateur astronomers being equipped with larger
instruments, along with the increasing amount of High-resolution survey data being released
to the public online, amateurs are playing an important role in the scientific community.
In this video, we will take a look at the most important discoveries made by
amateur astronomers all over the years! Perhaps you will recognize some of them!
0:46 The first one is the Soap Bubble Nebula. It is actually a planetary nebula, and before
2008, nobody noticed that, essentially because it lies near a much much bigger and brighter object,
known as Crescent Nebula. Astronomer Dave Jurasevich,
randomly found the object when imaging the sky using his 160 mm refractor
f/7.7 and a 6nm Hydrogen Alpha filter. After that, astrophotographers and astronomers all over the
world have been amazed by the Soap Bubble Nebula, and have captured it for their own collections.
However, if you are an amateur astronomer you need a lot of effort to make the discovery official.
That's why Dave defined this discovery as a “blessing and a curse”.
It took Dave months to look over every known catalogue, amateur photos,
forums and even literature to make sure the bubble wasn't previously discovered.
After many reports and emails with the IAU, his discovery was made official.
In 2013, 5 years later, the world reference database for the identification of astronomical
objects, located in Strasbourg, gave Jurasevich's Soap Bubble Nebula the designation of "Ju1".
We can appreciate in this picture the features of both the crescent nebula and soap bubble nebula.
The Soap bubble is the smaller object on the left side.
These clouds of gas and dust drift through rich starfields along the plane of our Milky Way Galaxy
toward the high flying constellation Cygnus. Both were formed at a final phase in the life of
a star. Also known as NGC 6888, the Crescent was shaped as its bright, central massive star, which
shed its outer envelope in a strong stellar wind. Burning through fuel at a prodigious rate, the
star is near the end of a short life that should finish in a spectacular supernova explosion.
Instead, the Soap Bubble Nebula is a planetary nebula, the final shroud of a lower mass,
long-lived, sun-like star destined to become a slowly cooling white dwarf. While both are
some 5,000 light-years or so distant, the larger Crescent Nebula is around 25 light-years across.
We said the Soap Bubble Nebule is a planetary nebula. But what does it mean?
A planetary nebula is a type of emission nebula consisting of an expanding,
glowing shell of ionized gas ejected from red giant stars late in their lives.
The term "planetary nebula" is a misnomer because they are unrelated to planets.
The term originates from the planet-like round shape of these nebulae observed by
astronomers through early telescopes. The first usage may have occurred during the 1780s with
the English astronomer William Herschel who described these nebulae as resembling planets.
Though the modern interpretation is different, the old term is still used.
All planetary nebulae form at the end of the life of a star of intermediate-mass, about 1-8 solar
masses. It is expected that the Sun will form a planetary nebula at the end of its life cycle.
They are relatively short-lived phenomena, lasting perhaps a few tens of millennia,
compared to considerably longer phases of stellar evolution.
Another important discovery made by an amateur was the one of Comet Lovejoy.
It was also nicknamed “The Great Comet of Christmas 2011” since we best observed it
between November and December of that year. Comet Lovejoy was a magnificent comet
that peaked at magnitude -3, and although very difficult to see with the naked eye,
due to its proximity with the sun, it was a beautiful target for astrophotographers.
Comet Lovejoy was named after its discoverer, Terry Lovejoy, from Australia.
Actually, this was not the first time Terry discovered a comet.
It was actually the third one! And the thing is....he never stopped!
He kept going hunting and finding comets all over the years.
As of today, he has discovered 17 comets. However, his most famous one, Comet Lovejoy,
was found using a 7.9" Schmidt-Cassegrain telescope and a CCD camera.
In the days between the discovery and the transit to the perihelion,
an observation campaign was conducted in the southern hemisphere aimed at characterizing
Comet Lovejoy, considered of interest because it is much larger than the other grazing comets
usually discovered through the Solar and Heliospheric Observatory space telescope.
In particular, the estimation for the diameter was from100 and 200 m.
As such, the comet may not have survived the perihelion transition, which would have seen
it pass through the solar corona. But guess what? The comet transited on December 16 about 140,000
km from the solar surface, surviving the event. This suggested that the dimensions of the core
are larger than previously assumed and that it could even reach 500 m in diameter!
It was a huge comet! At its maximum,
it reached a magnitude of -4, which means it was almost as bright as Venus. As such,
it is the brightest grazing comet observed through SOHO.
So far, we talked about Nebulae and Comets. Now I want to ask you: do you know what
Strömgren sphere is? The definition is quite complicated, but...it's all that we have!
Hot, young stars emit radiation that ionizes the surrounding
ISM. The Strömgren sphere is defined as the spherical volume of this HII (H second) region
where the rate of ionizations balances the rate of recombinations.
What if I told you that an amateur astronomer discovered one of them?
Would you believe me?
Well, you should, because it happened.
Lionel Mulato, a French amateur astronomer and astrophotographer, is really one of a kind.
He was the discoverer of ten planetary Nebula candidates using optical images and mid-Infrared
images from satellites. His first find Mul 1 was an elongated nebula in Sagitta,
discovered accidentally when taking images of the Necklace Nebula, another Planetary Nebula!
Lionel described it as "a little ball of Hydrogen Alpha" that was
visible on his camera after a 20 min exposure with a filter.
He was really excited, but astronomers have to be careful with the excitement.
You have to check it is not an artefact.
That's why Lionel imaged the area again the next day, and once again saw what
seemed to be an unknown deep sky object. Mulato contacted a planetary nebula expert
at the Observatory of Strasbourg to ask if it was a new discovery,
and the expert confirmed! It was named Mul 1. The object now is not thought to be a planetary
nebula, but instead a Strömgren sphere, meaning ionized gas around a very hot star. An example of
a famous Strömgren sphere is the Rosette Nebula. Similarly, Mul 4 and Mul 5 were discovered.
Mul 4 appears stellar in Lionel's stellar images, but professional images were taken by the NOAO
(National Optical Astronomy Observatory) definitely indicate the object to be
nebulous in nature. Mul 5 appears as a blue elliptical nebula in both Lionel’s images
and in online survey images. While Mul 5 has been confirmed to be a true Planetary nebula,
the nature of Mul 1 and Mul 4 are a little less certain.
Now ladies and gentlemen, fasten your seatbelts. You won't believe what Dan
Petersen discovered in 2012. He was basically just chilling out,
observing Jupiter on September 10, 2012. All of a sudden, he saw what looked like a
fuzzy ball colliding with the planet. He thought he was dreaming.
Maybe it was just a figment of his imagination. Dan asked other astronomers on a forum about
the strange phenomena, hoping he was not the only one to spot this.
Not only did he get a confirmation that someone else had seen it, but he also received a video!
George
Hall, a keen photographer of Jupiter, captured this video.
He absolutely loves taking pictures of the solar system's largest gas giant. He reviewed
his files from that night, where he used a 12" telescope and a monochrome camera to capture it.
George basically became famous among the scientific community, in no time!
He received so many e-mails, inquiring about the accuracy of the time stamp,
the image acquisitions, and a copy of the raw file for deeper study. During the week,
he also got hundreds of calls from magazines, news channels, and blogs from all over the world.
The 2012 impact was not the first one seen to happen on another planet.
Comet Shoemaker-Levy 9 was the first comet to be observed during its fall on a planet.
Discovered on March 25, 1993, by the astronomers Eugene and Carolyn S. Shoemaker and by David Levy,
analyzing photographic plates of the surroundings of Jupiter, it immediately aroused the interest
of the scientific community; in fact, it had never happened that a comet was discovered in
orbit around a planet and not the Sun. Captured between the second half of the 1960s and the early
1970s by Jupiter, the interactions between the gas giant and the comet had caused it
to disintegrate into 21 smaller fragments. Did you know that Jupiter has been called
the vacuum cleaner of the solar system? That's because its gravity sucks in asteroids and
comets, protecting us from those objects. But it's not all good: Jupiter's gravity can also nudge an
object onto an orbital collision course with Earth! Luckily, nothing bad happened so far...
Last but not least, we want to mention the amazing discovery of the Giant Squid Nebula.
It is also named "Ou 4", after its discoverer: Nicolas Outters.
Ou 4 is the fourth nebula discovered by Nicolas and by far the most impressive one.
Nicolas' plan was to take pictures of the Flying Bat Nebula,
in order to try out his new astronomical filter for the very first time.
Having taken exposures over several nights, Nicolas realized that a large nebulous cloud
was visible on his OIII frames only. He sent an e-mail to Agnès Acker,
a planetary nebula specialist at the observatory of Strasbourg. He said that
The shape looked like a bipolar planetary nebula and it was only visible in OIII,
no trace of it AT ALL in Hydrogen Alpha a or SII.
Guess what? Agnes confirmed his discovery. Since the discovery, other amateur
astrophotographers all over the world have frequently used OIII filters to image the
area to capture the beautiful Ou 4. Here's a fantastic image of the Giant Squid Nebula.
We don't know pretty much about it, because it's a hard object to study.
The true distance and nature of the Squid Nebula have been difficult to determine.
A recent investigation suggests Ou4 is actually located around 2,300 light-years away from the
solar system. If this is the case, then Ou4 would represent a spectacular outflow driven by HR8119,
a triple system of hot, massive stars seen near the centre of the nebula,
and the truly giant Squid Nebula would physically be nearly 50 light-years across.
"This video ends here! Thanks for watching everyone! What's your favourite amateur discovery?
Are you an amateur astronomer, or an astrophotographer? Let us know in the
comments below, be sure to subscribe, and I'll see you next time on the channel!"