
Astronomers have found the stars responsible for an explosion recorded in 1437 - curtis
https://www.theatlantic.com/science/archive/2017/08/a-cosmic-whodunit/538482/?single_page=true
======
pmontra
My first reaction was "it shone for 14 days and only Korean astronomers
noticed it?" Then I googled for that nova and eventually found this
interesting article
[https://academic.oup.com/astrogeo/article/47/1/1.29/258488/W...](https://academic.oup.com/astrogeo/article/47/1/1.29/258488/Where-
have-all-the-novae-gone)

It seems that Koreans were particularly keen at looking for novae. Cloudy
skys, lack of fast global communications, the small number of people looking
for faint new stars could explain why nobody else noticed it. For example,
about the supernova of 1604 which was visible during the day:

> "On the 30th [of September], the sudden breaking of the clouds afforded one
> of Kepler's friends an opportunity of having a very short view of it… On the
> 2nd, 3rd, 4th and 6th of October, it was seen by several persons in
> different places. On account of cloudy weather at Prague, where Kepler
> resided, he did not see it until the 8th of that month."

If that's happened to a supernova, I can imagine a nova could slip away
unnoticed.

~~~
Keysh
This nova would also have been rather low in the sky. From Seoul's latitude,
the maximum altitude of the nova would have been about 7.5 degrees above the
southern horizon, and not visible at all from much of Europe.

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yawz
It always saddens me to remember that with the arrival of electricity &
technology we've truly lost the fascinating view of the cloudless night sky. I
assume that in 15th century Korea it was much easier to notice changes in the
night sky than it would be today.

 _(edit: typo)_

~~~
toomanybeersies
There are still several dark sky preserves
([https://en.wikipedia.org/wiki/Dark-
sky_preserve](https://en.wikipedia.org/wiki/Dark-sky_preserve)) in the world,
where the view will be just as good as 15th Century Korea.

Having spend several nights around Tekapo, which is one of the largest in the
world. I would definitely say that it's worth trying to spend a night in one.
The view of the night sky is stunning. You can see the Milky Way with the
naked eye, and the sheer number of stars is magnificent.

~~~
pythonistic
You don't have to go too far to find dark skies.

My wife and I rented a cottage at Sheep Dung just outside Boonville, CA, a few
years ago. Ukiah was on the far side of the hills to the east, another range
blocked the coast to the west, and the next closest big city was Santa Rosa --
far enough away not to cause light pollution. I got lucky because the Labor
Day wildfires were east of Clear Lake and blowing smoke east toward I-5. It
was the first time in my life I got to actually see the Milky Way with my own
eyes.

~~~
simonebrunozzi
I am in Bolinas right now, it's close to midnight, and I am going to close my
laptop in a few seconds, and go out to look at the night Sky - which I did
yesterday, and it was quite magnificent.

~~~
ars
Since you posted that 20 hours ago, I'm sure you're done by now. But don't
forget it can take 20 minutes to an hour to get your eyes fully adapted to the
dark.

So don't go out for just a short time, plan to spend a while in the dark
before fully enjoying the stars.

------
yeukhon
I got to say I am always astonished at astronomical discoveries. Finding a
wrecked ship in ocean is really really difficult, but correlate and finding
what is out there in the open space, hundreds or even more light years away is
like finding a dust particle in the open sea. Let's pause for a moment and
appreicate these discoveries....

~~~
senatorobama
And yet the average investment banker or lawyer gets 10x the salary.
Priorities...

~~~
hasenj
Astonishment factor is not worth much in terms of money.

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esseti
"Michael Shara and his researcher colleagues have spent the last nearly 30
years looking for the star responsible for this nova." that's what you call
dedication :D

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aerovistae
This headline is a little funny if you choose to read it as a legal verdict.

~~~
arcticfox
Good eye 11

~~~
aerovistae
30

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DrScump
It's grating to see a major publication quote a date as "1437 AD". It's either
"1437 CE" or "AD 1437".

~~~
eesmith
It may be a house style, and/or it may not be as important as you think.

For example, the Wikipedia house style, at
[https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Date...](https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Dates_and_numbers)
, "says: AD may appear before or after a year (AD 106, 106 AD); the other
abbreviations appear only after (106 CE, 3700 BCE, 3700 BC)."

The Atlantic is at least consistent.

"Pre-Islamic Iranian history is believed to range from about 4000 BC to 651
AD." \-
[https://www.theatlantic.com/international/archive/2012/04/ir...](https://www.theatlantic.com/international/archive/2012/04/iran-
before-islam-challenging-stereotypes-through-art/255503/)

"But earlier sand blows found underground have been dated—thanks in part to
the native pottery shards and charcoal that sandwich them—to 1450 AD, 900 AD
and 2350 BC." \- [https://www.theatlantic.com/science/archive/2016/06/the-
grea...](https://www.theatlantic.com/science/archive/2016/06/the-great-middle-
american-earthquake/486623/)

"The dawn of the "Neolithic revolution" around 8,000 BC marks man's transition
from hunter-gatherer to food producer. Life" \-
[https://www.theatlantic.com/health/archive/2013/01/the-
iron-...](https://www.theatlantic.com/health/archive/2013/01/the-iron-in-our-
blood-that-keeps-and-kills-us/266936/)

"...which killed about 50 million people in Europe and the Byzantine Empire
between 600 and 800 A.D..." \-
[https://www.theatlantic.com/health/archive/2015/09/disease-p...](https://www.theatlantic.com/health/archive/2015/09/disease-
plague-of-athens-ebola/403561/)

The one exception I found (I only looked at the first few matches) is due to a
book titled "EUROPE BETWEEN THE OCEANS: 9000 BC to AD 1000 " \-
[https://www.theatlantic.com/magazine/archive/2008/12/books-o...](https://www.theatlantic.com/magazine/archive/2008/12/books-
of-the-year/307162/)

------
mattbillenstein
"One the one hand" \- do these publications proofread their stuff?

~~~
InclinedPlane
Did you get a refund?

~~~
mattbillenstein
I did not, but I did swallow the ads they sent me so maybe I should.

~~~
Endy
So keep your adblocker and scriptblockers running.

~~~
quickthrower2
Except for the subjectively well written articles of course

~~~
Endy
What? No. Well-written or not, if they try to put ads and javascript in my
face, I block it.

------
pbhjpbhj
>"According to their calculations, the star was right in the center of the
nova shell on the day the Koreans saw a mystery star, which means it caused
the cosmic explosion."

Hmm, or it was in a different plane and is many light years from the nova and
some other star, which died, or is too faint to see, or isn't charted, was the
cause of that particular nova.

Isn't this classic "correlation is not causation" stuff?

I was expecting to find how they showed the Koreans recorded the position so
accurately it could be matched - to the day - with a projected location of a
star for which we have 3 data points?

The conclusion (in the abstract) sounds more like a postulate. It seems
perfectly reasonable, but does it really follow logically from this single
instance?

Presumably, if the conclusion is sound, there are enough records of novae that
one can now draw _many_ star trajectories through groups of novae each caused
by a single star?

~~~
pvg
_Isn 't this classic "correlation is not causation" stuff?_

It isn't. There are only a few dozen intragalactic novas per year. They've
been looking for this one for a while and so far this is the only candidate
anyone's found.

 _one can now draw _many_ star trajectories through groups of novae each
caused by a single star?_

That's a bit like saying you can draw many trajectories of cars that could
have been in a crash while the smoldering wreckage is sitting by the side of
the road.

~~~
pbhjpbhj
We're looking at 600 years back, so are you saying there's 18000 novas to
examine (30 per year) across that period?

Their conclusion in the OP was AIUI that _many_ stars produce novae serially.
So we should surely be able to match series of novae (along a stars
trajectory).

Do you know are English language details of the historic Korean record
available (are they in the paper)?

[http://www.cbat.eps.harvard.edu/nova_list.html](http://www.cbat.eps.harvard.edu/nova_list.html)
shows very few recorded novae, is this a listing including the dozens per
annum you mention?

~~~
sanxiyn
[https://arxiv.org/abs/astro-ph/0501331](https://arxiv.org/abs/astro-
ph/0501331) includes a table (as far as I know, exhaustive) of historical
Korean nova records.

~~~
pbhjpbhj
Fascinating, I was expecting it to be in hanguls rather than Chinese
characters - never really considered astronomy as having an overlap with
history quite so much as this before. Thanks for the link.

