[HN Gopher] An asteroid will occult Betelgeuse on December 12th
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An asteroid will occult Betelgeuse on December 12th
Author : belter
Score : 231 points
Date : 2023-11-18 21:51 UTC (1 days ago)
(HTM) web link (www.universetoday.com)
(TXT) w3m dump (www.universetoday.com)
| theoreticalmal wrote:
| Occlude? Lol
| cwillu wrote:
| "The term is often used in astronomy, but can also refer to any
| situation in which an object in the foreground blocks from view
| (occults) an object in the background."
|
| https://en.wikipedia.org/wiki/Occultation
| dylan604 wrote:
| You might want to become familiar with the use of the word as a
| verb instead of a noun. It might make you look less than
| whatever this makes you look.
| jjtheblunt wrote:
| Mention of occlude refers to the presumed typo "occult" in
| the title. Understandable question, given occlude and occult
| both work there.
| dfc wrote:
| If seems like the right thing to do is to look up "occult"
| in the dictionary instead of leaving a two word comment
| like "Occlude, LOL."
| ajkjk wrote:
| Of course, but it takes two seconds to find out that it's
| not a typo.
| jjtheblunt wrote:
| Yeah agreed, though the lol person obviously overlooked
| that!
| dylan604 wrote:
| It's funny to me that you still think it's a typo. There's
| still time to retract this
| giantrobot wrote:
| Evacuate? In our moment of triumph?
| jjtheblunt wrote:
| I dont: i think the person who wrote lol presumed it was,
| as i said.
|
| Fwiw i had several years of Latin so the etymologies in
| this case are kinda fun.
| Apocryphon wrote:
| Beetlejuice, eh
| eyelidlessness wrote:
| Beetlejuice
| dylan604 wrote:
| Beetlejuice
| jihadjihad wrote:
| Occult and occlude are very similar, but they actually do not
| share a similar etymological origin. Occlude could definitely
| be used here, but the more appropriate astronomical word would
| be occult.
|
| The etymological sense of occlude is that of closing
| off/blocking, while occult is covering/hiding.
| MBCook wrote:
| Thanks. I've never seen the word occult used like this, your
| explanation was helpful.
| thaumasiotes wrote:
| > The etymological sense of occlude is that of closing
| off/blocking
|
| That's quite the sense development for _include_ , which I
| see derives from a word meaning "shut in, imprison".
| denton-scratch wrote:
| "Occlusion" is also used in medicine, to refer to some tube
| or passage in the body becoming blocked.
| kristopolous wrote:
| There's another article I was reading last week about this
|
| https://skyandtelescope.org/astronomy-news/asteroid-will-cov...
|
| It's really stunning how much information can be gathered from
| such an event.
|
| All this knowledge merely from our single planet by tiny
| variations of measurements in finely calibrated instruments as if
| you were able to map out the city of Paris confined to the
| observations from a single window.
| elesiuta wrote:
| Great article, I've always been impressed by this too. It's
| neat that it sounds like even amateurs with nothing but a
| regular DSLR can contribute to this as well.
|
| > By precisely timing the duration of the occultation from many
| sites simultaneously, they can refine their knowledge of the
| size and shape of the asteroid.
|
| > Betelgeuse is the 10th brightest star in our skies (+0.5
| magnitude), so observers need only modest equipment to
| participate.
|
| > the easiest way to capture the event is to use a simple DSLR
| camera on a tripod ... video frames must have a short (few-
| millisecond) exposure time ... Millisecond accuracy timing is
| crucial ... [an app] for timestamping occultation observations
| is called Occult Flash Tag (Android) or AstroFlashTimer
| (iPhone)
| kristopolous wrote:
| I can imagine it helps to normalize the various perturbations
| from atmospheric non uniformity which may be able to help the
| higher quality measurements decrease the noise.
| nsajko wrote:
| > Occult Flash Tag (Android)
|
| Sadly this seems abandoned and it seems to have been removed
| from the Play Store. It's also not on F-Droid, even though it
| does seems to have a Git repo on Github.
| Razengan wrote:
| > _All this knowledge merely from our single planet by tiny
| variations of measurements in finely calibrated instruments as
| if you were able to map out the city of Paris confined to the
| observations from a single window._
|
| Indeed, but I like to wonder how much of it will turn out to be
| wrong when (if) we finally get to visit it in person.
|
| I mean, do you really want to believe that everything about
| something as practically infinite as the UNIVERSE could be
| learned from just a single planet in a few hundred years?
|
| Because that would be pretty boring. :)
| doctorwho42 wrote:
| Well as a physicist I think it's safe to say this, of course
| you can't know everything from a single solar system. Most of
| the stuff we see/measure is massive, and the smaller stuff
| like exoplanets is general.
|
| What we are doing now is like squinting while looking around
| a busy city street. You can get a sense of the cars, the
| people, etc. but you can't tell me exactly what the sign
| across the street says or what the hours for street parking
| are for that spot across the street and down two cars.
|
| And the real interesting thing to us as living beings is
| other living beings/organisms no matter how different. And no
| matter the quality of your telescope or detectors, you are
| never going to be able to resolve anything that far away nor
| with any degree of certainty. So from the limits of physics,
| we know we are going to eventually need to get down from our
| windowed apartment and start walking the streets of Paris.
| For no matter how long we stare, we will never truly know the
| smell of the bakery a few streets over until we walk through
| it's door.
|
| And to those that say robotic missions are the only true way,
| they are missing out on the truly human and sentient reason
| to go. Through individual experience we can create more than
| just new knowledge, we can expand upon the human experience
| as well as create new art to share those experiences.
| kristopolous wrote:
| You know those pictures of a spiral galaxy that say "you are
| here?" pointing to the outer edge.
|
| You actually aren't. That's not our galaxy, we don't have
| pictures like that of our actual galaxy and don't have any
| idea how to get one.
|
| Also there's tons of other fundamental limits - galaxies that
| will likely forever be just faint pixels, the distribution of
| photons being too dispersed for any detector.
|
| Also there's the light horizon problem - we can only see to
| what the age of the universe allows, not necessarily to its
| extent.
|
| Beyond that let's say there's a 100% confidence of methane on
| a planet around one of the Alpha Centauri stars, say Proxima
| Centari B, a pretty solid indicator of life. Ok now what?
|
| Probes like Voyager would take 75,000 years to get there. If
| we had loaded a ship with neanderthals during paleolithic
| times, their descendants would just be arriving now. Even the
| much touted solar sails would take 25 years to get there and
| 4 years to send back any data. If magically launched
| tomorrow, it'd be 2052 before first byte. The distance is
| really wildly insurmountable and that's just our next door
| neighbor.
|
| If I could time travel say, 25,000 years hence and we somehow
| had not blown ourselves up, I could imagine even then asking
| "how much of space have you explored" and getting an answer
| like "well, the milky way is 100,000,000,000 stars and
| 100,000 light years across so about 0.001% of that." There's
| ballpark a trillion galaxies btw. At some point, the numbers
| become meaninglessly large, might as well just call it a
| zillion.
| teo_zero wrote:
| You know those signs with the city map with an arrow saying
| "you are here"? Most of those are drawings, not
| photographs. So what?
|
| Just because we can't take a picture with a camera,
| shouldn't we build a model of something?
| kristopolous wrote:
| ceci n'est pas une pipe
| grammers wrote:
| I find it amazing what science can do nowadays. Makes you
| wonder where we're going to be in one hundred years from now!
| belter wrote:
| This is actually a much better article. @dang can we update the
| link to the one above?
| dylan604 wrote:
| I'm never unimpressed when we can make these kinds of advanced
| notices. I know it's just math, but there's a lot of objects out
| there to run all of the simulations against to see what will be
| where when while in our line of view.
| Jerrrry wrote:
| All stars are fixed point-like, basically static coordinates,
| so it's more of when one object encroaches another within a few
| micro-degrees.
|
| 3-body problem implies crazy perturbations and chaos theory and
| invoking of pendulum analogies, and all that's true, but due to
| the magnitudes of difference between human timescales and
| cosmological, we know the eclipses, occults, and all other
| matter of quirky alignment and other miscellaneous minute for
| millennia to come.
| nonethewiser wrote:
| I can't quite put my finger on why, but it blows my mind that
| its that "simple" in the sense that all the factors can be
| accounted for despite being incomprehensibly far away. My
| instinct is that there would almost certainly be some tiny
| unaccounted for perturbation that throws everything massively
| off over huge distances yet that's not the case.
| TuringTourist wrote:
| I can guarantee "simple" comes at the cost of (probably)
| multiple tens of thousands of pages of thrown away scratch
| paper (or equivalent) over many years and lives.
| Jerrrry wrote:
| It is, it is just so far into the future that it seems
| trivial.
|
| The Voyager spacecraft, when being gravity assisted by
| Jupiter, stole enough energy from it, that in 5 billion
| years, Jupiter will be 2 millimeters behind in its orbit
| around the sun.
| ben_w wrote:
| All the stars we can see with our naked eyes are close enough
| to that, yes.
|
| But you did make me think of this:
| https://www.eso.org/public/videos/eso1825e/
| dylan604 wrote:
| it's interesting seeing all of those stars in such random
| orbits instead a unified orbit where everything is going in
| the same direction. That one star really looks to be
| moving, and is pretty much the only way to know where the
| "center" is. Everything else looks like blobs floating in a
| petri dish.
| cdelsolar wrote:
| I've been looking for a resource for a long time but haven't
| found much. What I am curious about is how people 500+ years
| ago predicted solar / lunar eclipses (for example). Columbus
| was able to persuade some islanders that he was some sort of
| god by making the moon darken/turn red at a predicted time
| due to an almanac he happened to have.
|
| Would I be able to make the same prediction using only math
| and whatever instruments could measure the positions of the
| sun and moon that accurately? What instruments and equations
| do I use?
| fluoridation wrote:
| If you're starting from scratch you would need some way to
| determine the apparent position of the Sun and the Moon.
| Probably some kind of long tube that you can rotate
| precisely. Ancient people would use buildings for that
| purpose. Then you need to make observations probably over
| several, possibly many, years to determine the Earth's
| perihelion and apohelion (at least their timing), the
| length of the year, and the precession. For the Moon you
| determine its orbital period and plane, and if you want to
| know whether the eclipse will be partial or total from a
| given location you also need the perigee and apogee (again,
| at least their timing).
|
| Once you have all the data you find all the times when the
| Moon crosses the ecliptic plane (about once every 14 days),
| which are the only times when eclipses can happen. You
| discard the times when the Moon will not be aligned with
| the Earth and the Sun. You will be left with a handful of
| times per year when an eclipse is possible. If the eclipse
| is solar you compute the orientation of the Earth to see
| where it will be visible from. It's all trigonometry and
| linear algebra.
| Miiko wrote:
| My understanding is that at Columbus time they did not
| measured sun / moon positions, but instead based their
| predictions on the eclipse cycles - if you have long enough
| record of past eclipses, you can notice that they are not
| random but the same timing sequence repeats after some
| time:
|
| https://en.wikipedia.org/wiki/Eclipse_cycle
| Obscurity4340 wrote:
| What are the odds we have a repeat of a substantial celestial
| object hitting Earth? Like devastatingly so, can that be
| quantified in some sense?
| BurningFrog wrote:
| We have the (incomplete) track record of hits from the last
| billion years or so to extrapolate from.
|
| Don't know that there has been much since that Dino Doom Rock
| 65m years ago?
| dylan604 wrote:
| Ever see notices of an asteroid making it's closest approach?
| Sometimes, those are closer than the moon is to earth.
| Sometimes, they're further out. There does exist a team
| tracking objects for the sole purpose of deciding if there is
| a potential of a collision path.
|
| https://eyes.nasa.gov/apps/asteroids/#/home
|
| Has some fun graphics to show what we know about. The scary
| part are the ones we don't know about. Some say that this
| groups budget is not enough.
| fallingknife wrote:
| > An event like this is quite rare where the light from a bright
| star is blocked (or occulted) by an asteroid happening every few
| decades at most.
|
| > a previous occultation of Leona in September 2023
|
| Seems contradictory. Do they mean rare for any given star?
| makomk wrote:
| From what I can tell the star that it occulted in September was
| much too dim to be visible with the naked eye, whereas this is
| one of the brightest and most easily visible and distinctive
| stars in the night sky.
| xorbax wrote:
| If you're accepting a dim star only visible through space
| instruments I imagine it happens near-constantly
|
| Having it happen to a star you're actually aware of and can
| see tonight is pretty cool
| svat wrote:
| The key word is "bright". It's clearer in the other article:
| https://skyandtelescope.org/astronomy-news/asteroid-will-cov...
|
| > _An occultation of a 1st-magnitude star is rare -- such an
| event is visible from Earth only every few decades_
|
| and
|
| > _That changed on September 13, 2023: In advance of the
| December event, Leona occulted another object, this time of a
| 12th-magnitude star._
|
| It makes sense: there are only a few bright (1st-magnitude)
| stars so occultation of them is rare, while there are a lot of
| stars in the sky so occultation of _some_ (dim) star is not
| very rare.
|
| --------
|
| Edit: We can come up with a more explicit expression. If each
| individual star has an occultation once every k days, then "at
| least one of N stars" has an occultation roughly once every
| 1/(1-(1-1/k)^N) [?] k/N days. So if with N=22 (the number of
| 1st-magnitude stars:
| https://en.wikipedia.org/w/index.php?title=First-magnitude_s...
| ) this is once in 40 years (say), then with N = 10000 stars
| you'd see about once a month.
| murphyslab wrote:
| And there is already at least one other set of observations
| reported on arXiv from a September 2023 occultation. It's quite
| interesting, since the observations are a citizen science effort,
| with different observers from across Spain and Portugal (in this
| set) collecting data from multiple observers in multiple
| locations in order to map out the entire occultation. Part of the
| motivation was because of the upcoming Betelgeuse occultation and
| the potential to learn more about Betelgeuse from the
| observations:
|
| > The stellar occultation by (319) Leona on 13 September 2023 in
| preparation for the occultation of Betelgeuse
|
| > This represents an extraordinary and unique opportunity to
| analyze the diameter and brightness distribution of Betelgeuse's
| photosphere with extreme angular resolution by studying the light
| curve as the asteroid occults the star from different points on
| Earth and at different wavelengths. Here we present observations
| of another occultation by Leona on 13 September 2023 to determine
| its projected shape and size in preparation for the December 12th
| event.
|
| [1] https://arxiv.org/abs/2309.12272
|
| (Amazing that it was posted ~8 days after the observations were
| made!)
|
| The Occultation folks had a presentation on these preparations
| back this summer:
|
| https://occultations.org/publications/rasc/2023/2023Dec12Leo...
|
| https://www.youtube.com/watch?v=ok7hJ_2DPhM&ab_channel=IOTAA...
|
| It's also worth noting that if you're in a position to observe
| the occultation of Betelgeuse in December, you can and should
| participate. You need a DSLR camera in video mode for the light
| curve and a smartphone (recorded before and after) to accurately
| mark the time.
| gentryb wrote:
| Zaphod would be quite happy.
| wyldfire wrote:
| How do they determine when it's an eclipse, occult, or transit?
| pvg wrote:
| second paragraph here
|
| https://en.wikipedia.org/wiki/Occultation
|
| describes them all. Occultation completely covers the object,
| transit doesn't, eclipse requires a shadow.
| thenoblesunfish wrote:
| I don't immediately see how you distinguish an eclipse and an
| occultation. If (visible, say) light from some source is
| blocked by an object, isn't that a shadow (albeit a very very
| faint one)?
| ahmedfromtunis wrote:
| The fact that our species is capable of doing stuff like this
| with math is the biggest gift handed to us by evolution.
|
| That said, the thought that an asteroid passed between us and the
| moon is a stark reminder at how fragile we are. I hope I'll find
| photos of this on Google.
|
| But if that asroid hit the earth, would've that marked the end of
| mathematics or does it just exist independent of our neurons?
| spurgu wrote:
| Math is just a language for describing concepts that exist
| inside of our minds.
| eskaytwo wrote:
| for checking this sort of stuff, Stellarium is amazing open-
| source doftware.
| cushpush wrote:
| Square... roots
| albeebe1 wrote:
| Fun fact, that's Bob Barkers 100th birthday
| dclowd9901 wrote:
| I'm guessing you googled the date or asked chatgpt for
| significant markers of the date, but I would choose to believe
| you just know this for some reason. The world needs whimsy.
| wes-k wrote:
| And my 38th! Thanks for reminding me that me and Bob share it!
| uptownfunk wrote:
| Betelgeuse falls under the "Ardra" nakshatra constellation in the
| eastern astronomical systems.
|
| Q- is that the same day we will see it? I'm assuming the
| occultation is sufficiently close that speed of light
| considerations don't have a material significance.
| cvoss wrote:
| I didn't find any precise numbers, but the asteroid's orbit
| ranges from 2.5-4 AU out from the Sun. That puts it between
| 1.5-5 AU from Earth. Given that the event will be seen at
| night, it must be on the somewhat closer side currently. Even 5
| AU is less than 42 lightminutes.
| xorbax wrote:
| It's mildly distressing that only 5 AU is 42 light minutes
|
| The speed of light is pokey, astronomically-speaking. It's
| like existence functions via telegraph in 2038, and everybody
| has to Google Morse tables
| FredPret wrote:
| Give the simulators a break, maybe they haven't filled
| their universe with computronium yet!
| jonsolo wrote:
| I never expected I'd come to HN to learn about the study of the
| occult. TIL indeed.
| InCityDreams wrote:
| 'Occult' just means hidden. Where I am the .gov tests for
| 'occult blood in stools' of all people over 55, every two
| years. That's socialism, i guess, but i still do a double-take
| when i get the letter.
| thenoblesunfish wrote:
| For the lazy, is there a map already available somewhere which
| shows where on Earth this will be visible?
| IvyMike wrote:
| Available here:
| https://cloud.occultwatcher.net/event/1075-319-83995-648466-...
| thenoblesunfish wrote:
| Narrower than the ones we're used to seeing for eclipses!
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