Posted on 04/24/2019 11:21:38 PM PDT by SunkenCiv
They added three orders of magnitude (and several decimal places of precision) doing unit conversions.
The angular distance between the planet and its star is about 0.0005 degrees, or 1.8 arcseconds. Pluto is much smaller than that in a telescope. What is amazing is the ability to see the planet without it getting lost in the glare of the star. I suspect that this involved stacking lots of short exposures to get adequate dynamic range. Still amazingly sharp optics.
Far out AND solid...dude.
Looks like someone at the end of the street with a flashlight.......maybe a burglar?
Agree completely.
Add to that complexity the fact that the initial imagery is both raw data and electronic (CD image capture) and you add a lot of interference that needs to be filtered out.
Your point about many short exposures from separate observatories is probably a key factor in the discovery since, with a calculated 27,000 year orbital period, any reasonable observation period (expressed in fractions of a human lifetime) would, necessarily, encompass only a very short segment of a single orbit of the planet. Getting the planet to emerge from observational “noise” had to require massive computer processing followed by cross matching between the participating observatories to confirm they were really looking at the same distant point in space.
It really is a remarkable achievement.
(I assume that their initial interest in the star was it’s relatively young age (4.5 million years) and curiosity about what could be observed about early planetary formation within its accretion disc. The fact that there was already at least one discernible planet observable using the transit method probably came as a surprise.)
So, bring a sweater?
Since I am somewhat red/green colorblind, wonder if it would partially affect me?
Space is beyond huge. Think of it this way. what they are seeing was reflected light that came off a planet around 800 A.D. 600 years before colubus “ sailed the ocean blue”. Righht now that palnet couls be dust , hit by a huge meteorite and vaporized. but we wouldnt know that until 3219..
Jez, sorry about the misspelled words, I quit coffee, my shakey fingers are all over today.
I am not sure how they computed the period of the distant planet, but I am nearly certain it was not from angular measurements. If they have the period of the near-in eclipsing companion planet and can measure the associated Doppler shift of its star, they provides constraints on the size of the small orbit and therefore mass of the star. Knowing mass of the star and distance to the planet one can estimate the period of a circular orbit.
So what are we seeing? Is the planet the big white globe in the middle or the white dot at 10:30?
Can’t hurt but, at - 386 degrees Fahrenheit (surface temperature of Pluto), you’d better make sure your spacesuit heater is working properly.
It’s the little white dot at 10:30. Don’t feel alone in being uncertain about what was referred to. I thought it was the big pale blue dot until I checked the article for further details. It’s circled in the image in the article so the reader won’t miss it.
In 13,500 years it should serve as a strong signal that it's happy hour!
27,000 years is the number reported in the article.
Even assuming observation from above or below the orbital plain, an orbit that large would be difficult to discern from a straight line over a short period of observation. So your surmise concerning fitting observed data to theoretical orbit calculations makes sense. Once, that is, you believe you are actually dealing with a planet in orbit.
Small as it appears, how big would that planet have to be to register as an image of (?) pixels from 1200 light years away?
Its just a light blob moving around really really far away from us but until we can decide on what it actually is we are calling it an “exoplanet”. We thought we spotted a single cell life form but the triggering caused by the recapture of the escaped neutrinos caused an automatic voluntary spontaneous abortion of the viable fetus. The host being’s mental well being has been compromised and now we must send trillions of dollars in compensation to the host beings for their fragile mental well state lest they will become the largest irritant in the known galaxy.
660 AUs is more than 1% of a light year.
To the naked eye, those planets are outta sight!
From that outer planet its own star would probably look about like any other star. Whoa!
Good question. In professional telescopes and other professional optics pixel pitch (pixels per millimeter) are matched to optical resolution. The resolving power of an optical system is in radians is:
ds = 1.22 x wavelength / aperture
where:
ds = resolving power in radiansFor the Hubble Space telescope that works out to about 2.29 x 10^-7 radians. The resolution at 1200 light years would be about 2.6 billion kilometers or 17 AU. For two objects to be resolvable to the HST at that distance they would have to about 17 times the distance between the earth and sun apart.
1.22 = empirical constant for a circular aperture
wavelength = optical wavelenth, use 550 nanometers for visible light
aperture = objective diameter in the same units as wavelength.
At the distance to Pluto (40 AU) the resolution of the HST is about 1375 km about half the diameter of Pluto, 2377 km. Pluto would occupy four pixels, two horizontally, two vertically, in the HST.
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