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The Nacreous Oughts

27 February 2017


19 February 2017

Rhexergon 


No one could have been more excited than me to hear of the new exoplanet around Lalande 21185 (AKA HD95735 & GJ411). True, it is only a "hot Neptune" & technically not in the habitable zone (0.14-0.27 AU). But at 8.3 light years away, this makes it the second closest exoplanet to Earth.

What do we know of this world? It orbits in 9.8693 days (or a neat 1/37th of a year), & has a minimum mass of 3.82 (or 42/11) Earth's (0.012 Jupiter). With the star's mass being given as 0.46 (i had thought more like 0.31--), that puts it at 0.069509978 AU (about 1/14). That's pretty close-in...

So how hot is this "hot Neptune" anyway?? Using the parallax of 0."39342 & visual magnitude 7.520 (via Simbad), i get a visual luminosity for this "M1.5" star of 0.005524425636 (1/181) solar. Here's where it gets tricky. The stellar radius is given as 0.393 & its effective temperature 3838 K. In my frame of reference, that's more like a late K star--& solving for a fit on radius alone, i figure around BC -1.235 [M0.5] & 3375 K for 0.39 solar. I could figure out the Bolometric Correction they used from just that, but i happen to know that the resultant planetary temperature is relatively nondependent on these precise stellar factors. (It's different for the mass, though...) In short, i'm guessing it has a blackbody temperature of around 384 K (Venus is 328*)--less if it is figured as slow-rotating, with little atmospheric circulation (not according to our current ideas, especially for an exoplanet appreciably large than the Earth). Plugging in some hypotheticals (Albedo=0.6, Greenhouse effect=80) i get an average surface temperature of some 113 Centigrade. For water not to boil at this temperature (let's use 400 K), the pressure would have to be 1500 mm Hg, or 2.0 atmospheres (it is probably higher--but see below).

By other assumptions, i find a diameter of 11,370 miles 1.436 or about 102/71); a surface gravity of 1.852 (or 113/61) (=three-legged, rather than two or four); an escape velocity (1.63 or 31/19) fortunately below the amount needed to hold hydrogen or helium, so no "snowball effect" & Uranus-Neptune planetary structure. A recent study suggests that planets of red dwarf primaries will, in their early days, be stripped of much of their atmospheres by the intense solar wind of the pre-Main Sequence evolution. I haven't studied this issue deeply, but i think this means that smaller exoplanets close-in may be practically airless, while larger ones (which might otherwise have held too much atmosphere) could be reduced, but not eliminated--& perhaps actually made more "inhabitable" in the upshot. but this is all without looking at the numbers... Apparent size of its sun (assuming the clouds part): 5.6 the Sun as seen from Earth.

I call this planet "Rhexergon" after a character in Richard Horne's 19c epic poem Orion. De Camp's Ormazd (Rogue Queen) is the earliest naming of a planet in this system (Earth-equivalent). Latiffa (or Gatewood) is very near where we found this one. The ghost planet of van der Kamp & Lippincott (1951/74) was used by Hal Clement, as "Dhrawn", in Star Light.


(via)

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*Venus, of course, did not start out with its oceans evaporated & its carbon dioxide all released from the seas & crust, & from a temperature & chemical constitution not dissiilar to present-day Earth's, developed a runaway greenhouse effect, because a G-type sun such as our own grows appreciably brighter from its initial ZAMS (Zero-Age-Main-Sequence) state

Also: "Lalande 21185's sigil is two sides of a pentagram meeting in the top center point and a thin oval crossing them"

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26 December 2016

a sticky croak 


"Besides hard science, there is soft science, the science of shadow areas and story areas, and you do wrong to deny it the name." --R A Lafferty, "Cliffs that Laughed"

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25 October 2016

the botteghe surfers 


"Most of us believe that car accidents are caused by inept drivers. Not true!."

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10 October 2016

glossary to crawling buttress 

Jetztzeit (Walter Benjamin)- a moment when it is possible to change history
tekke- a Sufi lodge
tachypath (Peter Dickinson)- a morbidly fast driver
taisk- the voice of one about to die
Olentzaro (Basque)- ‘bad Santa’
teudib (Taneraic)- global warming
zipzygo (Peter Please)- impenetrable/ not yet
Sprachregelung- Nazi rules about what is & is not speakable
jark- a seal
floatpig- one kind of the simulated denizens in a certain defunct multiplayer online video game; a signifying typeface
megilp- a nondurable Victorian painting medium
CMALYBOI BISLI (Lojban)- ‘sleet’
frass- insect excrement
Jestocost- a character in Cordwainer Smith
Hadarac Desert- an imaginary place in Eragon
lanugo- an newborn’s down
Der Zor- what Armenians call their Holocaust (Peter Balakian)
qeh oube (Taneraic)- 'death worship'
crogor (Cornish)- ‘hangman’
arwedha (Cornish)- ‘signify’
X-sistemo- the convention of spelling Esperanto with an extra X or H after the letter, instead of using the diacriticals not found on a regular keyboard
khejzawul (Pashto)- ‘to lift, raise up, erect’
Rattenkrieg- ‘War of the Rats’ (Battle of Stalingrad)
Slovio- a Slavic-based auxlang
SuSmo’ jaqtaH (Klingon) ‘it is fluttering on the breeze’
jboku’ile- a name for a supposed Lojban/Ithkuil hybrid
Khurbn (Hebrew)- the Holocaust (Jerome Rothenberg)
aibeu iyoh (Taneraic)- 'new moon'
AZI AGIAR (Enochian)- ‘harvest’
kodokushi (Japanese)- ‘lonely death’
proplyd- protoplanetary disk
LI NI’U LU’O (Lojban)- the negative square root of -1
(La) Xagvar- imaginary, cosmopolitan city in Lojbanistan
gerkamenknockin (Golden Girls)- “the precise moment when dog doodoo turns white”
dyvocla (Cornish)- ‘unbuckled’
Totentanz (German)- ‘danse macabre’
AEpyornis- a giant, extinct, flightless bird
musjid- mosque
hadito (Esperanto)- ‘hadith’
haierious (should be “hareious”)- cruel
skimmington- charivari
Thekk- Odin
zimme (ghost word from Bulwer Lytton)- gem
Cynothoglys (Ligotti)- an evil god
drabal (Pashto)- ‘fallen, broken down’
conygry- rabbit warren
grypomachy- combat with griffins
droshky (Russian)- carriage

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30 September 2016

Nog Arapaho, lag aloha, paragon. 


(facebook five years ago)

Bunch appreciation.

A story that is the story of our failure to make a story, can only be told in terms of heroes & monsters.

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02 September 2016

Hercolubus 


(via space dot com)

So Proxima has a planet... Also known as Gliese 551 & HIP 70890, this dim red flare star (according to the paper, visual magnitude 11.05 at 1.295 parsecs--for a parallax of "0.7722, although Hipparcos gives 0.77233--), which is probably (but not certainly?) coeval with Alpha Centauri, with spectral type M5.5 V (3054 K), stellar mass 0.118 ⊙ (2/17) and observed radius 0.1410 (or 1/7th ⊙), appears to have a planet of at least 1.27 (about 52/41) ⊕ in a close, 11.186 (1/33 y.)-day orbit.

This works out to 0.048011508 or 1/21 AU, which for a visual luminosity of 0.00005553162797 (1/18008) & bolometric (BC at -3.60) 0.001528278072 (1/654), makes for a blackbody temperature of 252.3673234 of the planet. If its albedo & greenhouse effect are like the Earth's (0.36, 38K) then its average surface temperature is -9° C; if a little larger (say, 0.60 & 80), an average of 8° C is possible.


According to Li Zeng, a rocky planet with this mass should be about 1.083159015 (13/12) ⊕ in diameter (=8576 miles), & have a surface gravity of 1.083247851 ⊕ (at about the same density; a greater density is possible).

I call it "Hercolubus" because a cloud covered world of a star this cool would be red to our eyes. (Its inhabitants might be Hercolubozos.) --Certainly not Ad Astra or Furon...or even Meton. Discussions of its potential climates.

Though much has been said about this "red" sun, it is much bluer than candlelight (1400K); its energy is about 53% of our sun's & i would expect a leaf running on the same chemistry to be about twice as large as its Terran equivalent. Illumination-wise, the day would seem about 2% of ours (2/83), or about the same as a point in orbit between Jupiter & Saturn--brighter than "Pluto Time," at any rate.

Clocks are supreme on Hercolubus.


(Prague Astronomical Clock, via the aussie nomad dot com)

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