Cosmic Evening, UUCB retreat 2000-05-05
Cosmic Evening, UUCB retreat 2000-05-05, Neal McBurnett
http://bcn.boulder.co.us/~neal/astro/
We often dream of travelling the world and seeing its many wonders,
but few people have the time or money to see much of it. Even though
the distances are much greater, astronomy is more accessible than
geography: half the universe is visible on any clear evening, and you
can look at most of it in one night.
The universe is easy to observe, dynamic, deeply related to our
existance (the hopfully-familiar story of the big bang and creation
and supernovae creating the elements that our bodies are made of.)
Outline of Evening
moon, mars
orientation info, constellations, big bang
watch Mir satellite go by 21:50
double star, colors
Sunset 20:00, civil twilight 20:30, nautical 21:06, astronomical 21:46
Moon: sets on a flat horizon at 21:58, but much earlier against the mountains
new moon was less than 2 days ago (on May 3rd at 22:13 MDT)
Mars: sets 21:20 on a flat horion, in Taurus
Constellations - Big Dipper, Leo, Bootes, Gemini. Lyra, Cygnus rising
Sky is 3-D!
Summer Triangle: Deneb (Cygnus) Altair (Aquila) and Vega (Lyra)
Sky is 3-D! Vega, 25.3 light-years away. Deneb, not quite as bright,
perhaps 1500 or 3000 light-years distant. Assuming the former,
3400 times brighter. Would be mag -7.5 if it were 10 LY = ten times
brighter than Venus. Would be mag -9.3 at distance of closest star.
2.7 degree K cosmic microwave background radiation from the Big Bang
comes from all directions
Relative to other stars, on average, sun moving towards Vega:
19.4 km/s towards 18:07, +30. nadir: 6: -60, below orion
Relative to big bang = apex : l=264.7+-0.8; b=48.2+-0.5, speed: 369 +-11 km/s
==? 10h dec -20deg, in Hydra, below Leo
Milky Way is low on horizon - catch it in the west early on, later in the north
Light pollution - big problem. Please don't let lights shine skyward.
Most stars in the sky are double stars!
http://www.cyburban.com/~mrf/a_doublestars.htm
Gamma and 11 Ursa Minor (far end of little dipper) great naked eye contrast
Name Sep. Mag. Spectral types Color Indices Difference
g + 11 UMi ~17' 3.0, 5.1 A3II-III, K4III .05, 1.37 1.32
mu Cepheus, (below house shape) very red, perhaps biggest visible
(size of saturn's orbit)
Hubble Deep Field above handle of dipper, Dec 1995, width of a dime at 75 feet
10 days (or 100 hours?) 5 square arc-minutes, 1317 cataloged galaxies
60 of these fields could fit in a square the size of the distance
between gamma UMi and 11 UMi. 30 million in the sky.
http://merlin.alfred.edu/~ast300/papers/potter/
galaxy 164 near center: RA 12 : 36 : 48.58 Dec 62 : 13 : 3.59
137: ra 12 : 36 : 48.22 dec 62 : 14 : 13.4
http://astrowww.phys.uvic.ca/grads/gwyn/pz/hdfn/index.html
table: http://astrowww.phys.uvic.ca/grads/gwyn/pz/hdfn/HDFNpzmag.dat
mag B=20-33 - many at 26
Southern Deep Field is located in the direction of the constellation
of Tucana, on the side of the constellation closest to the south
celestial pole.
Nearby stars with planets. See 1998-12 Sky&Telescope p. 54 for habitability
Tau Bootis: middle of three in bottom right of Bootes.
Period 3.3 days, 3.6 times heavier than Jupiter,
Star: 49 ly away, F7 star (sun-like)
1999-12-15, journal "Nature":
Probable detection of starlight reflected from the giant planet Tau Bootis
47 Uma >2.4 Mjup, 1.7 Lsun, about 1.5 times the insolation of the Earth
Upsilon Andromadae
16 CygniB >1.7 Mjup, 1.4 Lsun, between 0.6 and 2.2 times insolation of Earth
Rho Corona Borealis
51 Peg
Stars that you can watch move around each other over the years:
Name Mags. Sep. PA Period Comments
MlbO 4AB Sco 6.1, 7.6 1.7" 245 42.2 K4V in 2010, PA delta 50
=>chi UMa 4.3, 4.8 1.8" 273 59.8 G0V, G0V in 2010, PA delta 80
Kr 60 Cep 9.8, 11.5 3.0" 130 44.5 Red dwarfs
S1785 Boo 7.6, 8.0 3.3" 174 155 K6, K in 2040, PA 235, <2"
70 Oph* 4.1, 6.0 3.8" 148 88.1 K0V
Uranus and Neptune, dim at magnitudes 6 and 8, respectively, are in
Capricornus
Meteors - get up at 4 am and look east....
8 factors of 1000 in distance, 24 orders of magnitude!
48 orders of magnitude in brightness!!
30 m 30 x10^0 m 100 feet [something at "1st mag" and "12th mag"]
30 km 30 x10^3 m 20 miles Denver,
400 km 400x10^3 m 500 km International Space Station close pass
3 Mm 3 x10^6 m 3000 km Boston, is a candle about 11th mag?
42.2 Mm 42 x10^6 m 24 hr orbit Geosynchronous satellite orbit
384 Mm 384x10^6 m 384000 km Moon
56 Gm 56 x10^9 m 0.37 AU Mars - closest (Venus: .27 AU = 40 Gm)
150 Gm 150x10^9 m 1 AU Sun
1.4 Tm 1.4x10^12 m 9.5 AU Saturn
5.9 Tm 5.9x10^12 m 39.5 AU Pluto
10 Tm 30 x10^12 m Kuiper belt outer extents?
7 Pm 7 x10^15 m 50,000 AU Oort cloud
41 Pm 41 x10^15 m 4.40 ly Alpha Centauri - closest naked-eye star
222 Pm 222x10^15 m 25.3 ly Vega
13 Em 13 x10^18 m 1467 ly Deneb
600 Em 600x10^18 m 60 k ly M54 - far side of our galaxy
22 Zm 22 x10^21 m 2.4 M ly Andromeda galaxy, M31
110 Zm 110x10^21 m 12 M ly M64 Black-eye Spiral Galaxy
600 Zm 600x10^21 m 60-70 M ly M49, M87 in Virgo cluster, M77 in Cetus
25 Ym 25 x10^24 m 2 to 3 B ly 3C273, a quasar
170 Ym 170x10^24 m the edge of the visible universe
Andromeda - furthest photons with naked eye, 2.? M light years
With binoculors:
Look farther into the universe, as far as 60 to 70 million light years,
right into the heart of the Virgo cluster.
M87 in virgo, M49. Or cetus: M77
Easy Tough Challenge (for 7x35) 8: 10x80
may8C M58 Barred Spiral Galaxy Virgo 9.8 (8.2) 41000000 light-years
8T M77 Cetus
8T M87 Virgo 56 M ly major object in Virgo cluster, jet, many glob clusters
may C M51 Whirlpool Spiral Galaxy Canes Venatici 8.1 37000000 light-years
mar C M101 Spiral Galaxy Ursa Major 8.18 (9.6) 23000000 light-years
may T M94 Spiral Galaxy Canes Venatici 7.9 32600000 light-years
mar T M81 Spiral Galaxy Ursa Major 6.8 (7.9) 8500000 light-years
may T M64 Black-eye Spiral Galaxy Coma Berenices 9.34 (6.6) 11800000 light
nov T M33 Cartwheel Spiral Galaxy Tri 6.26 (6.7) (5.7) 2350000 light-years
T M49 Virgo Check it out! 60,000,000 ly
E M31 Andromeda
Easy Open: M6 M7 M11 M16 M18 M23 M24 M25 M29 M34 M35 M36 M37 M38 M39 M41
M44 M45 M46 M47 M48 M50 M52 M67 M93 M103
Easy Globular: M2 M3 M4 M5 M10 M12 M13 M15 M22 M53 M54 M55 M92
Easy Emission: M8 M17 M42 M
Easy Planetary: M27
Easy Galaxies: M31 Tougher: M49 M33 M64 M81 M94 Cool: M87
Reflection: M78 - harder
See info/messier
Easy: 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 22, 23,
24, 25, 27, 29, 31, 34, 35, 36, 37, 38, 39, 41, 42, 44, 45, 46, 47,
48, 50, 52, 55, 67, 92, 93, 103.
NGC 253 in Sculptor (easily visible in binoculars
at the 7th magnitude) and NGC 2403 in Camelopardalis (a more challenging 8th
magnitude galaxy)
Most distant object visible in a small telescope (200 mm, barely) :
Quasar 3C273 12h 29.2' +2 03', near Eta Virgo, the brightest quasar,
and first to be identified in 1963. Varies between 12-13 magnitude, 10^39 W.
2-3 billion light years. Observer's handbook p 275 Variable Galaxies.
== 187.2783 deg of RA, 2.05
Complex life on earth may be rare:
Carbonate-Silicate Cycle: need to recycle CO2 removed from atmosphere
by disolving in rain => need active crust and volcanic releases.
Also acts as slow-acting global thermostat: less CO2 loss when cold.
Too close to star: hydrogen (water) loss from water vapor at top of atmosphere
Cygnus X-1 - black hole orbiting red giant star, taking gas from
the star that is then is heated up near the black hole so it emits
x-rays before the gas is captured beyond the black hole event horizon.
http://astro.estec.esa.nl/SA-general/Projects/Hipparcos/apps/SelectArea.html
X-rays: imagine, body is transparent to x-rays, but atmosphere is not!
Hospital-like x-rays get no lower than about 40 km in atmosphere, and
even high-energy gamma rays don't penetrate much below 10 km
(Mt Everest). First observations (of solar corona with geiger
counter) by captured V2 missile in 1948. Now use satellites, like
recently-launched Chandra.
"X-ray source" is better (broader) than "X-ray star". While the
sun's corona does emit x-rays, the bright sources are clouds of hot
gas outside of stars at millions to hundreds of millions of degrees.
E.g. supernova remnants, neutron stars and black holes in a
double-star system, and stars with intensely hot atmospheres.
Further out: active galaxies and quasars powered by supermassive
black holes. Also clusters of galaxies embedded in enormous tenuous
pools of gas millions of light years across.
Location:
"Univ of Colo Observatory" from USGU topo map, 1980 Lon 105 31' Lat 39 57'
8720' altitude
At west end of Magnolia road, go 2 mi south of Nederland on peak-to-peak,
turn west on Magnolia ("no outlet") on short dirt road. Turn
left after about one mile - sign "14 day camping limit" on gate.
Free US Forest Service campground. Used by rainbow crowd.
40 min from Boulder.
2 mi north of South Boulder Creek and Rio Grande railroad line
http://www.mapblast.com/mblast/eLandmark.mb?CMD=LFILL&CT=39.945694:-105.520307:100000&MA=3&GAD3=CU%20Observatory,%20Magnolia%20Rd%2c+CO&Zip=80466&IC=39.945694:-105.520307:8:&loc=us&W=425&H=250
Or Walker Ranch picnic areas, but they are "closed at sunset" and less dark
Extra-solar planet info:
http://www.physics.sfsu.edu/~gmarcy/planetsearch/planetsearch.html
http://cfa-www.harvard.edu/planets/
http://wwwusr.obspm.fr/departement/darc/planets/everywhere.html
http://www.generation.net/~mariob/astro/xtrasol.htm
Star Name Msini (Mjup) Period (d) Semimajor Axis (AU) Ecc K (m/s)
1 HD 187123 0.52 3.097 0.042 0.00 72
2 Tau Bootis 3.64 3.3126 0.042 0.00 469
3 HD 75289 0.42 3.508 0.047 0.00 54
4 51 Pegasi 0.44 4.2308 0.051 0.01 56.
5 Upsilon Andromedae b 0.69 4.617 0.059 0.04 73.
6 Upsilon Andromedae c 2.0 241.3 0.82 0.23 54.
7 Upsilon Andromedae d 4.1 1280.6 2.4 0.31 67.
8 HD 217107 1.28 7.11 0.07 0.14 140
9 Rho1 55 Cancri 0.85 14.656 0.12 0.03 75.8
10 Gliese 86 3.6 15.8 0.11 0.04 379
11 HD 195019 3.43 18.3 0.14 0.05 268
12 Rho Corona Borealis 1.1 39.6 0.23 0.1 67.
13 HD 168443 5.04 58 0.28 0.54 330
14 Gliese 876 2.1 60.9 0.21 0.27 239.
15 HD114762 11.0 84 0.41 0.33 619
16 70 Virginis 7.4 116.7 0.47 0.40 316.8
17 HD 210277 1.36 437 1.15 0.45 41
18 16 Cygni B 1.74 802.8 1.70 0.68 52.2
19 47 Ursae Majoris 2.42 1093 2.08 0.10 47.2
20 14 Herculis 4 ~2000 ~3 ~0.35 80
star pc magV
51 Peg 14.7 5.5 RA = 22 57 27.14, DEC = +20 46 04.5
ups and 16.5 4.09 RA = 01 36 48.527, DEC = +41 24 38.71
rho crb 17 5.4 RA = 16 01 03.39, DEC = +33 18 51.5
16 cygB 21.4 6.20 RA = 19 41 51.8, DEC = +50 31 03
47 uma 13.3 5.10 RA = 10 59 29.296, DEC = +40 25 46.09
tau boo 15 4.50 RA = 13 47 17.345, DEC = +17 27 22.31
70 vir 22 5.0 RA = 13 28 26.541, DEC = +13 47 12.43
1999-07-30: Iota Horologii 56 light-years away, earth-like orbit,
sun-like star, twice-jupiter-sized planet.
novas: Try looking at http://www.aavso.org/
URANUS and NEPTUNE, dim at magnitudes 6 and 8, respectively, are in
Capricornus,
Pluto is in Ophiucus
References:
What can I see tonight (satellites, planets, constellations, etc)?
http://www.heavens-above.com/
General intro to astronomy by Mike Feltz with lots of links:
http://www.cyburban.com/~mrf/a_tableofconintro.html
Great information on constellations and stars:
http://www.astro.wisc.edu/~dolan/constellations/
Students for the Exploration and Development of Space
http://seds.lpl.arizona.edu/
Astronomical League Binocular Messier Certificate
http://www.astroleague.org/al/obsclubs/binomess/binomess.html
http://www.astroleague.org/al/obsclubs/binomess/binomesa.html
all 76 objects in Appendix A (Easy, Tough, and Challenge objects)
were observed with a pair of 7x35 Tasco binoculars purchased at
Wal-Mart for $19.00
Easy: 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 22, 23,
24, 25, 27, 29, 31, 34, 35, 36, 37, 38, 39, 41, 42, 44, 45, 46, 47,
48, 50, 52, 55, 67, 92, 93, 103.
Books: Burnham's Celestial Handbook, three volumes, revised edition 1978.
An engrossing collection of facts, stories, lore, data, pictures, etc.
distances:
LMC: 43-55 kpc
http://www.sciencemag.org/cgi/content/full/285/5434/1658
Designed to settle the issue of galactic distances, Hipparcos instead
"produced a lot of confusion,"
Parallax of nearby main sequence stars, then use them to get LMC
distance, then LMC calibrates cepheids for more distant galaxies,
then supernovas etc on to other galaxies
eclipsing binaries are the best hope for pinning down
the LMC distance once and for all,
Bypassing the Magellanic Cloud
http://www.sciencemag.org/cgi/content/full/285/5434/1661
Neal McBurnett
Last modified: Fri May 5 13:51:55 MDT 2000