An Evening's Tour of the Universe

	An Evening's Tour of the Universe.
	http://bcn.boulder.co.us/~neal/astro/tour.html
	  Neal McBurnett

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.

Given good weather there are always interesting things to see.
Constellations, planets, hopefully the Milky Way, earth satellites,
colorful double stars, asteroids, and more via the naked eye or
binoculars.  It's fun to find the newly-discovered solar systems, the
area where the Hubble Deep Field is, and other places in the news.

Summer Triangle: Deneb (Cygnus) Altair (Aquila) and Vega (Lyra)
  Sky is 3-D! Vega, 25.3 light-years away.  Deneb, not quite as bright,
  about 1,467 light-years distant.  3400 times brighter.  Would be mag
  -7.5 at 10 LY: Ten times brighter than Venus.  Mag -9.3 at distance
  of closest star.

Solar Apex near Vega: 19.4 km/s towards 18:07, +30

2.7 degree K cosmic microwave background radiation from the Big Bang

Most stars in the sky are double stars!
http://www.cyburban.com/~mrf/a_doublestars.htm
  Double stars in Lyra in a small triangle with Vega:
    Epsilon Lyr - the "double double": 208" between the two double stars.
	E1 (north) are 2.8" apart, E2 are 2.6" apart and you need
	a telescope with 100x magnification to see them.  They have
	orbits of perhaps hundreds to thousands of years, and the
	orbit of the two pairs (0.2 ly apart) is perhaps a million years.
    Zeta Lyr: 44" apart, 3-1 brightness difference.
    Delta 1&2 Lyra - naked eye/binocular pair, huge color separation
  Beautiful Albireo, Beta Cygni, 34" separation, 3.4 and 5.1 mag, red/blue
  Gamma and 11 Ursa Minor (far end of little dipper) great naked eye contrast

mu Cepheus, (below house shape) very red, perhaps biggest visible
	(size of saturn's orbit)

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 

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)
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

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.

  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, 2.9 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.

Also NGC 253 in Sculptor.

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

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

Iridium flares and other satellites, e.g. rapidly tumbling SL-16:
 from http://www2.gsoc.dlr.de/scripts/satvis/satvis.asp?Lat=40.0017&Lng=-105.2431&Loc=Boulder&TZ=MST

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


Neal McBurnett
Last modified: Fri Mar 26 14:42:56 MST 2004