We often dream of traveling 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, and deeply related to our existance. We are star-stuff: the Big Bang and and supernovae created the elements that our bodies are made of.
This week we'll see Mars, the Moon, constellations, stars, planets, Earth satellites, and more via the naked eye, binoculars and a small telescope. There is a chance that we will still be able to glimpse Comet Linear C/2001. For your mind's eye we'll point out newly-discovered solar systems, black holes, X-ray sources, the Hubble Deep Field and bask (as always :-) in the presence of the 2.73 degree K cosmic microwave background radiation from the Big Bang.
Carbondale is located at 39.40° N latitude, 107.21° W longitude. This week sunset (on a flat horizon) is about 8:30, and twilight ends between 9:30-10:15. Sunrise is about 6:06. The sun is in the constellation Cancer, even though traditional astrology calls people born now
We'll be able to see lots of satellites go overhead, including the International Space Station. Thanks to http://www.heavens-above.com/ for this data, and tons of other good information:
| Date | Mag | Starts | Max. Altitude | Ends | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Time | Alt. | Az. | Time | Alt. | Az. | Time | Alt. | Az. | ||
| 30 Jul | -0.7 | 22:16:13 | 10 | SW | 22:19:23 | 88 | S | 22:19:32 | 82 | ENE |
| 31 Jul | -0.1 | 21:20:50 | 10 | SSW | 21:23:50 | 38 | SE | 21:26:51 | 10 | ENE |
| 01 Aug | 0.6 | 22:01:15 | 10 | WSW | 22:04:19 | 43 | NNW | 22:07:26 | 10 | NE |
| 02 Aug | -0.6 | 21:05:24 | 10 | SW | 21:08:37 | 87 | E | 21:11:48 | 10 | NE |
And some Iridium flares (15 seconds of bright mirror-like reflections off big antennas of the Iridium satellites):
| Date | Local Time | Intensity ( Mag) | Alt. | Azimuth | Distance to flare centre | Intensity at flare centre (Mag.) | Satellite | 29 Jul | 23:03:45 | -6 | 12° | 261° (W ) | 35.4 km (E) | -6 | Iridium 86 |
|---|---|---|---|---|---|---|---|
| 01 Aug | 23:17:55 | -1 | 10° | 38° (NE ) | 56.2 km (W) | -6 | Iridium 66 |
| 02 Aug | 23:12:01 | -6 | 11° | 40° (NE ) | 13.9 km (E) | -6 | Iridium 74 |
And even one visible during the day!
| Date | Local Time | Intensity (Mag.) | Flare position | Flare centre | Sun | Satellite | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Alt. | Azimuth | Distance | Mag | Alt. | Azimuth | From flare | ||||
| 01 Aug | 08:37:35 | -6.1 | 42° | 100° (E ) | 0.1 km (W) | -6.1 | 27° | 88° (E ) | 18° | Iridium 16 |
Mars is nearby and visible most of the night: bright and orange and to the south. Venus is very bright in the morning sky.
Constellations - find the Big Dipper ("Ursa Major"), the North Star, the Summer Triangle, Lyra, Cygnus, Leo, Bootes, Sagittarius, Scorpius, Cassiopea.
Remember - the sky is three-dimentional - some stuff is really close, and other stuff is VERY far away. The Summer Triangle is the three stars Deneb (Cygnus) Altair (Aquila) and Vega (Lyra). Vega is only 25.3 light-years away. Deneb, not quite as bright, is perhaps 1500 light-years distant, which makes it 3400 times brighter! If it were as close as the nearest star, it would be magnitude -9.3, probably as bright as the crescent moon.
The 2.73 K (= -454° Fahrenheit) cosmic microwave background radiation from the Big Bang comes from all directions and is incredibly uniform. But observations of tiny fluctuations are now demonstrating that the universe is "flat" (light moves in parallel lines) and is going to expand forever.
Relative to other stars, on average, the sun is moving towards Vega at 19.4 km/s. But relative to the galaxies, it is moving towards a spot in Hydra, below Leo, at 369 km/s!
The Milky Way is visible to the south in Sagittarius, but light pollution is a big problem even here in the mountains. Please don't let lights shine skyward, and join the International Dark-Sky Association (IDA) http://www.darksky.org/
The "Hubble Deep Field" is a spot that the Hubble Space Telescope looked at for a total of 10 days. It is above handle of the Big Dipper. See the poster on the wall inside, and then reflect on the fact that it is only the width of a dime at 75 feet: (5 square arc-minutes). That is one 30-millionth of the sky. It isn't unusual, but it contains 1317 cataloged galaxies!!
We now know of dozens of nearby stars with planets. Tau Bootis is middle of three in bottom right of Bootes (there is an arrow to it on the Sky Chart). It goes around the star every 3.3 days, and is perhaps 3.6 times heavier than Jupiter. The star is 49 ly away, and is similar to the sun.
For your best shot at meteors - get up at 4 am and look east :-)
X-rays: imagine, our body is pretty transparent to x-rays, but the atmosphere is not! Cygnus X-1 is a black hole orbiting a 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.