TSTW 2/4/10 (for Dodgeville, Wisconsin)
Thursday, February 4
The Iridium 40 satellite will flare to -1 magnitude around 7:22 p.m. at azimuth 22° (NNE) and altitude 37°, in Ursa Major, about a third of the way between the Pointer Stars and Polaris.
Mars is closest to the Beehive Cluster (M44) tonight. Use binoculars.
Algol ( Persei) is at minimum brightness, 11:56 p.m.
Friday, February 5
Last Quarter Moon; rises 12:27 a.m. transits 5:23 a.m.; sets 10:11 a.m.; = -22°
Sunday, February 7
Antares is near the Moon this morning before dawn.
ISS 5:41 a.m. SW - 5:42 a.m. SE (83°) - 5:45 a.m. ENE; leaves the shadow of the Earth above Saturn, passes through Boötes and Cygnus; astronomical twilight.
Algol is at minimum brightness, 8:45 p.m.
Monday, February 8
Space Shuttle Endeavour is scheduled to launch from the Kennedy Space Center at 3:14 a.m. on a mission to the International Space Station.
The Moon rises at its most southerly point along the eastern horizon this month at 3:37 a.m.
Tuesday, February 9
Peggy Whitson (1960-), American astronaut, was born in Mount Ayr, Iowa, 50 years ago.
Wednesday, February 10
The 16.2-magnitude asteroid 493 Griseldis may pass in front of the 8.9-magnitude star HD 115354 in Virgo for up to 8.9 seconds around 2:05 a.m. For more info, visit http://asteroidoccultation.com/asteroid.htm.
Solar Dynamics Observatory (SDO) is scheduled to launch between 9:26 and 10:26 a.m. from Cape Canaveral.
UARS (Upper Atmosphere Research Satellite, deployed from Space Shuttle Discovery in 1991) will move from SW to SSW from about 7:14 to 7:17 p.m. It reaches its highest point in the sky (60° altitude, magnitude 2.6) around 7:17 p.m., in Taurus, where it disappears into the shadow of the Earth.
The reddest red your eyes can see has a wavelength around 750 nm. A stellar photosphere with a temperature of 6500° F would shine the brightest at this wavelength. Cooler stars (and cooler circumstellar and interstellar dust) would radiate brightest in the infrared region of the electromagnetic spectrum.
The Earth's atmosphere is opaque (or nearly so) across much of the infrared spectrum, but there are "windows" where the atmosphere is partially transparent. The four best windows in the near infrared are the J, H, K, and L bands.
The J band ranges from 1050 to 1340 nm. Objects having a temperature of 4510° F down to 2160° F would radiate most brightly in the J band.
The H band ranges from 1550 to 1750 nm. Objects having a temperature of 1870° F down to 1660° F would radiate most brightly in the H band.
The K band ranges from 2000 to 2400 nm. Objects having a temperature of 1450° F down to 1210° F would radiate most brightly in the K band.
The L band ranges from 3300 to 4200 nm. Objects having a temperature of 880° F down to 690° F would radiate most brightly in the L band. The L band is the clearest window we have into the infrared from ground based observatories.
Incidentally, the I band of UBVRI fame ranges from 725 to 875 nm. It ranges from the red end of the visible spectrum to just slightly into the infrared. It is much closer to the visible spectrum than to the J band of the infrared.
Our eyes see only a tiny portion of the electromagnetic spectrum. Up until the 20th century, everything we could observe about the universe came from visible light. Now, astronomers regularly observe the universe at wavelengths of light our eyes cannot see. This includes radio waves, microwaves, infrared radiation, ultraviolet light, x-rays, and gamma rays.
Each time we open up a new frontier in the electromagnetic spectrum, we discover many new and wonderful things about our universe.
But why limit ourselves to "only" the electromagnetic spectrum? We now have neutrino telescopes that can detect these elusive, nearly massless subatomic particles produced deep in the interiors of stars and through other high-energy astrophysical processes.
A new realm of exploration, sure to uncover many strange and exotic phenomena, is gravitational waves. Predicted by Albert Einstein in 1916, gravitational waves have never been directly detected. But that will change soon.
What are gravitational waves? They are ripples in space-time caused by the acceleration of massive objects. Certain types of events, such as two black holes closely orbiting each other and spiraling in towards eventual collision, would be sure to generate some very strong gravitational waves.
But these waves are extremely difficult to detect. An effective detector needs to be able to measure changes in length (as a gravitational wave passes) that are less than a thousandth of the diameter of a proton.
Such small fluctuations in space-time should be detectable soon by the Laser Interferometer Gravitational Wave Observatory (LIGO), currently operating near Livingston, Louisiana and Richland, Washington. For more information about this exciting project, visit www.ligo.org.
On January 6, a Lincoln Near Earth Asteroid Research (LINEAR) telescope at White Sands Missile Range near Socorro, New Mexico imaged a 19th-magnitude object that at first looked like a comet, and it was given the cometary designation P/2010 A2. However, it is rare for a comet in that it orbits within the asteroid belt and has a very un-cometlike orbital eccentricity of 0.124. Also, there is no evidence for a nucleus within the coma, the tail is all dust and no gas, and the structure of the whole thing is unusual to say the least! It is now thought to be the result of the collision between two asteroids. Although a frequent occurrence over millions of years, the opportunity to witness such a collision in our lifetime is extremely fortuitous indeed!
