TSTW 1/12/12
Thursday, January 12
Ercole Dembowski (1812-1881), Italian astronomer who was a prolific observer of double stars, was born 200 years ago.
CZ-3 rocket body (SW to S) - 7:21:00 p.m. near Fomalhaut; 7:21:51 disappears into the shadow of the Earth in Fornax; 0.0m, 24°; astronomical twilight
The Iridium 55 satellite will sunglint to -2 magnitude around 7:43:26 p.m. at azimuth 38° (NE) and altitude 50°, to the left of the pentagon of Auriga.
The 17.9-magnitude unnamed asteroid 19927 (1980 FM4) may pass in front of the 8.0-magnitude star HD 60521 in Gemini for up to 0.5 seconds around 9:11:12 p.m.
Europa disappears into Jupiter's shadow around 9:42 p.m.
Io reappears from Jupiter's shadow around 11:26 p.m.
Friday, January 13
Europa reappears from Jupiter's shadow around 12:09 a.m.
The Moon crosses the celestial equator heading south.
CZ-3 rocket body (SW to SE) - 7:14:08 p.m. near Fomalhaut; 7:15:17 disappears into the shadow of the Earth in Eridanus; -0.0m, 24°; astronomical twilight
The Iridium 31 satellite will sunglint to -2 magnitude around 7:37:21 p.m. at azimuth 41° (NE) and altitude 49°, to the left of the pentagon of Auriga as astronomical twilight ends.
The Great Red Spot crosses Jupiter's central meridian around 8:35 p.m.
Saturday, January 14
Mars is near the Moon this morning before dawn.
The 16.3-magnitude asteroid 4516 Pugovkin may pass in front of the 9.3-magnitude star HD 45193 in Gemini for up to 1.0 seconds around 3:49:19 a.m.
Latest Onset of Morning Twilight (standard time), 6:27:51 a.m.
Ganymede reappears from Jupiter's shadow around 7:50 p.m.
The 15.7-magnitude unnamed asteroid 5925 (1994 CP1) may pass in front of the 10.0-magnitude star Tycho 1935-00701-1 in Cancer for up to 0.8 seconds around 10:10:44 p.m.
Sunday, January 15
The Phobos-Grunt spacecraft, which was launched November 8 for a mission to Mars but failed to leave Earth orbit, is expected to re-enter the Earth's atmosphere today between 7:26 a.m. and 5:02 p.m., with the most likely time being around 12:14 p.m..
The Great Red Spot crosses Jupiter's central meridian around 10:14 p.m.
Sirius, the brightest star in the night sky, transits the celestial meridian at midnight tonight.
Monday, January 16
Last Quarter Moon, 3:08 a.m.; rises 1:11 a.m.; transits 6:51 a.m.; sets 12:25 p.m.; δ = -14°
Spica and Saturn are near the Moon this morning before dawn.
Tuesday, January 17
Harvey Nininger (1887-1986), American meteoriticist who essentially established the field, was born 125 years ago.
The Great Red Spot crosses Jupiter's central meridian around 11:53 p.m.
Wednesday, January 18
The Great Red Spot crosses Jupiter's central meridian around 7:45 p.m.
January Antihelion meteors may be seen around this date (3 meteors per hour, or less). The antihelion radiant is currently located in Cancer.
Thursday, January 19
Antares is near the Moon this morning before dawn. They are closest at 5:26 a.m.
Saturn is at west quadrature (90° west of the Sun) and thus exhibits its most gibbous phase (99.7% illuminated).
• Galileo didn't see the Orion Nebula. [Steven J. Dick]
• Giuseppe Piazzi discovered a new "planet", Ceres, on 1801 Jan 1. After Heinrich Olbers discovered Pallas on 1802 Mar 28, William Herschel wrote Piazzi on 1802 May 22, admonishing him to not call these objects "planets" in the traditional sense, but "asteroids" (Greek: "star-like") instead. Herschel invented this term. [Steven J. Dick]
• Peer-review of astronomy journal articles (rather than just editorial review) is a relatively recent phenomenon—generally beginning in the 1950s. [Joseph S. Tenn]
• Hans Bethe (1906-2005) had a scientific publishing career lasting 80 years—longer than any other astrophysicist or astronomer in history. [Joseph S. Tenn]
• An interesting exercise: looking at the span of time a particular journal article is cited in later work (http://ads.harvard.edu). [Joseph S. Tenn]
• Syzygy: a straight line configuration of three celestial bodies in a gravitational system. Perigean spring tides occur when the Moon is at perigee and the Earth is at perihelion. An extreme perigean spring tide occurred 100 years ago this month, on 1912 Jan 4. Earth reached perihelion on 1912 Jan 3 at 10:44 UT, full moon occurred 1912 Jan 4 at 13:29 UT, and lunar perigee—the closest in over 1,400 years—occurred just 6 minutes later on 1912 Jan 4 13:35 UT. [Donald W. Olson]
• Three independent pre-telescopic star catalogs gave star positions and magnitudes: Ptolemy's Almagest (c.150), al Sufi's Book of Fixed Stars (964), and Tycho Brahe's Thousand Star Catalog (1598). Remarkably, all three of these star catalogs list magnitudes that have been corrected for atmospheric extinction, and yet the earliest reference to extinction in the literature may have been in 1729. [Bradley E. Schaefer]
• In archaeoastronomy, many so called astronomical alignments are just random and have no historical significance. A lack of standards is limiting the ability for archaeoastronomy to be accepted by the wider scientific community. Some of the most published sites in the southwest U.S. are bogus from an archaeoastronomy point of view. [Anthony B. Hull, Use of Monte Carlo Methods for Evaluating Probability of False Positives in Archaeoastronomy Alignments]
• Kennicutt-Schmidt Law: a relation between the gas density and star-formation rate in a given region. [Robert A. Benjamin]
• Longitude-Velocity diagrams (l-v diagrams): gas radial velocity vs. galactic longitude graph is useful. Beyond the solar circle, we can associate each position given by galactic longitude and distance with a point on the l-v diagram. However, the inverse is not generally true: any line-of-sight towards the galactic interior present us with two distances whose emission appears at the same radial velocity. [Robert A. Benjamin]
• 21 cm emission of neutral hydrogen (spin-flip transition) and carbon monoxide (CO) emission help us trace the gas distribution and motions in our galaxy. Molecular hydrogen does not emit detectable radio energy, but it is co-located with CO, so the easily detected CO emission lines (2.6 and 1.3 mm) are used to trace the H2. [Robert A. Benjamin]
• VLBI maser parallaxes are useful for determining distances throughout our galaxy. [Robert A. Benjamin]
• The inner 500 parsecs of our Milky Way galaxy is a very different environment from the rest of the galaxy. [Robert A. Benjamin]
• Red clump giants (RC giants) are excellent standard candles. There are many nearby, and they are very numerous. [Robert A. Benjamin]
• A longitude-magnitude diagram helps us to identify large scale stellar structures in the Milky Way galaxy
• The molecular gas in the outer Scutum-Centaurus spiral arm is the most distant yet detected in our Milky Way galaxy: 21 kpc from the galactic center. [Robert A. Benjamin]
• Ethanol (C2H5OH) maser emission has proven to be an excellent tracer of regions undergoing massive star formation. [Robert A. Benjamin]
To be continued next week...
