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February Skies

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February Skies

by Dick Cookman


Highlights: Comet Journal, Martian Landers, Meteor Showers, Starlight - Starbright, Planet Plotting, February Moon

Focus Constellations: Camelopardalis, Cassiopeia, Cepheus, Draco, Ursa Minor, Ursa Major, Lynx, Gemini, Orion, Taurus, Auriga, Perseus

Comet Journal

Comet C/2011 L4 (PanSTARRS) increased brightness as expected in December but then slowed the rate of increase in January. At the end of December the comet was projected to reach 1st magnitude when it appears in northern skies in early March but that projection has now been reduced to 3rd magnitude. It is currently about 7th magnitude and is moving northeastward through southern skies at about declination -40°. It will move from Corona Australis to Pisces in February.

Comet C/2012 S1 (ISON) is nearing 14th magnitude well ahead of projections as it circles through northern Gemini! The comet passed the orbit of Jupiter in January and is now approaching the Asteroid Belt. Comet Ison's orbit has been determined as nearly parabolic indicating that the point of origin was probably in the Oort Belt about one light year from the Sun. If it lives up to expectations when it passes through the inner Solar System at the end of 2013, it may be one of the brightest comets observed since 1935.

In late November the comet will be at its brightest before and after perihelion on November 28th when it plunges through the corona of the Sun. It will remain very bright when passing closest to Earth on December 26th as it moves away from the Sun.

C/2012 F6 (Lemmon) provided a fortuitous surprise to observers in October of 2012 when it appeared 2 to 3 magnitudes brighter than expected. Projections that it would peak at 9th magnitude have been upgraded to 3rd magnitude when it is near perihelion on March 24th, one year after its discovery by A. R. Gibbs at the Mr. Lemmon Observatory. It is currently at magnitude 6.9 near the south celestial pole and will become visible in the northern hemisphere in May.

Comet C/2012 K5 ( LINEAR ) peaked at 7th magnitude when it descended through our orbital plane about 0.3 Astronomical Units beyond Earth in early January. Its orbit is perpendicular to that of Earth and it orbited out of the northern hemisphere sky and into that of the southern hemisphere. It has since dropped to 10th magnitude and will decrease to 12th magnitude as it moves through Eridanus and Lepus.

Martian Landers

Curiosity is currently in a depression called Yellow Knife Bay. In late December the rover briefly examined 2 rock targets called °Costello° and °Flaherty° with the Alpha Particle X-Ray Spectrometer (APXS) and Mars Hand Lens Imager (MAHLI) at the end of the rover°s arm and then proceeded with detailed imaging of the depression. Yellow Knife Bay contains sandstones of a lighter color than the pebbly conglomerate previously encountered in the dry streambed where Curiosity landed and the rock of the intervening terrain. The sandstones are one of three types of rock that intersect at a location dubbed Glenelg, chosen as an interim destination about two weeks after the landing. On Jan. 3rd the rover approached and imaged a sinuous ridge of darker rock dubbed Snake River which appears to cut through the surrounding light colored relatively horizontal layers.

By the 15th, mission scientists selected an area of light colored sandstone with included veins, nodules, cross-bedded layering, and a lustrous embedded pebble as a target for initial drilling. The veins are most likely composed of gypsum deposited by calcium, sulfur and hydrogen bearing water circulating through fractured rock layers. Preparations for this drilling are expected to be completed by mid-February.

From Sol 3165 (Dec. 18, 2012) through 3206 (Jan. 29, 2013), Opportunity examined rocks in the Copper Cliff, Whitewater Lake and Flack Lake exposures. A small dust cleaning event occurred on Dec. 29th enabling Solar array energy production to be maintained close to 534 watt-hours per day during the interval.

Meteor Showers

The Alpha Centurid meteors are the only significant meteor shower in February. They occur on the 8th but are limited to southern hemisphere skies.

February skies are occasionally visited by Fireballs which are defined as meteors brighter than Venus. Although the fireballs occur no more frequently than in other months, February seems to have more frequent bright fireballs. The light produced by meteors is not limited to the glowing sand size particle but is also produced by the particles slamming through the air and heating it to incandescence. Fireballs are likely to result from relatively slow moving boulder size meteoroids ranging from one to thirty feet in diameter which may last as long as 5 to 10 seconds. When fireballs shoot through the sky behind them, people turn around to look because they see the brilliant light reflected from trees and other objects in front of them.

Starlight - Starbright

February evening skies are replete with bright first magnitude stars. They include the following in order of brightness: Sirius (-1.46) in Canis Major, Rigel (+0.1) in Orion, Capella (+0.1) in Auriga, Procyon (+0.4) in Canis Minor, Betelguese (+0.5) in Orion, Aldebaran (+0.9) in Taurus, Regulus (+1.4) in Leo, Pollux (+1.6) in Gemini.

The quadrant of the sky displaying the intersection of the planes of the Solar System and the Milky Way Galaxy is above our location in February providing a view of the closest part of the dense Orion Spiral Arm of our galaxy which has abundant interstellar gas & dust clouds from which bright giant young stars can form. Nights may be cold but they sure are spectacular!

Planet Plotting

The early evening planets of February include Neptune, Mercury and Mars low in the west and Uranus slightly higher when Jupiter is high in the south. Saturn rises slightly before midnight as Jupiter sets and reigns alone until Venus rises slightly before the Sun. Neptune (+8.0), Mercury (-1.1 to +3.1) and Mars (+1.2) spend most of the month in Aquarius while Uranus (+5.9) is in Pisces, Jupiter (-2.5 to -2.3) in Taurus, Saturn (+0.5 to +0.4) in Libra, and Venus (-3.9) follows the Sun through Capricornus and Aquarius.

Mercury, Mars, and Neptune engage in numerous conjunctions on the 4th, 6th, 8th, 25th, and 28th. Conjunctionitis is a condition producing red, itchy eyes in planetary aficionados who spend inordinate amounts of time peering through their telescopes in an attempt to observe every planetary conjunction. As can be seen in the table below, the numerous conjunctions this month indicate that the condition is likely to be quite prevalent.

Planet Constellation Magnitude Planet Passages
Sun Capricornus, Aquarius -26.8  
Mercury Capricornus, Aquarius, Pisces -1.1/-0.3/+3.1 Neptune 0.41°NNW, 2/6, 7PM EST
Mars 0.27°SSE, 2/8, 1PM EST
Max. East Elongation, 2/16, 4PM EST
Perihelion, 2/17, 9PM EST
Mars 4.1°SSE, 2/25, 5PM EST
Venus Capricornus, Aquarius -3.9 Neptune 0.72°NNW, 2/28, 9AM EST
Mars Aquarius +1.2 Neptune 0.41°NNW, 2/4, 5PM EST
Mercury 0.27°NNW, 2/8, 1PM EST
Mercury 4.1°NNW, 2/25, 5PM EST
Jupiter Taurus -2.5 to -2.3  
Saturn Libra +0.5 to +0.4  
Uranus Pisces +5.9  
Neptune Aquarius +8.0 Mars 0.41°SSE, 2/4, 5PM EST
Mercury 0.41°SSE, 2/6, 7PM EST
Solar Conjunction, 2/21, 2AM EST
Venus 0.72°SSE, 2/28, 9AM EST

February Moon

The New Moon at 2:44 PM EST on Jan. 11th marked the beginning of Lunation 1114 which ends with New Moon at 2:44 PM EST on Feb. 10th. This lunation is 29.48 days long.

February's Full Moon is on the 25th at 3:26PM EST and is referred to as the "Wolf," "Snow," or "Hunger Moon." Colonial Americans called it the "Trapper's Moon" and the Celts referred to it as the "Moon of Ice." Chinese call it the "Budding" Moon and medieval English named it the "Storm Moon." To northern Michigan Anishnaabe (Chippewa and Ojibwe) it is "Namebini-giizis" (Sucker Moon).

On the 5th at 7:14AM EST the Moon will be at perigee, its closest approach to Earth during February. It will be 226,998 miles or 57.28 Earth radii. Apogee occurs on the 19th at 1:29AM EST when it will be at 63.42 Earth Radii or 251,327 miles from Earth.

Planet Constellation Magnitude Moon Passage & Phase/Age
Sun Capricornus -26.8 2:20 AM EST 2/10 New ~ 0 days
Mercury Aquarius -0.4 5.0°N, 1PM EST, 2/11 Waxing Crescent ~ 1.44 days
Venus Capricornus -3.9 5.8°NNW, 5AM EST, 2/9 Waning Crescent ~ 28.59 days
Mars Aquarius +1.2 5.8°NNW 5AM EST, 2/11 Waxing Crescent ~ 1.11 days
Jupiter Taurus -2.4 0.9°S, 7AM EST, 2/18 Waxing Gibbous ~ 8.19 days
Saturn Libra +0.5 3.0°S, 5AM EST, 2/3 Waning Gibbous ~ 22.59 days
Uranus Pisces +5.9 4.0°N,11AM EST, 2/13 Waxing Crescent ~ 3.36 days
Neptune Aquarius +8.0 5.5°NNW, 8PM EST, 2/10 Waxing Crescent ~ 0.74 days


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