October 1999 Events

All times in 24 hour format (EDT = Eastern Daylight Time, EST = Easter Standard Time, UT = Universal Time) Subtract 1 hour for Central Time, 2 hours for Mountain Time, and 3 hours for Pacific Time. Add 4 hours to EDT for Universal Time. Add 5 hours to EST for Universal Time.

MOON PHASES

• New Moon - Oct. 9, 7:34 a.m. EDT (11:34 UT)
• First Quarter - Oct. 17, 11:00 a.m. EDT (15:00 UT)
• *Full Moon - Oct. 24, 5:02 p.m. EDT (21:02 UT)
• Last Quarter - Oct. 31, 7:04 a.m. EST (12:04 UT)

* Hunter's Moon - Oct. 24, the second full moon after the autumnal equinox (Sept. 23). The first full moon is called the Harvest Moon. The Hunter's Moon begins a second period of days when the moon rises soon after sunset, giving temperate climates more light in the evening, though not for as long as the evenings following the Harvest Moon. This time would allow the farmers, finished with their harvesting, to hunt for game which they would add to their provisions for the winter.

MOON'S APOGEE AND PERIGEE

• apogee: 251,814 miles, Oct. 14, 9:50 a.m. EDT (13:50 UT)
• perigee: 224, 284 miles, Oct. 26, 8:58 a.m. EDT (12:58 UT)

MORNING AND EVENING PLANETS

• Morning - Venus, Jupiter (through Oct. 22), Saturn
• Evening - Mercury, Mars, Jupiter (from Oct. 23), Uranus, Neptune, Pluto

SUN, MOON AND PLANETS
SUN - (dist.: 92.9 mill. mi.) begins the month in the constellation Virgo, is in conjunction with minor planet Vesta on the 21st, and enters the constellation Libra on the 31st.
MOON - passes Venus and the star Regulus on the 5th, Mercury on the 10th, Mars on the 15th, Neptune on the 18th, Uranus on the 19th, Jupiter on the 24th, Saturn on the 25th, and the star Aldebaran on the 27th.
MERCURY - (mag. -0.3 to 0.1, dist.: 123.3 to 83.2 mill. mi., color: yellow) is very low in the southwest in the early evening sky. It begins the month in the constellation Virgo, is passed by the moon on the 10th, enters the constellation Libra on the 11th, and reaches greatest eastern elongation (24°) on the 24th.
VENUS - (mag. -4.5 to -4.4, dist.: 43.6 to 64.2 mill. mi., color: yellow) is low in the eastern sky before dawn. It spends the month in the constellation Leo. It is passed by the moon on the 5th, passes the star Regulus on the 8th, and reaches greatest western elongation (46°) on the 30th.
MARS - (mag. 0.6, dist.: 132.9 mill. mi., color: orange) is getting lower in the west-southwestern sky in the evening. It begins the month in the constellation Ophiucus, is very near the 3.3-magnitude star Theta Ophiuchi on the 4th, enters the constellation Sagittarius on the 11th, is passed by the moon on the 15th, is 0.8° south of the Lagoon Nebula (M8) on the 17th, is 0.3° south of the 8th-magnitude globular cluster NGC 6544 on the 18th, is 0.5° south of globular cluster M28 on the 23rd, and is 1° south of globular cluster M22 on the 27th.
JUPITER - (mag. -2.9, dist.: 369.0 mill. mi., color: yellow-tan) is visible in the sky all night. It begins the month in the constellation Aries. It enters the constellation Pisces on the 13th, is at opposition on the 23rd, and is passed by the moon on the 24th.
SATURN - (mag. -0.1 dist.: 769.5 mill. mi., color: yellow) is visible in the sky all night, following Jupiter as it approaches opposition in November. It spends the month in the constellation Aries. It is passed by the moon on the 25th.
URANUS - (mag. 5.8, dist.: 1,814.0 mill. mi., color: greenish) is within the constellation Capricornus, less than 1 degree from the 4.1-magnitude star Theta Capricorni. It is passed by the moon on the 19th, and is stationary on the 23rd.
NEPTUNE - (mag. 7.9, dist.: 2,780.2 mill. mi., color: bluish) is also within the constellation Capricornus, roughly 1 degree west and slightly south of the 5.3-magnitude star Sigma Capricorni. It is stationary, resuming direct motion on the 13th, and is passed by the moon on the 18th.
PLUTO - (mag. 13.8, dist.: 2,866.3 mill. mi., color: reddish) spends the month in the constellation Ophiucus. It is less than 0.5° from minor planet Juno on the 5th.

EVENTS
Oct. 4 - Mars is very near the 3.3-magnitude star Theta Ophiuchi in the constellation Ophiucus
Oct. 5 - The moon is 5° north of Venus, 1 p.m. EDT; The moon is 1.2° north of the star Regulus in the constellation Leo (occulting Regulus as seen from some locations), 6 p.m. EDT; Pluto (magnitude 13.8) is less than 0.5° from minor planet Juno as it passes through the constellation Ophiuchus.
Oct. 8 - Venus is 3° south of the star Regulus in the constellation Leo, 6 p.m. EDT
Oct. 10 - The moon is 7° north of Mercury, 11 p.m. EDT
Oct. 11 - Mars enters the constellation Sagittarius; Mercury enters the constellation Libra
Oct. 13 - Jupiter enters the constellation Pisces; Neptune is stationary, resuming direct motion, 6 p.m. EDT
Oct. 15 - The moon is 5° north of Mars, 9 a.m. EDT
Oct. 17 - Mars is 0.8° south of the Lagoon Nebula (M8)
Oct. 18 - The moon is 0.5° north of Neptune (occulting Neptune as seen from some locations), 3 a.m. EDT; Mars is 0.3° south of the 8th-magnitude globular cluster NGC 6544
Oct. 19 - The moon is 0.4° north of Uranus (occulting Uranus from as seen from North America), 1 a.m. EDT
Oct. 21 - Minor planet Vesta is in conjunction with the Sun, 11 p.m. EDT
Oct. 22 - Peak of the Orionid meteor shower
Oct. 23 - Uranus is stationary, 7 a.m. EDT; Jupiter is at opposition, 3 p.m. EDT; Mars is 0.5° south of globular cluster M28
Oct. 24 - The moon is 4° south of Jupiter, 1 p.m. EDT; Mercury is at greatest eastern elongation (24°), 6 p.m. EDT
Oct. 25 - The moon is 2° south of Saturn, 2 p.m. EDT
Oct. 27 - The moon is 1.2° north of the star Aldebaran in the constellation Taurus (occulting Aldebaran as seen from some locations), 8 a.m. EDT; Mars is 1° south of globular cluster M22
Oct. 30 - Venus is at greatest western elongation (46°), 8 p.m. EDT
Oct. 31 - At 2 a.m. Daylight Savings Time ends. Set your clocks back one hour (2 a.m. EDT becomes 1 a.m. EST, Eastern Standard Time). The Sun enters the constellation Libra.

COMET LEE (designated C/1999 H1 Lee)
The comet was discovered April 16, 1999 by night assistant Steven Lee of the Anglo-Australian Observatory. Comet Lee rounded the Sun on July 11 and moved into the morning sky. It was an object visible with binoculars for most of August and September. Now, however, it can be best seen with a telescope. During October the comet is high overhead around midnight.

On October 3, Comet Lee shines at magnitude 8.9 as it passes about 8° north of the Andromeda Galaxy (M31) and 1° north of NGC 147, one of M31's dim satellite galaxies, in the constellation Cassiopeia. On October 18 and 19, Comet Lee passes 0.7° west of the star Scheat (Beta Pegasi) in the constellation Pegasus. By this time the comet will have dimmed another magnitude. However, the nearby star Scheat will provide a useful guide to its position. Comet Lee will spend the rest of the month within Pegasus. Viewing will become difficult as the moon climbs higher each night until it becomes full on October 24 (the Hunter's Moon).

JUPITER AT OPPOSITION
Jupiter reaches opposition on October 23. Opposition means that Jupiter is opposite in the sky from the Sun when viewed from Earth. Jupiter rises as the Sun sets, and appears highest in the sky around midnight. This is the closest and brightest Jupiter will appear for the year. This year's opposition is more spectacular because Jupiter was just recently at perihelion, its closest point to the Sun during its 12-year orbit. This puts Jupiter 368 million miles from Earth. For this reason Jupiter will not appear this large (nearly 50" across) and this bright (mag -2.9) for about 12 years.

In a good pair of binoculars you can seen the disk of Jupiter and its four largest moons, which appear as stars as they orbit the planet. These moons are Ganymede, Europa, Callisto, and Io. These are called the Galilean satellites because they were first observed by Italian astronomer Galileo Galilei in 1610. Galileo used them as proof that not everything in the universe revolved around the Earth. By observing Jupiter over several hours, or just watching briefly night by night, you will see the moons change position. Binoculars of larger aperture and small telescopes (3" aperture) may begin to make out the more prominent cloud bands of Jupiter. A bluish or greenish eyepiece filter will help the reddish-brown coloring of Jupiter stand out better. Jupiter rotates in 9.8 hours and larger telescopes will begin to perceive the smaller cloud bands as the move across the disk. You may also see the Great Red Spot, the long-lasting storm in Jupiter's southern hemisphere.

SATURN APPROACHING OPPOSITION
Saturn will reach opposition early in November and can be seen this month about 15° east of Jupiter. Saturn's rings are very prominent and can be seen in good detail through telescopes of 4" aperture and larger. A good pair of binoculars will show Saturn as a yellowish oval because of the rings.

BETA PERSEI STAR SHOW
Beta Persei, better known as the star Algol, is an eclipsing binary star system with a period of 2.87 days. Every 2.87 days the brighter of the two stars is eclipsed by the dimmer star. This causes the star to vary in brightness from mag. 2.1 to mag. 3.4. However, only some of the eclipses are visible during the night from any one location. During this month, watch Algol dip in brightness on Oct. 19, 22, and 25. Algol is located 100 light-years from Earth. Its primary components are a blue giant star (spectral type B8V) and a yellow dwarf star (spectral type G). Long-term observations of the stars' movements have shown that there are actually more than two stars in this system, but little is known about the other components.

METEOR SHOWERS
OCTOBER DRACONIDS - Also called the Giacobinids, this shower is caused by dust from Comet Giacobini-Zinner. Meteors from the October Draconid shower may be visible from October 7 to 10. The shower peaks on October 8/9. The rate of the shower is variable and the peak lasts only a few hours. This shower gives a good display only when the parent comet returns to perihelion, which is every 6.5 years. The meteors will appear to originate from a point in the sky near the head of the constellation Draco, the Dragon.

ORIONIDS - This shower is caused by dust from Halley's Comet, which is also responsible for the Eta Aquarid Shower in the spring. Meteors from the Orionid shower may be visible throughout the month of October and through the first week of November. The maximum will probably last from the 19th through the 23rd, with the peak around the 22nd. At its height the shower should produce 15 to 20 meteors per hour. The meteors will appear to originate from a point in the sky between the constellations Gemini and Orion, high in the southern sky during the October evenings. The Hunter's Moon on October 24 will affect viewing of this year's Orionid shower. The overwhelming brightness of the moon will leave only the most spectacular members of the shower visible to dedicated observers.

TAURIDS - Much of the dust from this shower is caused by Periodic Comet Encke. Meteors from this shower may be visible from Oct. 20 through Nov. 30. The meteors will appear to originate from two points in the constellation of Taurus (RA 03 hrs 44 min, Dec +14° and RA 03 hrs 44 min, Dec +22°).

OBSERVING: Meteors are best viewed from a dark-sky location. Observers in for the duration of the evening, or at least for several hours, should bring along a few things: a sleeping bag or blankets for warmth, a recliner or lawn chair, a hot beverage to help cut the chill, and binoculars to view the smoke trails of just-past meteors.

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