In The Sky This Month – March 2009
March 1, 2009 5 Comments
This feature highlights a number of meteor showers, comets and asteroids which are visible during the month of March 2009. This month sees the end to Venus’ reign over the evening sky. Also Comet Lulin should continue to be bright enough for easy evening observation.
Note: If anyone has pictures or observations of these objects/events and want to share them, send me a comment. I’ll post them here.
Venus has been putting on quite a display for the past few months in the evening sky. Unfortunately, the show comes to an end this month. At the beginning of the month, Venus is still riding high in the western sky after sunset. As the month progresses, it will appear lower and lower in the sky. Most people will have a hard time seeing it by mid-month. On March 27, Venus will pass between closest to the Sun. After that date, it will become a morning object. Early hour risers will witness Venus in all of its glory for most of the rest of the year.
This month Saturn will at opposition. The exact date being March 8. Opposition is when a planet (or comet or asteroid) is located opposite the direction of the Sun. On this date, Saturn will be closest to Earth and at its brightest. It rises at sunset and by 9pm is high enough to be easily seen. Even at its brightest, Saturn is not as brilliant as Venus or Jupiter. Still at magnitude +0.5, it is brighter than all but the 9 or 10 brightest stars.
This opposition is actually one of Saturn’s dimmest. The reason is that the rings of Saturn contribute a lot to the brightness of Saturn. But this year, is a ring plane crossing year meaning that the rings are nearly edge-on. As a result, the rings are reflecting much less light in the Earth’s direction this year.
Jupiter and Mars are located near each other low in the early morning sky. As the month progresses Jupiter will become easier and easier to see. At magnitude -2.1, Jupiter is brighter than any star in the sky. Mars on the other hand will only be visible to those with a clear view of the southeastern horizon. At magnitude 1.2, Mars would just crack the Top 20 in brightest stars in the sky.
Mercury is still visible low in the east just before dawn. Due to the angle of the ecliptic with the morning eastern horizon this month, Mercury is a very difficult object to observe from the Northern Hemisphere but an easy object from the Southern Hemisphere. It will be lost to Northern observers a few days into the month. Southern observers will be able to follow it till a bit past mid-month.
The month of March experiences no major showers and only a few minor ones. It continues the annual lull in meteor activity from mid-January to mid-April.
Sporadic meteors are not part of any known meteor shower. They represent the background flux of meteors. Except for the few days per year when a major shower is active, most meteors that are observed are Sporadics. This is especially true for meteors observed during the evening. During November, six (6) or so Sporadic meteors can be observed per hour from a dark moonless sky.
Major Meteor Showers
Minor Meteor Showers
Minor showers produce so few meteors that they are hard to notice above the background of regular meteors.
Delta Leonids (DLE)
The Delta Leonids are another minor shower with a period of activity from February 15 to March 10. Near its February 25 peak, rates may reach a paltry 2 per hour.
Gamma Normids (GNO)
This shower is best from the Southern Hemisphere since it radiates from the southern constellation of Norma. Observers north of +40 deg North will not be able to see any GNOs. Then again it is such a minor shower that there is doubt whether it even exists!
The shower spans from Feb 25 to March 22 with a peak around March 13 with a maximum ZHR of 4.
Additional information on these showers and other minor showers not included here can be found at the following sites: Robert Lunsford’s Meteor Activity Outlook, Wayne Hally’s and Mark Davis’s NAMN Notes, and the International Meteor Organization’s 2008 Meteor Shower Calendar.
Naked Eye Comets (V < 6.0)
Comet Lulin starts the month as a barely naked eye comet at magnitude 5. More on this comet can be found in the next section.
Binocular Comets (V < 8.0)
Comet C/2007 N3 (Lulin)
Comet Lulin was discovered by the Lulin Sky Survey in Taiwan on 2007 July 11. At the time the comet was located beyond the orbit of Jupiter. The comet will be closest to the Sun on 2009 January 10 at 1.21 AU from the Sun. It will be closest to Earth in late-February when it will be only 0.41 AU from us.
The comet is currently around magnitude 5.2 which makes it an easy object for binoculars and small telescopes from a dark sky. From a dark rural moon-less sky, it can even be seen with the naked eye. Over the course of the month, the comet will fade from naked eye view but still be bright enough for binocs/small telescopes. By the end of the month, Lulin will be close to 7th magnitude.
After a few months as a morning object, Lulin spends all of March visible in the evening. Due to its retrograde orbit, the comet is moving in almost the exact opposite direction as the Earth. As a result, it is rapidly moving to the west every night. Over the course of the month, Lulin will start the month in western Leo, cross Cancer and end in the middle of Gemini.
A finder chart for Comet Lulin can be found at Comet Chasing.
Small Telescope Comets (V < 10.0)
Comet C/2006 W3 (Christensen)
This comet was discovered over 2 years ago on 2006 November 18 by Eric Christensen of the Catalina Sky Survey north of Tucson. At the time the comet was located at 8.7 AU from the Sun which is nearly the distance of Saturn. The comet continues to move closer to the Sun and Earth and is currently 3.8 AU from the Sun and 3.4 AU from the Earth.
The comet is currently around magnitude 9.7 and will slowly brighten during the month. It is moving near the border of Lacerta and Pegasus. The comet is best seen in the early morning. I was able to observe the comet visually with my backyard 12″ reflecting telescope in November. Being small and condensed, the comet was fairly easy to see.
The comet will continue to brighten as it approaches perihelion at a still rather distant 3.12 AU from the Sun on 2009 July 6. At that time, the comet will be 8th magnitude and visible in many smaller backyard telescopes and even binoculars from dark sites. Christensen should remain bright enough to see in modest sized backyard telescopes for all of 2009.
A finder chart for Comet Christensen can be found at Comet Chasing.
Comet Kushida was discovered by Japanese amateur astronomer Yoshio Kushida back on 1994 January 8. With an orbital period of 7.6 years, this year marks its 3rd appearance since discovery.
The comet was not expected to get brighter than magnitude 10 or 11 but recently observers have estimated it is as bright as magnitude 9.1. With perihelion this January 26 at 1.44 AU from the Sun, the comet should start to rapidly fade. The comet starts the month near the border of Taurus and Orion before moving across the “club” of Orion and into Gemini.
A finder chart for Comet Kushida can be found at Comet Chasing.
Binocular and Small Telescope Asteroids (V < 10.0)
Ceres is the biggest asteroid in the Main Belt with a diameter of 585 miles or 975 km. It is so big that it is now considered a Dwarf Planet. Classified as a carbonaceous (carbon-rich) Cg-type asteroid, there are suggestions that it may be rich in volatile material such as water. Some even propose that an ocean exists below its surface. Ceres is one of two targets for NASA’s Dawn spacecraft which is scheduled to visit it in 2015. Last month Ceres was at opposition (at its closest to the Earth and at its brightest). This month Ceres will fade from from magnitude 6.9 to 7.4 as it moves into Leo Minor, just north of Leo. If you are observing Saturn with a telescope or pair of binoculars, try your hand at finding Ceres with one of the finder charts linked below.
Pallas is also a carbonaceous asteroid though with a slightly bluish B-type spectrum. Due to its high inclination (tilt of its orbit with respect to Earth’s orbit) of 34 degrees it is a difficult target for future spacecraft missions. Pallas is large with dimensions of 350x334x301 miles or 582x556x501 km. This month it continues moving north, leaving the constellation of Lepus and entering southern Orion. It fades from magnitude 8.4 to 8.7 over the course of the month.
Though not as large as Ceres, Vesta is more reflective making it the brightest asteroid in the Main Belt. Vesta is peculiar in that it appears to have evidence of volcanism on its surface. Similar to the Moon, Vesta may be covered with large expanses of frozen lava flows. It is classified as a V-type asteroid and is the only large asteroid with this classification. Many of the smaller V-type asteroids are chips of Vesta blasted off it by past asteroid and comet impacts. Vesta is similar in size to Pallas with dimensions of 347x336x275 miles or 578×560×458 km. Vesta will also be visited by NASA’s Dawn spacecraft which will arrive in 2010. On October 30, Vesta was at opposition (directly opposite from the Sun in the sky) and at its brightest. This month Vesta is an evening object moving through Aries before entering Taurus near the end of the month. It will fade from magnitude 8.3 to 8.5.
Irene was discovered by John Russel Hind in 1851, being only the 14th asteroid known at the time (if you are wondering ~400,000 asteroids have been discovered to date, we’ve come a long way). It is an S-type asteroid with a stoney or silicate composition. Its takes 6.3 years to orbit the Sun.
This month Irene will brighten from magnitude 9.9 to 9.2 as it travels through Virgo. Next month it will reach its brightest on April 21 at magnitude 8.9.
Euterpe was the 27th asteroid discovered when it was first seen in 1853. It is an S-type asteroid with a stoney or silicate composition. With a diameter of 58 miles (96 km) it is much smaller than Ceres, Pallas or Vesta. The reason it can get as bright as them is due to its orbit which brings it closer to the Sun and Earth. This month Euterpe will be roughly 1 AU from Earth and 2 AU from the Sun.
This month Euterpe is located in Cancer not far to the east of the Beehive Star Cluster. It starts the month at magnitude 9.7 and fades to 10.5 making this an object for advanced observers.
Discovered in 1854, Amphitrite was the 29th asteroid to be discovered. Similar to Euterpe, Amphitrite is also a stoney S-type asteroid. With an average diameter of 127 miles (212 km) it is bigger than Euterpe though its further distance from the Earth and Sun keeps it from getting as bright.
Ampitrite reaches it brightest for the year on March 22 at magnitude 9.1. It starts the month at mag 9.7, brightens to 9.1 at opposition and fades back to 9.4 at month’s end. It spends the entire month in Virgo.