What’s Up?
The Sky This Week
- Thursday, September 6
- The tumbling Iridium 44 satellite will move from S to N from about 8:28 to 8:39 p.m. It will reach its highest point in the sky (74 degrees altitude) around 8:33 p.m., near the Keystone of Hercules.
- Saturday, September 8
- Delta Aurigid meteors (6 meteors per hour, or less).
The Sun's north pole is tilted most towards the Earth (7.25 degrees).
The asteroid 129 Antigone (magnitude 10.9) will occult the star SAO 165635 (magnitude 8.4) in Aquarius at 11:16 p.m. Use a telescope.
- Monday, September 10
- Saturn is very near the Moon this morning before dawn.
Saturn disappears behind the Moon at 7:45 a.m. (bright limb, left side, upper quadrant); it reappears at 8:59 a.m. (dark limb, right side, lower quadrant). Use a telescope.
Last Quarter Moon.
The Iridium 38 satellite will flare to -8 magnitude around 8:08 p.m. at azimuth 356 degrees (N) and altitude 44 degrees.
- Tuesday, September 11
- The Hubble Space Telescope will move from SSW to SSE from about 8:36 to 8:40 p.m. It will reach its highest point in the sky (14 degrees altitude) around 8:38 p.m., just below the teapot of Sagittarius. Use binoculars.
- Wednesday, September 12
- The Moon rises at its most northerly point along the eastern horizon this month at 12:57 a.m.
Jupiter is very near the Moon this morning before dawn.
The Hubble Space Telescope will move from SSW to SSE from about 8:40 to 8:44 p.m. It will reach its highest point in the sky (14 degrees altitude) around 8:42 p.m., just below the teapot of Sagittarius. Use binoculars.
* All times given are for CST (Central Standard Time), so you may need to adjust some given event times to your viewing location: -2 hours Pacific, -1 hour Mountain, +1 hour Eastern, etc.
The waning last-quarter Moon will rise along the E-NE horizon at 11:21 p.m. Sunday night, followed soon after by "The Lord of the Rings", the planet Saturn, at 11:33 p.m. Throughout the rest of the night, the two empyrean orbs will come closer and closer to one another until the Moon actually passes in front of Saturn after sunrise Monday morning.
The Moon passed in front of Mercury and Venus in July, Jupiter in August, and now it's Saturn's turn in September. Here in Iowa, where it is cloudy two-thirds of the time, clouds prevented our seeing the Mercury, Venus, and Jupiter occultations. Fortunately, September is the clearest month of the year in Iowa, so that improves our chances of seeing Saturn covered up and then uncovered by the Moon as it orbits the Earth.
This event will be difficult to observe, however. Saturn is dimmer than Mercury, Venus, and Jupiter, so it will be much harder to see the ringed planet next to the Moon in broad daylight. A telescope and patience will be needed.
Since Saturn is 93 degrees away from the Sun at the time of the event, an eyepiece polarizing filter can be used to darken the sky background. The light of the blue sky is most highly polarized at an angle of 90 degrees from the Sun, so by rotating an eyepiece with a polarizing filter in it you can find an orientation that darkens the sky considerably, making it easier to see the planet. I used this technique with great success to observe the Comet Shoemaker-Levy 9 impact sites on Jupiter in broad daylight from my backyard in July 1994.
As the Moon continues its eastward orbital trek around the Earth, it will come very close to the planet Jupiter on Wednesday morning.
The asteroid 129 Antigone as it orbits the Sun will pass in front of the star SAO 165635 in Aquarius Saturday evening. While the star's light is blocked, the asteroid will project a dim moving shadow upon the surface of the Earth that is the exact size and shape of the asteroid. The maximum duration of the event will be about 10 seconds for observers in the center of the shadow; during the time the star is covered up there will be nearly a three magnitude drop in brightness as only the asteroid will be seen. By accurately recording the time and duration of the event, and knowing your exact location on the Earth, your observation can be combined with those of other observers to determine the size and shape of the asteroid. For more information, including detailed finder charts, see here.
Enjoy!
The Sky This Week is written by David Oesper, and produced weekly by NetDNS - seeNstars for National Public Observatory.
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