It may seem a little early for Christmas, but here in Duluth the extensive Bentleyville holiday lighting display – including a 120-foot tall metal Christmas tree -Â is under construction near the harbor in Bayfront Park. Last night the crescent moon joined the scene as volunteers were testing out the LED lights on the tree. It’s fun to catch the moon in a cityscape, where we witness the meeting of two worlds so different from each other.
The occultation of a faint star by Eris on November 6th, 2010. The observation was made with a robotic telescope from the Andalusian Astrophysics Institute located in Chile. The star blinks out as Eris passes in front and then returns to view as the dwarf planet moves on.
It appear that Pluto, which was demoted to dwarf planet status several years ago, and then further demoted to second place in size among the dwarfs, may soon get its come uppence. Previously, the dwarf planet Eris, located three times farther from the sun than Pluto, was estimated to be slightly larger than the erstwhile planet. Eris and Pluto are both members of a distant swarm of asteroids beyond Neptune called the Kuiper (KY-per) Belt.
On November 6, three observing teams in Chile watched a faint star briefly disappear from view as Eris passed in front of it, an event called an occultation. By carefully timing the star’s disappearance from three different locations, astronomers were able to determine a new estimate of Eris’ diameter. Turns out it’s shy of Pluto’s size by at least a few to a few tens of kilometers. For now, Eris is somewhat smaller than 1,454 miles in diameter while Pluto wears the crown at 1,456 miles. Pluto-as-planet lovers have reason to celebrate even if the orb’s status still remains dwarfish. Read more about the occultation HERE.
There might be news of activity in Jupiter’s South Equatorial Belt (SEB), the stripe that faded away to almost nothing earlier this year. Philippine amateur Christopher Go recorded a small bright spot in the belt early this morning. Sometimes a spot like this one is the beginning of what observers call the SEB revival. It’s the Jovian equivalent of the hootin’ and hollerin’ at an old-fashioned tent revival, except involving multiple spots that appear rapidly in succession. They funnel fresh, darker materials from beneath the cloud tops into view. In short order, these coalesce and a new dark belt takes shape in place of the pale version we’re now seeing. Amateurs will be watching Jupiter closely in the coming days for signs of more activity. Here are a few more of Chris’s photos.
Tonight you can see at least three of Jupiter’s bright moons through your binoculars. The 4th one, Io, will be very close to the planet’s western edge early in the evening and difficult to make out in Jupiter’s glare. If you wait until later – around 9 or 10 – it will have orbited farther out and be easier to spot. Observers with telescopes can watch Io’s shadow crossing over Jupiter’s cloud tops until about 6:50 p.m. Central time. The best time is between 5:30 and 6 when the sky’s getting dark and the shadow is more centrally located. Use medium to high magnification and look for a small black dot.