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Centaur
2012-Sep-03, 01:19 AM
Iíve added a new feature on my asteroid webpage that I hope you may find interesting and useful. Itís a one-year graph for the stellar magnitudes of the fifteen brightest asteroids. It can be seen at www.CurtRenz.com/asteroids

Centaur
2012-Sep-05, 06:39 PM
I'm hearing from friends about the graph. Some were surprised that Ceres' peak brilliance is so near in both magnitude and time to that of Vesta. That's an oddity this year. While Ceres is the largest asteroid, Vesta is well known to be the brightest for earthbound observers. Indeed, Ceres is still an asteroid even though it is also classified as a dwarf planet.

I ran a test for the period 1912 to 2112. At oppositions the magnitude of Ceres varies between 6.7 and 7.7. For Vesta the opposition range is 5.2 to 6.5. The brightest oppositions for Ceres are those in mid-December. The dimmest oppositions for Vesta are those in mid to late November.

The timing differences relate to the longitudes of their perihelia. Of course the two have different orbital periods, so it's just a coincidence that their oppositions both occur in December this year.

Bynaus
2012-Sep-06, 03:33 PM
Nice. It's just a bit difficult for me to tell all the different colors apart (not for Vesta & Ceres, okay...). I think it would be enough to add the asteroid number at some point to each graph.

Centaur
2012-Sep-06, 06:11 PM
Nice. It's just a bit difficult for me to tell all the different colors apart (not for Vesta & Ceres, okay...). I think it would be enough to add the asteroid number at some point to each graph.

Thanks for your suggestion, Bynaus. I considered that earlier. However the addition of numbers or letters makes the chart appear even more cluttered. I suppose I could reduce the number of asteroids.

I'll note that if you check the list of linked asteroid charts on my asteroid webpage, you will see the magnitudes of the asteroids at the dates of their greatest brilliance. That should help you to deduce which graph line applies to each asteroid. Not all of the brightest asteroids are currently listed on that webpage, but they will be added or deleted depending on whether they are in the better portion of their apparitions.

I'll add a clarification that the NEOs 433 Eros and 1036 Ganymed do not appear in the current set of graphs, since they do not reach the magnitude threshold during the time period of the chart. I've now removed their numbers, names and colors from the listing at the left of the chart, and adjusted the brightness of the colors for some of the others. I hope this reduces confusion.