Serious About Ceres? Vested In Vesta? A Last-minute Conjunction Guide

Last night July 2, 2014 Ceres and Vesta were about a quarter degree apart in Virgo above Mars and Spica in the southwestern sky around 11 p.m. You can clearly see that Vesta is the brighter asteroid. 70mm lens at f/2.8, ISO 2500, 15-second exposure. Credit: Bob King

And yes the twain shall meet! Tonight I have a couple new photos to share with you showing the asteroids Ceres and Vesta just before their face-to-face meeting on July 5. That night they’ll be 10 arc minutes or just a third of a full moon diameter apart. Don’t fret if the weather’s supposed to be cloudy then – they’ll be nearly close tonight through the 6th.

Ceres and Vesta on the move! Pictures taken last night July 2, 2014 and tonight July 3 around 11 p.m. CDT show both asteroids zipping along near Zeta Virginis. The small triangle of stars serves as a reference to help you judge their movement. Photos taken with a 70mm lens, enlarged and cropped. Credit: Bob King

Besides, tonight the moon’s still a crescent and neither as bright nor as close to our asteroidal celebrities as it will be on the 5th. Glare that night will make seeing fainter Ceres difficult. If you have a telescope, both can be viewed right on through the full moon.

Map showing the motion of Ceres and Vesta at 1-day intervals near Zeta Virginis, a 3rd magnitude star located above the bright pair of Mars and Spica in the southwestern sky at nightfall. They’ll be closest on July 5. Stars plotted to magnitude 8.5. I also drew in the same triangle as in the photos. Source: Chris Marriott’s SkyMap

Vesta shines at magnitude 7, one magnitude fainter than the naked eye limit. I had no problem seeing either asteroid in 8×40 binoculars last night (July 2). They also showed up in my camera with a 15-second exposure at ISO 2500 with the lens wide open at f/2.8. The next few nights present a great opportunity for anyone with a medium to higher end digital camera and tripod to create a series of photos showing their convergence and divergence over time. A animated gif of the motion would be sweet!

Ceres and Vesta through a 14-inch telescope on July 3, 2014 when they were 13 arc minutes (a bit less than a 1/4 of a full moon diameter) apart. Both asteroids are too small and far away to appear as real disks in most telescopes. Credit: Gianluca Masi

Italian astronomer Gianluca Masi plans to feature live telescope images of Ceres and Vesta at closest approach on his Virtual Telescope site beginning at 3 p.m. CDT (4 p.m. EDT, 2 p.m. MDT and 1 p.m. PDT) Saturday July 5.

Hope you get to see the pair. Their last conjunction was in 1996 when they were much farther apart (2 degrees). And don’t forget the nearby conjunction of the moon and Mars with Spica nearby the same night.

4 Responses

  1. Edward M. Boll

    Somewhere in the same brightness of the asteroids sits Comet Catalina, quickly brightening this week and circumpolar. It really moves across the sky this next week, highest in the sky at Dawn on the 8th and at dusk on the 15th.

    1. astrobob

      Hi Edward,
      I’ve been watching it the past few nights in the 15-inch. Very diffuse, about mag. 10. Doing well as a comet after graduating from asteroid school.

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