Astroblog: Seeing Vesta at Opposition (23 August 2022)

Wednesday, August 17, 2022

Seeing Vesta at Opposition (23 August 2022)


The North-east horizon as seen from Adelaide at 20:00 ACST (8:00 pm) showing the location of Vesta (click to embiggen) on Tuesday, August 23, when Vesta is at opposition and at its brightest.Similar views will be seen elsewhere in Australia at the equivalent local time.	The approximate binocular view of Vesta and the four guide stars at 20:00 ACST (8:00 pm) on Tuesday, August 23. The helix nebula is shown but will not be visible in binoculars(click to embiggen, similar views will be seen elsewhere at the equivalent local time).

Black and white horizon chart facing east suitable for printing showing the guide objects of 4 Vesta Saturn and Fomalhaut as seen from Adelaide at 22:00 ACDST. Similar views will be seen elsewhere in Australia at the equivalent local time. Use the charts above to orient yourself to get to the guide stars.	Black and white binocular chart suitable for printing showing the movement of 4 Vesta over August. The large circle represents the field of view of 10x50 binoculars. Click to embiggen and print. Use the horizon chart to the left for orientation first.

The Asteroid 4 Vesta is one of the iconic minor planets, and one of two orbited by the Dawn spacecraft. At favorable oppositions Vesta is bright enough to be seen with the unaided eye under dark sky conditions. This year it gets to magnitude 5.8 just over unaided eye visibility at dark sky sites. Not really visible from suburban skies, but it will be easily visible in binoculars and small telescopes.

This year on Tuesday, August 23 is a okay opposition of Vesta, when it will reach a magnitude of 5.8 at its brightest with reasonable guide stars. The next bright opposition is May 2025 it will reach magnitude 5.6 with good guide stars.

This year Vesta has some reasonable signposts to it, just before and just after opposition Vesta is roughly between the bright planet Saturn and the bright star Fomalhaut. In binoculars if you star hop from Saturn to iota Aquarii (see binocular charts above), then about two binocular widths from iota Aquarii to 66 Aquarii (the next brightest star, also labelled as g1 Aqr in the stellarium chart), upsilon (υ) Aquarii will also be in the same field. Vesta is in the same binocular field as 66 and Upsilon (and then Upsilon and 47) Aquarii. Vesta is the brightest object aside from Upsilon, 66 and 47 Aqr and its movement from night to night easily seen.

Finding Vesta with the charts should be easy. Print them out and use with a red-light torch (or a standard torch with red cellophane over it) so as to not disturb your night vision.

The Full Moon interfered significantly early on earlier in the month, but now the skies are free from interference. Just before opposition, at opposition and several days after opposition Vesta is bright and easily seen. 17 August to 4 September may be best.

Labels: 4 Vesta, Asteroid, binocular, unaided eye