Vesta is passing an 8th-magnitude field star, offering a great opportunity to see the space rock’s motion on the sky over just a few nights.
This chart shows the position of Vesta over the course of a few days. If you come back for a few days, you can easily see Vesta’s motion relative to the field star HD 130193. Credit: Alison Klesman (via TheSkyX)
- Asteroid 4 Vesta, a 7th-magnitude object, presents an observable positional shift relative to nearby stars in the constellation Libra, specifically near HD 130193 and Xi1 Librae.
- Vesta’s apparent motion provides an opportunity for observation and tracking against the static stellar background over several days.
- The globular cluster NGC 5634 in Virgo, with an apparent magnitude of 9.6, is highlighted as an observable target, suggested to originate from a Milky Way satellite galaxy.
- Observational timing information is provided for sunrise, sunset, moonrise, moonset, and moon phase (waxing crescent at 33% illumination) at a specified location (40° N 90° W).
Asteroid 4 Vesta remains an easy-to-spot target in western Libra, just 5° north of Zubenelgenubi, the Balance’s double alpha star. Tonight and tomorrow offer an excellent opportunity to see the 7th-magnitude space rock move relative to the background of stars, as it currently lies less than 0.5° from a slightly fainter 8th-magnitude background star (HD 130193).
Tonight, Vesta is 10.5’ northwest of that star. Tomorrow, it is a little less than that distance roughly due east of it. Vesta is also drawing closer to 6th-magnitude Xi1 (ξ1) Librae and will sit due south of this star on August 6, offering another chance to easily catch the asteroid moving against the stationary background for a few days before and after this date.
While you’ve got your scope out, swing up 6.7° northwest into Virgo to enjoy NGC 5634, a lovely compact globular cluster that shines at magnitude 9.6. Astronomers believe this cluster was once part of one of the Milky Way’s smaller satellite galaxies, likely the the Sagittarius Dwarf Elliptical Galaxy or the Sagittarius Dwarf Spheroidal Galaxy. Its brightest star, 8th-magnitude SAO 139967, is just southeast of the cluster’s center. The markedly orange-hued sun stands out distinctly against the fuzzy background created by the compact structure of the grouping.
Sunrise: 5:57 A.M.
Sunset: 8:15 P.M.
Moonrise: 12:00 P.M.
Moonset: 11:05 P.M.
Moon Phase: Waxing crescent (33%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.
For a look ahead at more upcoming sky events, check out our full Sky This Week column.