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Watch Asteroid Take the Bull by the Horns

n this artist's concept, an asteroid belt filled with rocks and dusty debris orbits a star similar to our own sun.Sky-watchers get to see one of the larger asteroids in our solar system this month. Image credit: NASA/JPL-Caltech

In this artist’s concept, an asteroid belt filled with rocks and dusty debris orbits a star similar to our own sun. Sky-watchers get to see one of the larger asteroids in our solar system this month. Image credit: NASA/JPL-Caltech

A glimpse of a large asteroid comes to delight sky-watchers this month, silently sailing its way through a cosmic bull’s horns and past a famous supernova remnant.

In the next few weeks, the asteroid Herculina, the 532nd asteroid to be discovered, will glow in the sky at a magnitude of brightness of about 10. That should make it easy to spot with small backyard telescopes, even through the glare from cities.

This 140-mile-wide (230-kilometer-wide) space rock is in the top 20 of the largest asteroids known to reside within the main belt of asteroids that lies between Mars and Jupiter. It has a surface that appears brighter than that of Earth’s moon, but because of its distance—normally some some 260 million miles (400 million kilometers) away from Earth—it lies beyond the reach of most backyard astronomers.

Now, however, thanks to its elliptical orbit, Herculina will come as close as 160 million miles (250 million kilometers) away from our planet, offering us a golden opportunity to observe an otherwise tough stargazing target.

Herculina is located very close to Zeta Tauri star that marks the tip fo the southern horn of Taurus, the bull. The constellation is easy to find thanks to the bight orange star Aldebaran in the southwest in the early evenings this time of the year. Credit: Starry NightSoftware/ A.Fazekas

Herculina is located very close to Zeta Tauri, the star that marks the tip of the southern horn of Taurus, the bull. Thanks to the bright orange star Aldebaran, the constellation is easy to find in the southwest in the early evenings this time of  year. Credit: Starry Night Software/A. Fazekas

To add Herculina to your astronomical bucket list, use the sky chart above to locate its approximate position in the constellation Taurus, the Bull.

Start at the bright orange beacon of Aldebaran, the eye and the tip of the distinctive V-shaped face of Taurus, which is now riding high in the southwestern sky in the early evening.

Through the first half of February, the asteroid is whizzing by Zeta Tauri, the magnitude-3 star that marks the tip of the southern horn of the bull.

On the nights of February 5, 6, and 7, Herculina will be its closest to Zeta Tauri, making the star a wonderful guidepost for locating it.

This detailed finders chart shows the daily path of Herculina as it passes beside Zeta Tauri and then the Crab Nebula in February. Credit: Starry Night Software / A.Fazekas

This detailed finders chart shows the daily path of Herculina as it passes beside Zeta Tauri and then the Crab Nebula in February. Credit: Starry Night Software / A.Fazekas

Because many of the stars in your field of view through your telescope’s eyepiece will probably look the same, the best way to identify an asteroid is by its telltale motion. But since asteroids this far away from Earth don’t appear to move across the sky over the course of a few minutes or even hours, identifying their subtle presence will take a little patience. Sketch the position of about a dozen stars you see through your telescope’s eyepiece. Then a couple of nights later, observe the same starfield and do the same thing. The one “star” that has moved is Herculina.

Catching the Crab

This is a mosaic image, one of the largest ever taken by Hubble Space Telescope of the Crab Nebula,  Japanese and Chinese astronomers recorded this violent event nearly 1,000 years ago in 1054, as did, almost certainly, Native Americans.Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)

This mosaic image of the Crab Nebula is one of the largest ever taken by the Hubble Space Telescope. Japanese and Chinese astronomers noted the explosion of this supernova nearly a thousand years ago in 1054, as did, almost certainly, Native Americans. Credit: NASA, ESA, J. Hester, and A. Loll (Arizona State University)

Then around Valentine’s Day next week, look for Herculina to pass by one of the most famous stargazing targets for backyard scopes—the supernova remnant known as the Crab Nebula, or Messier 1.

At the closest approach on the 14th, Herculina and the Crab will appear only 30 arc-minutes apart—a width equal to the disk of the full moon in the sky.

Instruments as small as binoculars will pick up the 8th-magnitude fuzzy oval glow of the supernova remnant only about a degree above Zeta Tauri. It will appear in the same field of view under low magnification in your telescope.

On and around the 14th of February the large asteroid Herculina will appear to glide past the famous Crab Nebula,  with the two separated by only 30 arc-minutes. Credit: Starry Night Software / A.Fazekas

On and around February 14, the large asteroid Herculina will appear to glide past the famous Crab Nebula, with the two separated by only 30 arc-minutes. Credit: Starry Night Software/A. Fazekas

It’s amazing to think that the Crab Nebula is a cloud of debris 6,500 light-years away. Measuring nearly 11 light-years across and still expanding, the nebula is all that is left of a giant star that appeared to explode in Earth’s skies back in the year A.D. 1054.

The blast was so bright and powerful that Chinese astronomers at the time made note of this “guest” star, which appeared as bright as Venus for 23 days.

For more celestial sights, check out our weekly sky-watching column.

Follow Andrew Fazekas, the Night Sky Guy, on Twitter,  Facebook, and his website.

Comments

  1. wilson
    uae
    February 10, 11:01 am

    pls send good pic

  2. David
    February 9, 7:08 pm

    Luis Reyes: that’s the planet Venus.
    A good idea is to download the free planetarium software “Stellarium”, set it to your location, and you will be able to know what can you see on the sky at any time, day or night.

  3. LUIS REYES
    MICHOACAN. CENTRAL MEXICO
    February 9, 2:14 pm

    LAST COUPLE OF DAYS NOTICE THE BRIGTHTEST OBJET IN SKY ABOUT 6:00 AM DON´T KNOW WHAT IT IS. IST A STAR…AN THE POSITION IS N. E. ALMOST WERE THE SON COMES OUT IN THE MORNING…

  4. mohsen hoseini
    iran
    February 9, 12:51 pm

    please for me and answer my letter