Will Sirius Disappear on February 18th?
On Monday evening observers in components of Mexico, the western U.S., and central Canada may even see the occultation of a lifetime when a tiny asteroid momentarily blots out the evening sky’s brightest star. The asteroid 4388 Jürgenstock could occult the evening sky’s brightest star, Sirius, for observers in components of Mexico, the western U.S.,
On Monday evening observers in components of Mexico, the western U.S., and central Canada may even see the occultation of a lifetime when a tiny asteroid momentarily blots out the evening sky’s brightest star.
The asteroid 4388 Jürgenstock could occult the evening sky’s brightest star, Sirius, for observers in components of Mexico, the western U.S., and south-central Canada.
Can a 7-kilometer-wide asteroid make Sirius disappear? You guess it may. That simply may occur on Monday evening, February 18th. That night round 10:30 p.m. MST (5:30 UT February 19th), there is a good chance that the 17th-magnitude 4388 Jürgenstock will occult the sky’s brightest star for as much as 1.Eight seconds. Visibility stretches alongside a slim path from the southern tip of Baja California to the Las Cruces–El Paso area, up via the Nice Plains, and north to the Winnipeg space. Whereas solely a restricted variety of individuals may even see this occasion, anytime Sirius disappears, nonetheless briefly, it is information!
The explanation for the uncertainly lies in not having a exact place nailed down for Sirius. The latest Gaia Mission plotted a billion star positions to an accuracy of lower than zero.0001 arcsecond, ultimate for dead-on occultation predictions. However Sirius could not be measured as a result of its singular brilliance oversaturated Gaia’s detector.
The anticipated visibility zone lies within the slim 18-kilometer-wide hole between the double darkish strains. The outer dashed strains outline the outer restrict of the occultation in case of a 1-sigma error within the predicted path both east or west. 4388 Jürgenstock is called for Venezuelan astronomer Jürgen Inventory, who died in 2004.
Mockingly, whereas Gaia could not pinpoint Sirius’s place, astronomers analyzing the sky across the star found a hitherto unknown, huge star cluster hidden in its glare. Gaia 1, situated 10′ (arcminutes) east of the Sirius and 15,000 light-years away, has eluded skywatchers for hundreds of years! Even the 1991 Hipparcos mission struggled with Sirius, however regardless of some uncertainty it produced fairly good information.
The Gaia 1 cluster was found in 2017 by astronomers utilizing information from the Gaia Mission. It is 13′ vast, fairly wealthy, and about 15,000 light-years away.
ESA / Gaia
Assuming the occultation happens, the asteroid’s tiny measurement (zero.007″) is simply barely bigger than the disk of Sirius (zero.0060″). In line with David Dunham with the Worldwide Occultation Timing Affiliation (IOTA), the star could utterly disappear on the centerline for a mere zero.2 seconds of the 1.Eight-second-long occasion. Observers will see Sirius fade, clean out solely momentarily, then brighten to full brilliance. Since Jürgenstock is more likely to have an irregular form and may very well be just a little bigger or smaller than predicted, there’s an opportunity that Sirius may blink-out for longer or shorter than anticipated, or fail to utterly disappear.
There’s additionally a little bit of fuzziness concerning the asteroid’s place, which could alter the timing and path barely. Deliberate observations by JPL’s Desk Mountain Observatory earlier than Monday (climate allowing) will tighten up these parameters. If there are updates or adjustments, I’ll submit them right here ASAP and make a remark on the prime of the weblog. Make sure to verify again in the event you’re in or close to the trail.
Think about the evening sky with out Sirius — even briefly!
The Moon will probably be practically full Monday night with Sirius nicely positioned within the southwestern sky on the time of the occultation. Observers are inspired to make timings of the occasion to assist get a repair on Sirius in addition to glean particulars concerning the asteroid and its orbit. Sirius can exhibit violent twinkling — let’s hope for serene air lest atmospheric turbulence masks what may very well be probably the most superb occultation in a very long time.
Dunham has numerous further info together with sectional maps and instances for particular cities. Test these hyperlinks for extra particulars:
Coincidentally, a second occultation happens earlier on Monday morning, February 18th, simply after 12:30 UT (6:30 a.m. CST) when the 37-kilometer-wide asteroid 396 Aeolia covers four.2-magnitude Chi (χ) Virginis for about 11 seconds. Chi is situated 11° west of Spica; the trail crosses southern Texas and northern Mexico. Click on right here for particulars.