Hubble looks but finds no trace of comet ISON

Dec 23, 2013 by Bob King, Universe Today
Each of the four panels is a combination of two separate exposures made by the Hubble Space Telescope as it tracked Comet ISON’s position. Had the comet been in any of these frames, it would have appeared as a small fuzzy glow or stellar point(s) in the center. Credit: NASA/ESA

On December 18, the Hubble Space Telescope slewed to Comet ISON's expected position and found nothing down to the incredibly faint magnitude of 25. According to astronomer Hal Weaver, who planned the ISON search, that limit implies any remaining fragments would have to be smaller than about 500 feet (160 meters) in diameter.

Nothing is visible in any of the images in the photo panel except trailed stars and galaxies, reflections and the occasional zap of a . After ISON was torn asunder by the sun, there existed the possibility that comet's remains would follow a slightly different orbit. To make sure he was covered, Weaver photographed two separate comet positions, stacking several exposures together.

"The images have been combined so that features not at the same place in the various images are suppressed. Any comet fragments would show up more clearly in this composite, though stars still show up as faint streaks", writes Zolt Lavay, author of the ISONblog at the Hubble site.

Comet ISON photographed at a second location. Again, nothing detected. Credit: NASA/ESA

Composite photo of one of two Comet ISON locations photographed by the Hubble Space Telescope. No trace of the comet is visible. Credit: NASA/ESA

Again, nothing shows up in these either. While no one can say that ISON has completely disappeared, we now know that at the very least it's broken into pieces too small for even Hubble to see. What was once a beautiful sight in binoculars has expanded into a vast cloud of gas and dust thinner than Ebenezer Scrooge's gruel.

Explore further: Incoming comet ISON appears intact to Hubble

add to favorites email to friend print save as pdf

Related Stories

Incoming comet ISON appears intact to Hubble

Oct 17, 2013

(Phys.org) —A new image of the sunward plunging Comet ISON suggests that the comet is intact despite some predictions that the fragile icy nucleus might disintegrate as the Sun warms it. The comet will ...

SOHO shows new images of Comet ISON

Nov 27, 2013

As Comet ISON heads toward its closest approach to the sun—known as perihelion—on Nov. 28, 2013, scientists have been watching through many observatories to see if the comet has already broken up under ...

NASA begins search for what is left of Comet ISON

Dec 05, 2013

Just prior to its closest approach to the sun on November 28, Comet ISON went through a major heating event, and likely suffered a major disruption. At this time, scientists are not sure how much of the comet ...

MicroObservatory catches comet ISON

Nov 18, 2013

Hopes are high for Comet ISON, which has the potential to become the most spectacular comet seen in years. ISON is speeding through the inner solar system at about 120,000 miles per hour, on its way to a ...

Comet ISON unfolds its wings

Nov 19, 2013

(Phys.org) —One or more fragments may have detached from comet ISON in the past days, as two wing-shaped features in the comet's atmosphere suggest. Scientists from the Max Planck Institute for Solar System ...

Recommended for you

Caterpillar comet poses for pictures en route to Mars

21 hours ago

Now that's pure gorgeous. As Comet C/2013 A1 Siding Spring sidles towards its October 19th encounter with Mars, it's passing a trio of sumptuous deep sky objects near the south celestial pole this week. ...

Hoisting a telescope with helium

22 hours ago

Many a child has forgotten to hold tight to the string of a helium balloon only to have it escape and rise until it disappeared in the glare of the sun. Helium balloons want to rise, but launching a balloon ...

User comments : 0