Hubble’s ISON Update

Hubble's look at ISON.  Click for larger. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
Hubble’s look at ISON. Click for larger. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

The impending ISON breakup that seems to be predicted on certain Internet sites is a FAIL so far. Not to say it won’t happen, just so far it hasn’t happened.

Comet ISON has brightened by a half a magnitude since Monday’s post, it has broken the mag 9 mark and is now 8.99 according to Stellarium and The Sky program I use. I am going to try and get a small scope on it this weekend. If I have REALLY good weather I might try using the big scope I think it is high enough to see. I have a problem in that direction due to trees, normally not too much of an issue because I can wait, but this is a close call with sunrise.

From Hubblesite:

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 pass closest to the Sun on November 28.

In this NASA Hubble Space Telescope image taken on October 9, the comet’s solid nucleus is unresolved because it is so small. If the nucleus broke apart then Hubble would have likely seen evidence for multiple fragments.

Moreover, the coma or head surrounding the comet’s nucleus is symmetric and smooth. This would probably not be the case if clusters of smaller fragments were flying along. What’s more, a polar jet of dust first seen in Hubble images taken in April is no longer visible and may have turned off.

This color composite image was assembled using two filters. The comet’s coma appears cyan, a greenish-blue color due to gas, while the tail is reddish due to dust streaming off the nucleus. The tail forms as dust particles are pushed away from the nucleus by the pressure of sunlight. The comet was inside Mars’ orbit and 177 million miles from Earth when photographed. Comet ISON is predicted to make its closest approach to Earth on December 26, at a distance of 39.9 million miles.

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