News from comet ISON

Comet C2012/S1 ISON: the brightest comet in the XXI century (so far) followed by GLORIA.

Comet ISON at dawn on November 21st (6:20 UT). The image was taken from the Teide Observatory (Instituto de Astrofísica de Canarias) with a digital camera (Canon 5D-MII, 85mm lens) and an exposure time of about 6 seconds. The brightest object in the image is the planet Mercury, while at the bottom center, just above the sea of ​​clouds, the peaks of the Gran Canaria island are visible. Credits: J.C. Casado, iac.es.

On its way to the Sun, comet C2012/S1 ISON will continue to brighten, but it will also get harder and harder to see since it will be close to the Sun in the sky. Right now the comet is close to the eastern horizon before dawn. See the 3-D model.

View our Flickr album

View the timelapse from the Teide observatory on YouTube:
November 21st, 2013
November 22nd, 2013

November Blog

Nov. 1. The rate of increase in the brightness of Comet ISON is much slower than predicted. Moreover, at this stage it is not even clear if it will reach the perihelion passage.

Nov. 10. Comet ISON starts displaying its ion tail in the anti-solar direction.

The comet ISON as seen on November 11th, 2013 by the GLORIA CATA500 telescope at Cerro Tololo, Chile.

Nov. 13. Comet ISON undergoes an outburst which resulted in the production of a large amount of gas (according to IAA-CSIC with the 30m Pico Veleta radio telescope). The corresponding increase in optical brightness is significant!

A stack of 13x10s unfiltered images taken by BOOTES-2/TELMA + COLORES on Nov. 15, 2013.

Nov. 15. The outburst phase of Comet ISON has concluded, with a total brightness change of 3 magnitudes (factor of ~15) in 3 days. Now it can be observed with the naked eye!

Nov. 18. It is unclear what has happened to Comet ISON. Hermann Boehnhardt (Max-Planck Institute for Solar System Research, Katlenburg-Lindau, Germany) found an early warning sign that its nucleus has possibly undergone splitting into 2 or more sub-nuclei. This is not yet confirmed and other scientists think that the comet has only activated its surface, regaining its original level of activity.

Nov. 22. The comet is under “strict observation” from the Teide observatory (Canary Island).


Have a look to the Flickr album and the timelapse on YouTube:
November 21st, 2013,
November 22nd, 2013.

On November 28th, the comet will make its nearest approach (the so-called perihelion passage) to the Sun, at 1.1 million km. Then, the comet will take a right angle turn in the sky, swinging around the Sun and blazing northward in the evening sky. Close to perihelion it may be possible to see the comet in the daytime with the naked eye. This ‘dirty snowball’  is special because it is a “newcomer” from the very distant Oort cloud of comets, coming very close to the Sun for the first time.

In the coming nights, GLORIA will continue observing Comet ISON with all suitable telescopes in imaging mode. Spectroscopic observations are expected to be conducted with the COLORES spectrograph attached to BOOTES-2/TELMA.

The planned strategy is to convolve the images by applying a Laplace filter or a rotational gradient filter to sharpen the images, in order to confirm the possible nucleus fragmentation as result of the intense gravitational forces. Stay tuned!

Useful links

  1. The comet orbit by SolarSystemScope.
  2. Comet live tracker
  3. Comet news, facts and information.
  4. Finder chart and apparent brightness data also posted here.