Comet 96P/Machholz Visible in SOHO Images
July 13, 2012 1 Comment
Updated (at 3 pm Tucson time on July 17).
Every ~5.3 years, comet 96P/Machholz makes a close and personal swing around the Sun. At a distance of 0.12 AU, comet Machholz comes within 11 million miles (18 million km). That is 8 times closer to the Sun than the Earth and even 2.5 times closer than the innermost planet Mercury.
Though the comet can become very bright at perihelion, its close proximity to the Sun makes it all but impossible to observe at that time. Luckily we have a number of spacecraft observing the Sun which can also be used to observe the comet. One such spacecraft, the joint ESA/NASA Solar and Heliospheric Observatory (SOHO) is currently picking up the comet. The image below is the latest image from the LASCO instruments on the spacecraft. [Update: 96P has now moved out of the SOHO LASCO field-of-view.
As of 10 am (Tucson time) on the 13th, the comet is visible to the lower right of the Sun. A short tail is also visible trailing away from the Sun. As of 10 am (Tucson time) on the 14th, the comet is visible just to the upper right of the center obscuration. As of 10 am (Tucson time) on the 15th, the comet is visible halfway between the center and the top of the image. As of 8 am (Tucson time) on the 16th, 96P is visible near the edge of the field at the 11 o’clock position. Since the comet is about as close to the Sun as it gets, it is also visible in the higher resolution LASCO C2 field. A real-time C2 image is located below under the C3 image. In the C2 image the comet can be seen near the upper right corner though it will move out of the field in a few hours. The comet is no longer visible in the C2 field.] Additional SOHO images can be found here.
Perihelion occurred on July 14.78 UT (or roughly 11:40 am Tucson time on the 14th, that’s 11:40 am PDT, 12:40 pm MDT, 1:40 pm CDT, 2:40 pm EDT). By the end of July, the comet will be visible in the evening sky as a faint and difficult 9-10th magnitude object for telescope observers.