Today’s Astronomy Picture of the Day features Comet 2013-x1 (PanSTARRS) passing “close” to the Helix Nebula (New General Catalog 7293) in the constellation Aquarius. Actually, the comet is a foreground object composed of left over material from the solar system’s formation and the Helix nebula is 695 light years distant, not so close after all. The Helix is a “Planetary Nebula”, the short-duration end-state for sun-like stars where the expanding outer envelope of hydrogen gas leftover from the star’s final, end-state evolutionary stages continues to expand, excited to shine by the hot white-dwarf star at its center, an object that used to be the star’s thermonuclear core. In a case of astronomical serendipity, the two objects are visible within the same field of view, one representing new beginnings and the other, an ending, life and death, both in the same field of view.
As of today, Comet 2013-x1, discovered by Hawaii’s PanSTARRS 1 telescope on 4 December, 2013, is at magnitude 11 and 222 million kilometers from earth or 1.5 x the earth-sun distance and continues to recede. Both objects are faintly visible in binoculars now, low in the south during the pre-dawn hours with dark skies necessary to actually see them. Although the nebula has a visible magnitude of 7.6, only 1.6 magnitudes below the naked eye threshold, that light is spread out over an area equivalent to the full moon. A wide-field telescope would be the instrument of choice to observe both objects favorably.
Imagination is more important than knowledge
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