There’s no telling whether anyone will yet see the “phoenix comet” that survived a close encounter with the Sun last week and continued to keep it together until it exited the coronagraph on the orbiting Solar and Heliospheric Observatory (SOHO).
The last we heard, SOHO-2875, now formally named C/2015 D1 (SOHO), still glowed around magnitude +4 on Feb. 21.
Now the hunt is on to see if enough of the comet remains after its perilous journey to make an appearance in evening twilight. After many position measurements from photos taken by SOHO, an orbit has been calculated that was just published today. Using those numbers, I made a map showing the comet’s nightly progress as it travels up from the western horizon not far from Venus and Mars through the constellations Pisces and Andromeda over the next couple weeks.
Don’t expect to see it tonight. It’s likely no brighter than the naked eye limit (magnitude +6) and swamped in the glow of twilight very low in the western sky. Still, by good fortune, it just happens to hover very close to the star Gamma in Pisces about 5° above the horizon near the end of dusk.Those with crystal clear skies and an open view to the west should give it a try.
The situation soon improves as SOHO’s northward movement carries it higher into a darker sky. It’s uncertain if the comet is a tight, dense ball or a ballooning bag of dust. Until the first observations come in, we won’t know how the comet’s fairing. Also keep in mind that the orbit is preliminary, meaning C/2015 D1 may not exactly follow the path shown. Do sweeps around the positions, moving left and right and up and down from each nightly spot.
I’m as eager as you to see our new visitor.