Here is the newly discovered bright comet in tomorrow’s pre-dawn sky.
See the end note about enlarging illustrations.
At the time and place of the picture it is 10° above the horizon. The arrows through the comet, planets, and Sun show their movement, relative to the starry background, over a week centered on this date.
I calculate the comet’s magnitude as 1.7, like some of the brightest stars; reports are that it may be about 4, still above the naked-eye limit of around 5. Its tail, drawn rather optimistically in the picture to show how it is pushed away from the Sun, may be one or two degrees long, depending on the instrument you use.
This comet was discovered on March 27 as a by-product of the program carried out by a space telescope with an acronym-friendly name, Wide-field Infrared Survey Explorer, yielding WISE, further embedded in NEOWISE, meaning not “newly wise” but that we are wise to look out for NEOs, “near-Earth objects,” some of which could impact Earth as the Tunguska object did.
In this space view, lines on the ecliptic plane are 1 astronomical unit (Earth-Sun distance) apart. Stalks from the comet’s path to the ecliptic plane are at the beginning of each month; Earth is shown at the beginning of each month, exaggerated 500 times in size; the Sun is exaggerated only 5 times. The red line is the sightline from Earth to the comet at July 10. The comet went through perihelion, only 0.29 of an a.u. from the Sun, on July 3.
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ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format. You may be able to enlarge them on your monitor. One way: right-click, and choose “View image,” then enlarge. Or choose “Copy image,” then put it on your desktop, then open it. On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers). Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways
Finally got a clear night, first in three weeks for me in NE England, on July 11-12. Checking the sky for noctilucent clouds at 00:15 UT, and BANG! Yes, there’s some weak NLC, but THAT’S THE COMET!!! Easily visible with no optical aid, and a gently curving tail I could follow without difficulty for at least 5 or 6 degrees (the greater length using averted vision; yes, that’s 5 degrees using direct vision in the strong twilight arch!).
I’m hopeless at estimating comet brightnesses, but as I followed it for the rest of the night after that, I estimated its coma was about magnitude +1.5. Checking online today suggests people who know what they’re doing with such things estimated it at mag. +1.6 around the same time, so I was quite pleased by that!
In the 7×50 binoculars, I could follow the tail – and there are two elements to it, though the straight (presumably gas) tail is definitely the fainter – for about 7 to 8 degrees, so continuing beyond the 7-degree binocular field.
What a treat! Best comet I’ve seen since Hale-Bopp back in ’97, as though it’s not quite in the same class, it’s a very fine object, easily-seen.
Quite a night all-told, in fact, as there was Jupiter and Saturn over to the low southwest, with the last quarter Moon rising to the southeast next to Mars simultaneously, followed by the ISS pass around 01:30 UT – looked to have peaked about magnitude -2.5 or so to me, compared with Jupiter – and finally Venus rising to the northeast just over a degree from Aldebaran shortly after that.
I managed to follow the comet without optical aid till about 02h UT – it was still ridiculously easy, albeit with averted vision by then – and then with the 7x50s for another half-hour or so, while only Capella remained visible of the nearby stars by that time. So, if you’ve had no luck spotting it as yet from suitable mid-northern sites, or if the weather’s been against you, do persevere, as from what I saw last night, it’s definitely worth it.
About an hour before sunrise this morning, 10 July, the comet was beautiful in 10×42 image-stabilized binoculars, with a bright nucleus and a prominent creamy-colored dust tail about 2 degrees long pointing straight up. At times I thought I saw a hint of bifurcation in the tail. Once I had found the comet with binoculars it was easily visible to the naked eye.
It’s a treat to see a comet here in light-polluted San Francisco.
Encouraged by my success seeing the comet from home during dawn yesterday morning, I got up at 3:30 am PDT this morning and walked up Bernal Hill for an open northeastern horizon. A few clouds, but none around the comet, and the sky was very transparent. Around 4:15, about 10 minutes after astronomical dawn, the comet was visible to the naked eye, and gorgeous through binoculars. Against the darker sky the tail was longer, slightly feathery, and it curved slightly to the east before fading out imperceptibly. I’m sure with more aperture I would have seen more tail. I was able to see the head of the comet through binoculars until 5:30, about half an hour before sunrise. There were a few other people on the hill also watching the comet. Nice to have some astronomical company for such a beautiful sight.
As viewed from the Blue Ridge Mountains in Virginia, it is the best comet in 10 years. Through 10×50 binoculars, the tail approaches two degrees in length and its coma glows a little brighter than magnitude 4. We looked 70 minutes before sunrise on July 9. Looking forward to see how it appears next Friday evening when it scoots under the bowl of the Big Dipper. You never know with these things!
What a great map! I am keen to see it but in England a westerly weather system has moved in,you might say after 4 months of solid rain over winter I’ve had a bellyful of rain!as the Carpenters sang;’rainy days get you down’!well so much for Boris’s beer gardens and outdoor activities!high pressure promised to move in from tomorrow.i had a go at the comet a few nights ago using my Viking 10×42 monocular scanning the northern horizon under and around Capella,no luck but it wasn’t second magnitude then.i think that the Holmes comet was my last bright comet, although I did see a dim one a few years back.i viewed the Holmes comet through a tiny pair of Tasco 6×16 binoculars and the naked eye and it had no tail like a huge Omega Centauri.