Comet 62P Tsuchinshan will be at perihelion on Christmas Day.
This space view, from 35° north of the ecliptic plane, shows the path of the comet in 2023 and 2024, with stalks to the plane at 1-month intervals, and sightlines from Earth to the comet at 2023 December 25 and 2024 March 20. Grid lines on the ecliptic plane are 1 AU (astronomical unit, Sun-Earth distance, about 150 million km or 93 million miles) apart. Earth is exaggerated 500 times in size, the Sun only 5 times. See the end note about enlarging illustrations.
Perihelion is the innermost point of an orbit around hêlios, the Sun. But this comet, though it will be well placed in our sky, and is a kind of old returning friend, will be a target for telescopes and binoculars, not for the naked eye.
And here is the comet’s path across Leo in December and January. Stars are shown down to magnitude 8. The comet will be dimmer than many not shown..
The Purple Mountain Observatory is near Nanjing in central China. The Chinese name of the mountain and observatory was given in the Wade-Giles transliteration as Tsuchinshan, but in the Pinyin system now used it is Zijinshan – remarkably different! Two comets were discovered there on 1965 Jan. 1 and 11. Comets can be named for one, two, or even three independent discoverers, but, if discovered by a team at an institution, get the name of that institution. These two comets were the first to be named in that collective way. And by an earlier rule for periodic comets, they were Tsuchinshan 1 and 2; now they are 62P/Tsuchinshan and 60P/Tsuchinshan, the numerals being the order in which they were established as periodic comets.
They were discovered when both happened to be near perihelion; and their orbits have roughly similar size (period near 6.7 years), shape (eccentricity near 0.5), and perihelion distance (near 1.5 AU), but are oriented in different directions; so the two were not close together in space when discovered or at other times. Both were featured in several years of the Astronomical Calendar. 62P was observed during its returns of 1971, 1978, 1985, 1991, 2004, 2018, apparently missed in 2011.
In 2023, it arrived within 1 AU of Earth on Oct. 12, and ascended northward through the ecliptic plane on Oct. 17.
On Dec. 25, when it passes through perihelion, it will be 1.27 AU from the Sun, and 0.53 AU from Earth. It will be in the midnight sky: at elongation (angular distance from the Sun) of 110° – not straight outward from the Sun as at opposition but slightly “rightward” (westward) into the morning sky. Its magnitude should be 9.6. This, in the logarithmic scale used in astronomy, means about 4,000 times less bright than the naked-eye limit of about magnitude 6.
(Magnitude predictions are notoriously unreliable for comets, because of their “behavior” as they approach the Sun and the ices of the tiny solid nucleus evaporate, releasing dust and gas in irregular amounts and directions to form the cloud-like head and the tail, so that there can be bright outbursts, or the nucleus may be left bare, like an asteroid, or the comet may break up and disappear.)
62P may brighten by a fraction of a magnitude around the time when it is nearest (0.495 AU) to Earth, Jan. 29. We will pass it at opposition on March 20, but by then it will be 0.6 AU from us and probably down to magnitude 11.
A purple mountain that I once saw – in Turkey. I haven’t found anyone’ estimate for the size of this comet’s nucleus, but a typical width is 6 miles
__________
This weblog maintains its right to be about astronomy or anything under the sun.
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” or “Open image in new tab”, 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.
Sometimes I make improvements or corrections to a post after publishing it. If you click on the title, rather than on ‘Read more’, I think you are sure to see the latest version. Or you can click ‘Refresh’ to get the latest version.
it is a good looking picture!
There is a monument at the summit of Pikes Peak where Bates wrote the poem which became the US national anthem. You can stand in that spot and observe what she wrote during wheat harvest time.
Katherine Lee Bates was a native of my town, Falmouth MA, here on Cape Cod.
In front of the town’s main library there is a very nice statue of her, cast as a young woman in her early 20’s gazing out from on top of Pike’s Peak.
————
Guy, I have wondered, in your drawings of planetoid orbits relative to the ecliptic plane with a superimposed 1 AU grid, are the stalks indicating orbital inclinations above or below the ecliptic plane drawn to the same AU scale?
I can tell from the accompanying illustration of the sky around Leo that, at the solstice, the comet seems to be about 8 degrees “above” the ecliptic plane.
I recognize that crosswise ticks on the stalks would make the orbital drawing a bit “noisy”.
Kenneth, in my 3-D diagrams every point is projected angularly as seen from the viewpoint. So the points in a stalk, such as the two ends of it, are separated as they would be in a photograph taken from the viewpoint. The same kind of projection determines, for every point in the grid, its position on the “paper” (if the diagram were to be printed.
The stalks are not spatially very long because the comet stays fairly close to the ecliptic. In some diagrams in the Astronomical Companion stalks have to be long, for instance from a northerly star to the equatorial plane, and then I make my program calculate the eye position for several points in the stalk, so that it curves.
In the chart, the comet appears 8 degrees north of the ecliptic because that is the angular separation as seen from Earth.
I Hope I’ve understood your question and answered i!
The patriotic song “America the Beautiful” starts with this quatrain:
O beautiful for spacious skies,
For amber waves of grain,
For purple mountain majesties
Above the fruited plain!
In 1893 Katharine Lee Bates, an English professor at Wellesley College, took a train trip to teach at Colorado College. Looking out across the plains from atop Pike’s Peak, Bates was inspired to write “America. A Poem for July 4.” The poem, retitled, was later set to music by the New Jersey Episcopal church organist and choirmaster Samuel A. Ward.
The United States did not have an official national anthem until 1931. Many people wanted “America the Beautiful” to be our national anthem, and there have been repeated campaigns to give it official status alongside or in lieu of “The Star Spangled Banner.” “America the Beautiful” is easier to sing and (to my ear) much more sonorous than “The Star Spangled Banner.” “The Star Spangled Banner” glorifies war and slavery, while “America the Beautiful” uplifts Christian virtues, albeit from a 19th century white settler perspective.
You can make your christmas pudding purple if you put brandy on it and light it.
/Users/rickscheithauer/Desktop/Christmas_pudding_(Heston_from_Waitrose)_flaming.jpg