APOD: Perseids from Perseus (2020 Aug 10)

[APOD Robot]

Perseids from Perseus

Explanation: Where are all these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks tomorrow night is known as the Perseids -- the meteors all appear to came from a radiant toward Perseus. In terms of parent body, though, the sand-sized debris that makes up the Perseids meteors come from Comet Swift-Tuttle. The comet follows a well-defined orbit around our Sun, and the part of the orbit that approaches Earth is superposed in front of the Perseus. Therefore, when Earth crosses this orbit, the radiant point of falling debris appears in Perseus. Featured here, a composite image taken over eight nights and containing over 400 meteors from last August's Perseids meteor shower shows many bright meteors that streaked over Kolonica Observatory in Slovakia. This year's Perseids holds promise to be one of the best meteor showers of the year.

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[Ann]

Nice picture, nice Perseids and nice portrait of the Milky Way!

I have labeled some of the stars and nebulas:

This is what the numbers mean:

1) Betelgeuse and the Lambda Orionis Nebula.

2) The Pleiades and the California Nebula.

3) The Heart and Soul Nebulas (I think).

4) The North America Nebula and Deneb.

5) Vega.

6) Altair. (I know, that number 6 looks like an 8.)

7) Zeta Ophiuchi with its nebula.

Ann

[orin stepanek]

What can I say but, "Incomin!"

[neufer]

Incomin!

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<<Comet Swift–Tuttle is a large [i.e., comet nucleus 26 km in diameter] periodic comet that is in a 1:11 orbital resonance with Jupiter. It fits the classical definition of a Halley-type comet with a period between 20 and 200 years. It was independently discovered by Lewis Swift on July 16, 1862 and by Horace Parnell Tuttle on July 19, 1862. After the 1862 observations it was thought that the comet would return between 1979 and 1983, but it didn't show up. However, it had been suggested in 1902 that this was the same comet as that observed by Ignatius Kegler on July 3, 1737, and on this basis Brian Marsden calculated that it would return only in 1992, which in fact it did.

Chinese records indicate that, in 188, the comet reached apparent magnitude 0.1. Observation was also recorded in 69 BC, and it was probably visible to the naked eye in 322 BC. In the discovery year of 1862, the comet was as bright as Polaris. The comet made a return appearance in 1992, when it was rediscovered by Japanese astronomer Tsuruhiko Kiuchi and became visible with binoculars. In 2126 it will be a bright naked-eye comet reaching about apparent magnitude 0.7.

The comet's perihelion is just under that of Earth, while its aphelion is just over that of Pluto. An unusual aspect of its orbit is that it was recently captured into a 1:11 orbital resonance with Jupiter; it completes one orbit for every 11 of Jupiter. It was the first comet in a retrograde orbit to be found in a resonance. In principle this would mean that its proper long-term average period would be 130.48 years, as it librates about the resonance. Over the short term, between epochs 1737–2126 the orbital period varies between 128 and 136 years. However, it only entered this resonance about 1000 years ago, and will probably exit the resonance in several thousand years.>>

[Petr H.]

A rarity with this image: One fireball on 3rd APOD



I have just been pointed out on interesting APOD rarity. Today's APOD also contains bright and memorable fireball from 2018 Perseid peak, so same fireball was published and presented as APOD 3 different ways through last 2 years. Extremely bright fireball flew before local midnight of 12th August, 2018, exactly in 21:55:07,67 UTC, which surprised all of dozens of observers in and around the Kolonica Observatory. The fireball was so bright that even the nightscape around got brighter like under fainter moonlit and its light trail was visible for more than one hour after the fireball appeared in the sky! The mosaic shows the most amazing moments of the phenomenon – the firebal itself and development of the trail each next 1 minute. In fact, after an hour the remnants of the trail were larger than 80 degrees. More: https://www.astronom.cz/horalek/?p=4182

https://apod.nasa.gov/apod/ap180817.html
https://apod.nasa.gov/apod/ap190812.html
https://apod.nasa.gov/apod/ap200810.html

See video:

[RJN]

An oversight has been corrected. On the main NASA APOD, the phrase "last August's" has now been changed to "2018 August's". We apologize for the error. - RJN