APOD: NGC 1566: The Spanish Dancer Spiral... (2022 Jan 14)

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APOD: NGC 1566: The Spanish Dancer Spiral... (2022 Jan 14)

Post by APOD Robot » Fri Jan 14, 2022 5:11 am

Image NGC 1566: The Spanish Dancer Spiral Galaxy

Explanation: An island universe of billions of stars, NGC 1566 lies about 60 million light-years away in the southern constellation Dorado. Popularly known as the Spanish Dancer galaxy, it's seen face-on from our Milky Way perspective. A gorgeous grand design spiral, this galaxy's two graceful spiral arms span over 100,000 light-years, traced by bright blue star clusters, pinkish starforming regions, and swirling cosmic dust lanes. NGC 1566's flaring center makes the spiral one of the closest and brightest Seyfert galaxies. It likely houses a central supermassive black hole wreaking havoc on surrounding stars, gas, and dust. In this sharp southern galaxy portrait, the spiky stars lie well within the Milky Way.

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Ann
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Re: APOD: NGC 1566: The Spanish Dancer Spiral... (2022 Jan 14)

Post by Ann » Fri Jan 14, 2022 6:36 am

I'm very glad to see Mark Hanson and Mike Selby get an APOD! They are great astrophotographers! :D

NGC 1566 is, in my opinion, the best example in the relatively nearby sky of a "perfect" spiral. The winner in that category is often said to be M74, but I think that NGC 1566 is better.


As you can see, the arms of NGC 1566 are much more "dramatic" than the arms of M74. The inner arms of NGC 1566 are bright, extremely symmetrical and peppered with pink nebulas and star formation. M74, by contrast, is known as the "Ghost galaxy", because it is so hard to spot in an amateur telescope due to the faintness of its arms and disk.

Mark Hanson and Mike Selby has not got access to a really professional telescope. Therefore, I can't resist showing you an "official" Hubble image of M74, and a picture of NGC 1566 based on Hubble Legacy Archive:

NGC 1566 Andrealuna Pizzetti Hubble Legacy.png
NGC 1566. Andrealuna Pizzetti/Hubble Legacy Archive

The "dramatic" nature of the arms of NGC 1566 is obvious, as is the "soft" nature of the arms of M74. The arms of NGC 1566 stand out starkly because of the brilliant star formation along the length of the inner arms (and the apparent "emptiness" just outside them), whereas in M74 the arms stand out much more weakly from the disk.

Another difference is that NGC 1566 is a barred galaxy. NGC 1566 does not have a long or strong bar, but you can clearly see that NGC 1566 appears to have a "skewed" center. Mark Hanson and Mike Selby's image shows you that NGC 1566 does not have a "filled", perfectly "round" outer disk, but that its outer arms give it a "dancing" shape. 💃 M74, by contrast, is "all round".

It is interesting to compare NGC 1566 with NGC 1365:


The shape of NGC 1365 is obviously even more dramatic than the shape of NGC 1566. NGC 1365 seems to be made up exclusively of a long bar and two long arms that start at impossible angles at the ends of the bar. I'd say that NGC 1566 is "intermediate" between M74 and NGC 1365! :D

Ann
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Re: APOD: NGC 1566: The Spanish Dancer Spiral... (2022 Jan 14)

Post by VictorBorun » Fri Jan 14, 2022 10:30 am

Ann wrote:
Fri Jan 14, 2022 6:36 am
Mark Hanson and Mike Selby's image shows you that NGC 1566 does not have a "filled", perfectly "round" outer disk, but that its outer arms give it a "dancing" shape. 💃 M74, by contrast, is "all round".
The galactic plane is inclined at an angle of 31°±7° to the line of sight to the Earth

I think a galaxy is a stirring dancer if its arms are far from making a circle, or an ellipsis in the image for us on Earth.
If we want such a galaxy we have to use a high speed event spreading from the core in two opposite directions in the plane of the disk. Then the rotation of the disk could not quite smear the two radial jets to a ring.

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Re: APOD: NGC 1566: The Spanish Dancer Spiral... (2022 Jan 14)

Post by orin stepanek » Fri Jan 14, 2022 1:16 pm

NGC1566LRGBHa-Hanson-SelbyFinal1024.jpg
The Spanish Dancer is indeed a beautiful galaxy among a lot of
beautiful galaxies! My favorite; of course ic the Milky Way! :mrgreen:
Kudos to Hanson-Selby for a wonderful photo!
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Re: APOD: NGC 1566: The Spanish Dancer Spiral... (2022 Jan 14)

Post by neufer » Fri Jan 14, 2022 2:34 pm

https://en.wikipedia.org/wiki/Festina_lente wrote: <<Festina lente is a classical adage and oxymoron meaning "make haste slowly" (sometimes rendered in English as "more haste, less speed"). It has been adopted as a motto numerous times, particularly by the emperors Augustus and Titus, the Medicis and the Onslows. The original form of the saying, σπεῦδε βραδέως speũde bradéōs, is Classical Greek, of which festina lente is the Latin translation. The words σπεῦδε and festina are second-person-singular present active imperatives, meaning "make haste", while βραδέως and lente are adverbs, meaning "slowly".

The meaning of the phrase is that activities should be performed with a proper balance of urgency and diligence. If tasks are rushed too quickly then mistakes are made and good long-term results are not achieved. In physics, the name "Festina Lente Limit" has been applied to the Strong Confinement Limit, which is a mode of an atom laser in which the frequency of emission of the Bose–Einstein condensate is less than the confinement frequency of the trap.

The Roman historian Suetonius, in De vita Caesarum, tells that Augustus deplored rashness in a military commander, thus "σπεῦδε βραδέως" was one of his favourite sayings. Certain gold coins minted for Augustus bore images of a crab and a butterfly to attempt an emblem for the adage. Other such visualizations include a hare in a snail shell; a chameleon with a fish; a diamond ring entwined with foliage; and perhaps most recognizably, a dolphin entwined around an anchor. Cosimo I de' Medici, Grand Duke of Tuscany took festina lente as his motto and illustrated it with a sail-backed tortoise.

The Renaissance printer Aldus Manutius adopted the symbol of the dolphin and anchor as his printer's mark. Erasmus (whose books were published by Manutius) featured the phrase in his Adagia and used it to compliment his printer: "Aldus, making haste slowly, has acquired as much gold as he has reputation, and richly deserves both." Manutius showed Erasmus a Roman silver coin, given to him by Cardinal Bembo, which bore the dolphin-and-anchor symbol on the reverse side. The adage was popular in the Renaissance era and Shakespeare alluded to it repeatedly. In Love's Labour's Lost, he copied the crab and butterfly imagery with the characters Moth and Armado. Jean de la Fontaine alluded to the motto in his famous fable of "The Hare and the Tortoise" (Fables, 1668–94), writing that the tortoise "with a prudent wisdom hastens slowly".

The adage was a favourite of the influential judge, Sir Matthew Hale, who was naturally a quick man; yet, by much practice on himself, he subdued that to such a degree, that he would never run suddenly into any conclusion concerning any matter of importance. Festina Lente was his beloved motto, which he ordered to be engraved on the head of his staff, and was often heard to say that be had observed many witty men run into great errors, because they did not give themselves time to think... — Bishop Burnet, The Life and Death of Sir Matthew Hale>>
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Re: APOD: NGC 1566: The Spanish Dancer Spiral... (2022 Jan 14)

Post by Fred the Cat » Fri Jan 14, 2022 10:29 pm

Super spiral galaxies put a new spin how fast is too much to spin out.

Life in a super spiral could be like playing - spin the potato. :wink:
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