APOD: Twisting with NGC 3718 (2013 Aug 03)

[APOD Robot]

Twisting with NGC 3718

Explanation: A careful look at this colorful cosmic snapshot reveals a surprising number of galaxies both near and far toward the constellation Ursa Major. The most striking is NGC 3718, the warped spiral galaxy near picture center. NGC 3718's spiral arms look twisted and extended, mottled with young blue star clusters. Drawn out dust lanes obscure its yellowish central regions. A mere 150 thousand light-years to the right is another large spiral galaxy, NGC 3729. The two are likely interacting gravitationally, accounting for the peculiar appearance of NGC 3718. While this galaxy pair lies about 52 million light-years away, the remarkable Hickson Group 56 can also be seen clustered above NGC 3718, near the top of the frame. Hickson Group 56 consists of five interacting galaxies and lies over 400 million light-years away. This picture was chosen as the overall winner in the 2013 David Malin Astrophotography Competition.

<< Previous APOD

This Day in APOD

Next APOD >>

[/b]

[Ann]

NGC 3718 is a fascinating galaxy, and I was glad to see a portrait of it become an APOD. It is of course a bonus that the Hickson Group 56 is located so favorably along the line of sight of NGC 3718.

As for NGC 3718 itself, note the diaphanous nature of much of the disk. Two slightly more substantial spiral or tidal arms point "up" and "down". It is almost as if the galaxy wore a see-through "dress" around its "legs".

The yellow bulge is large and the twisting dust lane is finely detailed. Most of the rest of the galaxy is "soft", without features. An amorphous blue "ring" encircles the yellow bulge. But there is star formation at the end of the lower arm and along much of the top arm.

The morphology of NGC 3729 is quite different. There is a bright blue ring with star formation encircling the yellow bulge, but outside the ring, the disk becomes smooth and diffuse.

What I would have liked to see more of in the caption is some additional information about the picture itself. When I clicked on the link about the David Malin Astrophotography Competition, I came to a page which showed me a smaller version of today's APOD.

I did note one thing on the David Malin Astrophotgraphy page (or the universe@CSIRO page). The version of Martin Pugh's picture looks better color-balanced there than it does here. Here, the bulges of NGC 3718 and NGC 3729 are unnaturally orange, whereas they look more naturally yellow on the universe@CSIRO page. On that page, the color of the blue ring around the bulge of NGC 3718 is also quite muted, which seems realistic. On the other hand, there are some fascinating red details in the disk of NGC 3729 that seem to be missing in today's APOD.

So would it be possible to include some information about Martin Pugh's image other than that which is provided on the universe@CSIRO page?

Ann

[Ann]

A larger version of Martin Pugh's picture, with the proper color balance, is here.

Ann

[geckzilla]

A larger version of Martin Pugh's picture, with the proper color balance, is here.

Ann

Seems to be a different file. When you click the small APOD and the large one is brought up, that's the original that the photographer supplied. It's possible the APOD version is a more recent revision.

[Boomer12k]

"Come on, BAAAABYYYY....Let's Do the TWIST!!!!"....OUUUUU!!!!

Awesome galaxy...I wonder if one way to get a spiral galaxy...is the merger of two Ellipticals...that begin to twist around, and fly apart...and as they come together gather more dust, and form into a spiral....after they calm down, of course.

Some seem to be older Globular Clusters, that draw in gas and dust and then form a ring, or spiral also...

Thank you, Ann for your observations!

:---[===] *

[nstahl]

Great picture! I can see how it could win that contest.

[henrystar]

Surely this should be called the Paragraph Nebula? That is, § ? Of course we are seeing it from the wrong side!

[owlice]

§ is a section mark! ¶ is for paragraph.

[quigley]

There appear to be several ring-like structures staggered around the central core? Are they indeed rings and why are they there?

[neufer]

Surely this should be called the Paragraph Nebula? That is, § ?
Of course we are seeing it from the wrong side!

§ is a section mark! ¶ is for paragraph.

<<The section sign (§, Unicode U+00A7, HTML entity &sect;) is a typographical character used mainly to refer to a particular section of a document, such as a legal code. It is also called "double S", "hurricane", "sectional symbol", "the legal doughnut", signum sectiōnis. It is frequently used along with the pilcrow (¶), or paragraph sign. The likely origin of the section sign is the digraph formed by the combination of two S'es (from the Latin signum sectionis). When duplicated, as §§, it is read as the plural "sections" (§§ 13–21), much as "pp." (pages) is the plural of "p." (short for the Latin pagina).

The section symbol is used by horse racing rating service Timeform to denote a horse is unreliable.
Such a horse is usually referred to as a "squiggle horse".>>

<<The pilcrow (¶), also called the paragraph mark, paragraph sign, paraph, alinea (Latin: a lineā, "off the line"), or blind P, is a typographical character for individual paragraphs. It is present in Unicode as U+00B6 ¶ pilcrow sign. According to the OED, the word pilcrow "apparently" originated in English as an unattested version of the French pelagraphe, a corruption of paragraph; the earliest reference is c.1440.

In form, the pilcrow is understood to have originated as a letter C, for capitulum, "chapter" in Latin. This C was the paraph symbol that replaced in the function of marking off paragraphs the Greek-style paragraphos, and other symbols including the section sign. Moreover, the paraph also could be marked with a full-height sign similar to ¢ (cents) or with a double slash, originally symbols indicating a note from the scribe to the rubricator. The Oxford Universal Dictionary says "pilcrow" may be from "pulled [plucked] crow," based on its appearance.

The pilcrow can be used as an indent for separate paragraphs or to designate a new paragraph in one long piece of copy, as Eric Gill did in his 1930s book, An Essay on Typography. The pilcrow was a type of rubrication used in the Middle Ages to mark a new train of thought, before the convention of visually discrete paragraphs was commonplace.>>

[Beyond]

HA-HA-HA-HA-HA-HA-HA!!

[ta152h0]

should be called Fokker's Propeller galaxy

[neufer]

---

• should be called Fokker's Propeller galaxy

• Not to be confused with Fokker's Propeller nebula

---

[foobar]

Surely this should be called the Paragraph Nebula? That is, § ?
Of course we are seeing it from the wrong side!

§ is a section mark! ¶ is for paragraph.

<<The section sign (§, Unicode U+00A7, HTML entity &sect;) is a typographical character used mainly to refer to a particular section of a document, such as a legal code. It is also called "double S", "hurricane", "sectional symbol", "the legal doughnut", signum sectiōnis. It is frequently used along with the pilcrow (¶), or paragraph sign. The likely origin of the section sign is the digraph formed by the combination of two S'es (from the Latin signum sectionis). When duplicated, as §§, it is read as the plural "sections" (§§ 13–21), much as "pp." (pages) is the plural of "p." (short for the Latin pagina).

The section symbol is used by horse racing rating service Timeform to denote a horse is unreliable.
Such a horse is usually referred to as a "squiggle horse".>>

<<The pilcrow (¶), also called the paragraph mark, paragraph sign, paraph, alinea (Latin: a lineā, "off the line"), or blind P, is a typographical character for individual paragraphs. It is present in Unicode as U+00B6 ¶ pilcrow sign. According to the OED, the word pilcrow "apparently" originated in English as an unattested version of the French pelagraphe, a corruption of paragraph; the earliest reference is c.1440.

In form, the pilcrow is understood to have originated as a letter C, for capitulum, "chapter" in Latin. This C was the paraph symbol that replaced in the function of marking off paragraphs the Greek-style paragraphos, and other symbols including the section sign. Moreover, the paraph also could be marked with a full-height sign similar to ¢ (cents) or with a double slash, originally symbols indicating a note from the scribe to the rubricator. The Oxford Universal Dictionary says "pilcrow" may be from "pulled [plucked] crow," based on its appearance.

The pilcrow can be used as an indent for separate paragraphs or to designate a new paragraph in one long piece of copy, as Eric Gill did in his 1930s book, An Essay on Typography. The pilcrow was a type of rubrication used in the Middle Ages to mark a new train of thought, before the convention of visually discrete paragraphs was commonplace.>>

Thank God I asked the question! Now we all know, and can never forget!

[geckzilla]

You got neufered. It's better than getting neutered.

[neufer]

You got neufered. It's better than getting neutered.

I was just trying to fix things (like Bertrand Zobrist would have).

[Beyond]

Once again i just have to say...HA-HA-HA-HA-HA-HA-HA!!

[ta152h0]

being neutered is permanent, being neufored not so much

[Beyond]

There's an Art to being neufer. Not just anyone can do it, thank God including himself, sometimes.

[PhilT]

My question is 'why doesn't the other galaxy appear to be distorted ?" - NGC3718 is not apparently in direct line of the other galaxies spin axis so ???

Anybody who can explain ?

[neufer]

My question is 'why doesn't the other galaxy appear to be distorted ?"

• 1) Our perspective on NGC 3718 makes it easier to see the distortion than in the case of NGC 3729
  2) They are oscillating distortions that is observed at near peak amplitude for NGC 3718 but near null amplitude for NGC 3729
  3) NGC 3729 is both more massive & more compact than NGC 3718 so it was less disturbed in the first place
  4) Something else.

[geckzilla]

4) Aliens. [Picture of Ancient Aliens dude]

It's always aliens.

[Ron-Astro Pharmacist]

I think you got the "P" part right but I think it should be the Potato Chip galaxy. But of course I would - being from Idaho.

[Anthony Barreiro]

Such a beautiful picture! It really does look like this galaxy is doing the dance of Salome behind a veil of young blue stars. At 150,000 light years, these two galaxies are closer than the Magellanic clouds are to the Milky Way!

[neufer]

It really does look like this galaxy is doing the dance
of Salome behind a veil of young blue stars.

BOLONEY