APOD: M100: A Grand Design Spiral Galaxy (2023 Apr 08)

[APOD Robot]

M100: A Grand Design Spiral Galaxy

Explanation: Majestic on a truly cosmic scale, M100 is appropriately known as a grand design spiral galaxy. It is a large galaxy of over 100 billion stars with well-defined spiral arms that is similar to our own Milky Way Galaxy. One of the brightest members of the Virgo Cluster of galaxies, M100 (alias NGC 4321) is 56 million light-years distant toward the constellation of Berenice's Hair (Coma Berenices). This Hubble Space Telescope image of M100 was taken with the Wide Field Camera 3 and accentuates bright blue star clusters and intricate winding dust lanes which are hallmarks of this class of galaxies. Studies of variable stars in M100 have played an important role in determining the size and age of the Universe.

<< Previous APOD

This Day in APOD

Next APOD >>

[Ann]

Hooray! One of my favorite galaxies is the subject of today's APOD.

M100: A Grand Design Spiral Galaxy Image Credit: NASA, ESA, Hubble; Processing: Judy Schmidt

---

I have a particularly soft spot for M100 for two reasons. First, because M100 was the galaxy that Hubble photographed back in December 1993 to show us its improved vision after it had been fitted with "glasses":

---

hubblesite wrote:

This comparison image of the core of the galaxy M100 shows the dramatic improvement in Hubble Space Telescope's view of the universe. The new image was taken with the second generation Wide Field and Planetary Camera (WFPC-2) which was installed during the STS-61 Hubble Servicing Mission. The picture beautifully demonstrates that the corrective optics incorporated within the WFPC-2 compensate fully for optical aberration in Hubble's primary mirror. The new camera will allow Hubble to probe the universe with unprecedented clarity and sensitivity, and to fulfill many of the most important scientific objectives for which the telescope was originally built.

The second reason why I love M100 is this picture from my trusted old Color Atlas of Galaxies by James D Wray, from 1988:

M100 with supernova SN 1979C from The Color Atlas of Galaxies.
The supernova is the bright blob at lower right.
Credit: James D. Wray.

I really apologize for the lousy picture, because I had to photograph the not very sharply detailed image by James D Wray directly from his atlas with my mobile camera. (And I haven't figured out how to crop images that I take with my mobile phone.)

But seriously, people, this might be the only picture in existence of Supernova 1979C, which was a remarkably bright supernova back in 1979. Consider this: Seven (7) supernovas have been detected in M100 since 1901, and SN 1979C was three magnitudes brighter than any of the other six! SN 1979C was mighty! It was superb!

The Wikipedia article on M100 lists all the seven supernovas, but it fails to mention the peak brightness of SN 1979C! Instead it talks about SN 1979C as if it faded too quickly for us to know much about it!

But the peak apparent magnitude of SN 1979C is mentioned in the Wikipedia article on the supernova itself!!

And to think that James D. Wray managed to photograph this supernova when he was photographing galaxies for his atlas!!!

Ann

[AVAO]

M100: A Grand Design Spiral Galaxy

I like this great galaxy too. This is also very exciting in IR.



Image source: SST

Image source: SST/JWST

Image source: SST/JWST

Image source: JWST/HST

Image source: HST

jac berne (flickr)
https://www.flickr.com/photos/185130090@N02/

[Ironwood]

There's a mistake in today's description. On APOD, you must say "well coiffed" whenever referring to Coma Berenices. I'm going to let it go this time, but please try to be more accurate in the future.

Ann, please fix all the astronomical mistakes you encounter on Wikipedia.

[De58te]

Speaking of mistakes in the description (possible mistake?) it says that M100 is 56 million light-years from Coma Berenices. I would rather like to know how far M100 is away from the Solar System? Wiki says that the nearest star in Coma Berenices is some 27 ly away. Would that mean that M100 is 56 million PLUS 27 light years away from the Solar System? That is some rather fine measurements. Talk about splitting 'hairs'.

[Chris Peterson]

Speaking of mistakes in the description (possible mistake?) it says that M100 is 56 million light-years from Coma Berenices. I would rather like to know how far M100 is away from the Solar System? Wiki says that the nearest star in Coma Berenices is some 27 ly away. Would that mean that M100 is 56 million PLUS 27 light years away from the Solar System? That is some rather fine measurements. Talk about splitting 'hairs'.

I'm not finding anything in the caption that says M100 is 56 million ly from Coma Berenices.

As always, the editors use the unconventional terminology of saying an object is "towards" a constellation, rather than "in" a constellation. But other than that, nothing else stands out.

[Ann]

Ann, please fix all the astronomical mistakes you encounter on Wikipedia.

How do I do that? I'm not allowed to write anything on Wikipedia.

Ann

[Chris Peterson]

Ann, please fix all the astronomical mistakes you encounter on Wikipedia.

How do I do that? I'm not allowed to write anything on Wikipedia.

Ann

You are if you create an account for yourself.

[johnnydeep]

Ann, please fix all the astronomical mistakes you encounter on Wikipedia.

How do I do that? I'm not allowed to write anything on Wikipedia.

Ann

You are if you create an account for yourself.

Yup. It's updatable by all, which is what makes it prone to human error - or deliberate abuse - but it's also what makes it self-correcting!

[orin stepanek]

M100 is a beautiful galaxy; but so are a lot of others! So why is it a
grand design?

[starsurfer]

I wonder if Judy has ever been to St Louis?

[Cousin Ricky]

Speaking of Judy Schmidt, has anyone heard from her lately?

[Avalon]

Fantastic image! Is there an explanation for the "loop" in the spiral arm just 1 o'clock from the galactic center in this view? Is it an area of intense stellar wind or ?

[johnnydeep]

Fantastic image! Is there an explanation for the "loop" in the spiral arm just 1 o'clock from the galactic center in this view? Is it an area of intense stellar wind or ?

Whether it's deemed a "loop" or "bubble", I think it's just our eyes finding apparent structure with no meaningful cause.

EDIT: although, having said that, there is a similar "bubble" on the other side, though it's less well defined:

So, does either bubble signify some meaningful underlying creation mechanism beyond random chance? I still say, probable not.