II Zwicky 5

[KidOrion]

I stumbled across this tiny galaxy on Sky Atlas 2000.0 Chart 10, thinking that it was unusual for one of the Zwicky galaxies to be drawn on a chart intended for 8-14" scopes (there's one other Zwicky galaxy in SA 2000). Interested in its presence in the atlas, I checked the Sky Atlas 2000.0 Companion, which was rather (expectedly) short on details. I then checked both versions of Uranometria 2000.0, only to find it missing from both. It does appear on José Torres' TriAtlas C charts, and it turns up on the Palomar Sky Survey. However, there's a distinct lack of observing reports regarding this little galaxy; there's an OR from Jamie Dillon that mentions it, but little else. (Even a search of CloudyNights turned up nothing.)

Has anyone observed this galaxy? (I'm sure at least a few of you guys have.) What would be the minimum requirements to view it?

[Steve Gottlieb]

Wow, this is an interesting situation. The NED position for II Zw 5 falls on a star with an extremely faint and tiny galaxy attached, though there happens to be a larger, faint galaxy about 1' north. NED has two images -- one from the DSS (on the star) and the image from Zwicky's CGPG, which also points to the same star!

As far as the galaxy 1' north, NED identifies it separately as 2MASX J02411986+0413173 and HyperLeda misidentifies II Zw 5 as 2MASX J02411986+0413173! (see http://leda.univ-lyon1.fr/ledacat.cgi?o=2ZW005).

In any case, why is this object (bright star + extremely faint galaxy) included in Sky Atlas 2000.0 in the first place???

Zwicky's description reads "Blue extremely compact. With jet (galaxy + superposed star)
m(pg) = 11.8.

I'm sure Zwicky's bright magnitude (11.8) is the only reason II Zw 5 made it into the SA 2000. But the magnitude applies to the star, not the extremely faint galaxy!

I haven't checked, but I wonder if this object was discussed previously on the amastro group?

[Jimi Lowrey]

I was just looking at this too Steve.

MagaStar has the 2MASX galaxy as II ZW 5 but it is clearly by the notes in Zwicky's red book the compact galaxy by the bright star.

I too wounder how it got in Sky Atlas 2000?

SDSS image
310

[Jimi Lowrey]

KidOrion what was the other Zwicky galaxy in Sky Atlas 2000, you have got my curiosity up.

From the Sloan photometry II ZW 5 is aprox 17.31 V MAG. I think by how close it is to the bright star that it would be a really tough object in most any telescope. But who knows give it a try and see what you see.

[KidOrion]

Jimi--

According to the SA 2000 Companion, the other Zwicky is III Zw 66, on charts 13, 14, and B1, about a degree WSW of M88. The book lists it as "very small and round."

As to II Zw 5, it's listed as "Faint, small, and round." Bit of a no-brainer, actually!

[KidOrion]

At the risk of dredging up a topic that may have not been all that interesting to start with, I got the Jumbo Pocket Sky Atlas this Christmas, and II Zw 5 is right there on Chart 4.

Strange.

[Steve Gottlieb]

Clearly the object was plotted in all 3 atlases (its also in the original Pocket Sky Atlas) based on the erroneous Zwicky magnitude. If anyone had first looked up an image of II Zw 5, it would not have been included.