A faint ring-like object in NGC 1818 (APOD 29 Dec 2002)

Arbytronix · Post by **Arbytronix** » Wed Oct 25, 2006 12:13 pm

I had the recent opportunity to enjoy the following page from Astronomy Picture of the Day. http://antwrp.gsfc.nasa.gov/apod/ap021229.html My eye was drawn toward a small feature when I looked at the larger image: http://antwrp.gsfc.nasa.gov/apod/image/ ... st_big.jpg .

In the upper quarter of the larger image, between and slightly above a bright green star and a dimmer white star, I noticed a faint loop structure. To be ever so blunt in my questioning; what am I seeing?

A hint may be provided by a similar loop structure found near the botttom of the image in close proximity to a very bright yellow star.

orin stepanek · Post by **orin stepanek** » Wed Oct 25, 2006 2:04 pm

I take it you are talking about the 2oclock position from the green star. In my opinion it may be a bubble. Really it is too small to tell for sure.

Orin

BMAONE23 · Post by **BMAONE23** » Wed Oct 25, 2006 5:01 pm

There is another one next to (8:30) the large red star near the bottom of the image.

orin stepanek · Post by **orin stepanek** » Wed Oct 25, 2006 5:05 pm

BMAONE23 wrote:There is another one next to (8:30) the large red star near the bottom of the image.

That one has a red hue to it!
Orin

Arbytronix · Post by **Arbytronix** » Tue Oct 31, 2006 5:54 pm

Well the mystery is sovled. The mysterius bubble like objects were reflections in the Hubble Optics.

The following quote is a response from Dr. Deidre Hunter, the individual responsible for the imaging.

"It looks like a reflection from the very bright star to the lower left of it.

Deidre Hunter"

So, no new discoveries, but it may be interesting to look at other Hubble images to see if the reflecttion artifact can be seen as well.

Ron

BMAONE23 · Post by **BMAONE23** » Tue Oct 31, 2006 6:12 pm

Not that I doubt the explination of an Expert, but I was under the impression that optical reflections appeared in similar orientation in photographic images taken at or near from the same relative source point. The green Ring by the green star appears at the 2:00 location in relation to the star (approx 30 deg north of east) the ring structure near the red star appears at the 8:30 location about 10 deg south of west. While lense flares can appear on both sides of a bright light source, they usually appear in a straight line 30 deg n of e vs 30 deg s of w. These are 30 deg n of e and 10 deg s of w.

Qev · Post by **Qev** » Tue Oct 31, 2006 7:51 pm

BMAONE23 wrote:Not that I doubt the explination of an Expert, but I was under the impression that optical reflections appeared in similar orientation in photographic images taken at or near from the same relative source point.

Isn't each section of the image taken by individual imaging components? At least, that's my rough understanding of how Hubble works...