HH 222 [Waterfall]

[Jimi Lowrey]

I looked at HH 222 the waterfall last week after viewing NGC 1999. I must say this is a difficult object. The only part that I could see was the small brighter patch near the star that I have marked in the image below. It was seen as small extremely dim patch with AV only. I tried several filters and high and low power but it did not help it any. The best view that night was with a 10MM ZAO @ 488X unfiltered. The waterfall shape of this nebula was NOT seen.

484

[reiner]

This one had been on my to-do list for some time, but I never made it to try to observe it (also in part due to the unfavorable wheather here during the past new moon periods). Your report indicates that this is likely no object for the +/- 20" class Dobs. I had hoped it would react to filters... :-(

Did you try as well the small but possibly brighter bow shock of HH34 at the S end of HH 222?

http://www.eso.org/public/images/eso9948c/

[Jimi Lowrey]

Reiner,

I did not try HH34. I will try HH 222 again when the moon is out of the way and then try for HH34, it looks about the same brightness as the bright spot that I could see in HH222. I will report what I find then.

[Steve Gottlieb]

To add to the number of comments about the visibility -- and difficulty -- of HH 222, here are a couple of positive sightings and a negative report from four very experienced observers back in October 2000 on amastro.

Jay McNeil (16-inch): I observed HH 222 back in December of last year from a very dark site located in rural Mississippi (NELM at Z ~7.0). It was pretty chilly that night (~29F -- hey, don't laugh, 'cause that's pretty darn cold for us southerners), and the seeing was suprisingly good despite the recent cold front passing through. This object was included in a rather extensive list of Herbig-Haro objects located in the L1641 region of Orion that I had set forth to observe. HH 222 was extremely difficult to detect and required 586x (7mm +2x Barlow on my 16-inch f/5.1). My notes recall a very difficult object (averted vision only -- less than 50% of the time) resembling a very small but apparently elongated edge-on galaxy less than 1' in length and oriented in a NE-SW direction. A faint but obvious star of ~16th magnitude could be glimpsed lying just to the NW of the object in nearly the same direction as the brighter 10th magnitude star designated as GSC 4778:1107.

In order to reference how good of a night it was, the previous observation in my notes reveal HH 1 and HH 2 with the same scope and power to both be fairly easy direct vision objects that appeared conspicuously nonstellar during moments of good seeing. Unfortunately, the only other positive HH object observation of the area was a "highly suspected" sighting of HH 130. Put simply, these things are an absolute thrill to hunt down, but they often require very high powers and really good conditions in order to detect at all. Hope this helps.....and I would truly love to hear of anyone's success in detecting these guys...

Dave Riddle (18-inch): Nope, I couldn't see the "Waterfall" nebula with an 18" reflector earlier this year at the Winter Star Party. For us designation freaks, the filament is the Herbig-Haro object HH 222 and is frequently referred to to as the the "Orion Streamer". The catalogued dimensions are 10" x 300". Like they say in baseball (and especially if you are an Atlanta Braves fan) there's always next year. Maybe more aperture, more transparent, darker skies, higher magnification, blah, blah, blah will reveal this object.

Rich Jakiel (24-inch): After a few hours of general sight-seeing [at Cheifland, Fla], I finally got a chance to use the Atlanta Astronomy Club's 24-inch for more difficult objects. Perhaps the most unusual and difficult observation was of the Herbig-Haro object #222 sometimes known as the "Waterfall". After studying the reflection nebula NGC 1999 (and its stunning Bok globule) and pegging HH 1 and HH2, I proceeded nearly due north to the HH 222 field. At 304x (9mm Nagler), I was most surprised to see a mildly curved, very diffuse/faint band running south of an 8th mag field star (no filter). The band was ~ 4' x 1', with a slightly sharper inner "edge". I called over Art Russell to confirm my observations. We conducted a series of observations with a variety of filters:

O III : total washout; nothing visible H-Beta: only a few traces visible Broadband "Deepsky": darkened the field, most of the band remained visible. It would appear that most of the light is via reflection, though some may be low-excitation emission.

Art Russell (24-inch): Yes, we saw HH222. However, "saw" would certainly be an understatement. I've not done my notes yet, but would say that it is an EXTREMELY DIFFICULT object. Finding the field is no problem as it is conveniently located a scant 19' northwest of NGC1999. Observed at 304X in a 9mm Nagler, the object was extremely faint and did not present the appearance of a water-fall. Rather, it exhibited a very week general brightening between the two marker stars which delineate its location, GSC 4778:1107 and GSC 4778:1091. At best it was an extremely subtle feature best revealed in averted vision and when gently shaking the scope. We also tried a number of filters but found that no filtration seemed to improve the object's visibility, with a Lumicon Deep-sky filter offering a distance compromise of least bothersome as compared to the OIII which completely blacked the field, and the H-Beta filter ranking somewhere between the OIII and Deep-sky filter.

[reiner]

I tried it last night, but was not successful with my 22". Transparency was quite good, but the seeing was less than average. I also tried HH34, but couldn't see it either (this one could benefit from better seeing).

[Jimi Lowrey]

Hi Reiner,

Did you try any filters on HH34?

[reiner]

No, as the seeing was far from perfect, I spend more time on HH222 and not on the much smaller HH34.