Object of the Week Aug 24, 2014 – ETHOS 1 (not THAT Ethos)

ETHOS 1

RA/Dec: 19 16 31.5 +36 09 48
Size: 19"
Mag: V ≈ 15
Type: PN
Aliases: PN G068.1+11.0

ETHOS -- that's the Extremely Turquoise Halo Object Survey, which seeks to find compact, high galactic latitude planetary nebulae that would normally be missed by searches close to the galactic equator. ETHOS 1 lies at a galactic latitude of 11°, just beyond the 10° range, where PN are typically found.

Discovery images revealed twin jet outflows oriented northwest and southeast, extending from a compact, circular disc, ~12" diameter. Follow-up studies also revealed a very tight, binary central star, hypothesized to be responsible for the symmetric bi-polar jets.

A December 2010 announcement can be read here or you can read the full 2011 MNRAS paper "ETHOS 1: a high-latitude planetary nebula with jets forged by a post-common-envelope binary central star"

The paper includes the following montage using various filters (the color image is a composite of H-alpha and [N II])

Attachment 1342

Here's a general field in the "colorized" DSS from WikiSky. The bright star towards the upper left is mag 10.6 and just 2.8' ENE of Ethos 1.

Attachment 1344

This object was high on my observing list during a visit to Jimi's in 2011. How much of this structure was visible and could the jets be seen? Here are my notes ...

At 375x, a very small round glow, ~15" diameter, was easily seen surrounding a faint central star. Very faint wings or jets extended SW and NE. At 488x the jets were easily visible with a Sloan G filter. With this combination, the planetary resembled an edge-on galaxy, ~40" in length, with a brighter core. A faint star (actually a double) is near the SE tip, while the NW extension has a faint star (also double) just east of the tip. The jets were visible without a filter, though not as well defined.

I believe an 18" will show at least the central region in excellent conditions. From a not-so-dark site on the outskirts of the San Francisco bay area Ethos 1 was visible in my 24-inch, the central portion was picked up at 225x, but was better seen at 285x. I tried an NPB filiter, but contrast was only improved marginally at 225x, if at all. I wasn't certain if the "jets" were visible in these mediocre conditions. Helping to pinpoint the location is a 48" string of three mag 13.3/13.7/14.3 stars about 1.5' N of Ethos 1 and a mag 15 star just 35" NE.

If you've already tried this object, what were the results? Otherwise as always ...

“GIVE IT A GO AND LET US KNOW”
GOOD LUCK AND GREAT VIEWING!

Nice object Steve!

Like you, I also saw it with Jimi's 48" and have similar notes.


A few months later (July 2011), I decided to try it with my 22" at IHOP. The conditions were average (NELM 6.8)
22" (383x) - Very faint, 2:1 elongated glow. Even surface brightness, PA = 135 and about 0.5' long. The Lumicon UHC filter makes it disappear, but the Astronomik CLS filter helps a little. I suspect that the “elongated” tips (jets) are the two double stars along the same axis as the jets.
This one of the new planetaries discussed on AmAstro.

Then I tried it again at Shot Rock (August 2011) under better conditions (NELM 7.2 overhead). My notes are below:
22” f/4 (230 and 383x) – Very faint, 3:1 elongated glow. Ultrablock makes it disappear and the CLS filter helps quite a bit. The CLS slightly enhances the two lobes, so I’m’ pretty sure that I observed the nebulous lobes, not the double stars as suspected after the last session. PA = 150 and about 1’ long.


Steve, with better conditions you should be able to get the lobes with your 24".

I observed this guy twice with my 27", both times under very good transparency.

27", 419x, Seeing IV, NELM 7m+ (Aug 2011)
from 172x faint disk visible; with 419x round disk which I can hold steadily without filter with averted vision; CS is popping in and out of view; on both sides faint extensions, I suspect these comes from the both close DS in the lobe axis, but I'm not sure; PN is a little bit better defined with UHC but did not react very positive on filter

27", 586x, Seeing III, NELM 7m+ (Aug 2013)
faint but visible with direct vision; bad reaction on filter, best view without; CS visible in the middle round part; in both lobe axis very faint double stars popping out which can not resolve as two stars, sure that the extensions are the stars and not the lobes

So in my opinion the stars are the first which is visible in the say 20"-30" range.

Steve, Alvin, Jimi, what were your results with the 48" in question of what detail were simpler in this big aperture? That should be the answer for the star/lobe question with smaller aperture. Unfortunately I had no Sloan G filter.

I observed ETHOS 1 with 25“ in August 2013 at 2000ft. under fairly dark skies (Schwaebische Alb). I could see the central disk at times directly, but mostly in averted vision. The central star showed up now and then. As for the jets, I qualified my observation as highly dubious. What I saw was most likely the double stars, not the jets. Filters (OIII and UHC) did not help.

Johannes

I have an observation from 2011 as well:

"Now this is an interesting object! Surprisingly easy to locate it was also not difficult to see. With direct vision I could see its central star and with averted vision its round nebula popped out. It appears that it has two stars on either side that line up in a straight line giving Ethos 1 the look of having wings, and in a few moments of clarity they barely popped out, as did another line of stars at a 90 degree angle. 408x, 21.62 SQM."

Attachment 1345 Attachment 1346

Neither my notes or memory recall if I was wondering about seeing the nebulous wings as well as the line of double stars, but my guess is that I only saw the stars. I also don't remember if I was looking for the nebulous wings, so this is a good reason for another observation. Although my notes don't mention trying filters (NPB, OIII, h-beta) I'm pretty sure I did and found they didn't help.

I observed Ethos 1 this night 24/25 Oct with 24" (528x) scope at NMAV in NM near Silver City. I saw its central part as star like object. The wings or CS or those double stars besides wings could not be seen. Drawing can be seen next week when back home. SQM-L readings were 21.2. Much humidity in the air and some air glow.

Here finally
is the promised drawing of my ETHOS 1 observationAttachment 1758