The Seeing on the 17th March WOW

[hector (Andrew)]

I decided to go observing last night and have a look at the Moon and Saturn. (yes I know my scopes don't normally focus that close). I am very glad I did.
The seeing was the best I have seen in a LONG time. The view of the moon as great but Saturn was amazing. With the seeing as good as it was I decided toi see what the Homunculus was looking like. I knew that with the 3/4 moon it would be a bit washed out and it was to a degree. the 18" and the seeing allowed me to see some amazing detail. I have adjusted a hubble image bluring it to the point where I believe it looked in the eyepiece. I have also included an original image for comparison. There is pleanty of amazing detail to be seen in the nebula with good seeing and it still had the orange hue. I was observing with the 18" f4.5 and the 7mm
type 1 nagler. Wish I had a 5mm radian to use.
The two "arms" were easily visible along with the darkening in the bright lobe. The bottom lobe of the nebula appeared a little fainter than represented in the image. What really caught my attenting and held it was the slight almost stellar brightening below the actual star. again that detail can be seen in the image bgut it appears les obvious in it. The star has also increased in brightness slightly since I last observed it if my memory serves me correctly.
I also had while observing it last night an impression of eyes in the brighter lobe. Not having noticed them before I dismised the idea. they were also only visible part of the time. When I blured the hubble image for this message I was supprised to see them again. Can you get what I mean?????
I did take the oportuninty to observe many other things but this was the highlight by far.
Andrew

[sheeny (Al)]

Interesting report Andrew! Thanks!

Al.

[ngcles]

Hi Andrew & All,

Hello mate -- long (long) time no see.

Yep, that Homunculus sure does get a work-out when the seeing is good. I've been keeping tabs on the central star and the shape of the fainter lobe for some time now. I reckon the central star reached a plateau about 18 months ago and is pretty much at stand-still -- at about mag 5.2 - 5.3 it is naked eye visible in a goodish suburban sky. But the brighter spot immediately below the star and the general faintness of the fainter lobe is what I find the most intriguing. The brighter portions of the fainter lobe are now almost "anchor-shaped" with two big bites out of the sides. Those bites though are still faintly nebulous, but much fainter than the main mass.

All-in-all it is still a pretty astonishing object and knowing what is going on (well, we've got a pretty good idea) inside that maelstrom makes it even better.

Good to hear from you!!

Best,

Les D
Contributing Editor
AS&T

[hector (Andrew)]

Thanks Les

The best view I have ever had was from Ilford a few years back. The Seeing was the best I have ever seen and Hector was operating wonderfully.
This is the observation report made at the time. I know of NO other report that gives some of these details.
The Homunculus is the small nebulae that surrounds Eta Carina. It is the
envelope of stellar material that was ejected from the star about a century ago. This is the only nebulae that shows an obvious colour, Bright orange. This colour is very striking against the star background. The initial observation was at 160x. This shows the surrounding keyhole nebulae NGC3372, which defies description. The Homunculus appears as a peanut shaped orange blob about 30" across. At 300x it appears as a bright hazy star with a lobe or bubble of material on either side, orietated SW-NE. The lobe to the SW is the brightest, and appears granular with a dark lane running through the middle which curls to the southat the end. The NE lobe is fainter and shows no internal detail The center star is about 6.5 magnitude and has a jet progecting to the north about 5" long. Averted vision at this power intensifies the colour and shows a bright knot 5" WSW of the star in the SW lobe. By increasing the magnifaction to 720x even more detail was glimpsed. In moments of perfect seeing the granulation in the NE lobe became apparent. The bright knot became visible with direct vision,and the colour remained. The dark lane seen before in the SW lobe lost some of its structure, looking more difuse and ending in a small dark hole positioned about 5" from the southern edge of the nebulae. The higher magnifaction increased the contrast. The edge of the nebulae remained sharp across the entire perimeter and the arm or jet was easily picked up. What became most noticable about the homunculus was the FAINT halo that surrounded the entire object and doubled its size. The diffuse glow had an indistinct edge and appeared evenly distributed about the object. No intermal details were seen in this faint envelope A right angle of 15th magnitude stars are positioned about 15" NW of the central star adding to the view at this power. As a side note to this observation stars of 4th magnitude and brighter had difraction rings visible, one complete ring and two partial. The seeing was the best in several years that I had seen. Reducing the magnifaction to 300x I looked for the faint halo but it would not reveal itself, probably due to the glare from the star and the nebulae.
This goes down as one of the TOP 5 objects in the entire sky.

Since this is from about 6 years back the magnitude of the central star is low by over a magnitude. this increase in brightness is I believe what has caused the fainter lob to be even fainter in appearence. The light of the star is overpowering the rest of the nebula.

Clear Skies

Andrew

[ngcles]

Hi Andrew,

Excellent observation (as per usual) of Eta Carinae -- thanks for sharing it. Some of the views I''ve had with the 18" have been jaw-dropping though I don't think I've ever had good enough seeing to observe it quite like you have described.

Agree, for truly large 'scopes on a good night it is surely in the top 5

Best

Les D

[ausastronomer (John Bambury)]

Hi Andrew,

Read my observation report from Sunday nights observing here.

http://www.iceinspace.com.au/forum/s...ad.php?t=29819

I also spent some time on the Homunculus and definately saw those two "eyes" that you refer to. I spent quite a while on it at 525X and had some tremendous views. The two eyes in the SW lobe were very distinct black holes and are visible in the hubble image you have reproduced. They were not so visible at Coonabarabran last week although I only got to about 300X on it out there.

Cheers,
John B

[§AB]

lucky you Hector! The seeing here is yet to reach the level you describe

First time I aimed my 12" at the Homunculus I could easily see the almost stellar brightening you describe and in good seeing both of those lateral jets coming out of Eta Carinae. I was surprised, as these couldn't be seen at all in my 10" reflector. But on one night a couple of weeks ago, the seeing was good, I had the 10" upto 312x and I could see the stellar brightening and one of the jets. The 12" however is far superior on this object!

I have viewed the Homuncculus in an 18" obsession, but seeing was horrid and consequently it didn't even stand up to the views in my 12" dob

It is a very unique and interesting object isn't it? Another exclusive southern hemisphere spectacle. Goddamn we are lucky if you think about it!