Z Canis Majoris -- a brightening jet-feature?

[ngcles]

Hi All,

Here's something of interest to observe tonight.

Via the AMASTRO mailing list, American amateur Jerry Lodriguss has flagged a possible brightening within a jet associated with the variable star Z Canis Majoris on the Canis/Monoceros border close-by to the small cluster/knot of stars VdBergh 92 and embedded in the extended nebula IC 2177.

Z Canis Majoris is a pre main-sequence T-Tauri type variable with a spectral class of B8pe that is coughing and spluttering its way though birth pangs.
The star itself underwent a significant outburst (2-3 mags) in 2008. There is a fairly strong jet associated with the star in PA 300 extending up to an arc-minute (a few light years) long. This jet or parts of it have apparently brightened somewhat recently, likely as a result of the recent activity of the host star.

You can compare images here:

http://www.astropix.com/Z_CaM/Wang1.HTM

showing a substantial difference between the blue and red POSS1 & POSS 2 and a recent RGB colour image. Looks as though this jet might be quite visible in smallish/moderate-sized telescopes.

Here is a light curve for Z CMa from the AAVSO for the last several years:

http://www.aavso.org/lcg/plot?auid=000-BBM-325&starname=Z%20CMA&lastdays=200
0&start=&stop=2455569.65155&obscode=&obscode_symbol=2&obstotals=yes&grid=on&
visual=on&uband=on&bband=on&v=on&pointsize=1&width=600&height=450&mag1=&mag2
=&mean=&vmean=

(Let's hope the link doesn't break!)

Interesting at least and something to take a peek at. Hoping for a few hours tonight out at my southern highlands spot!


Best,

Les D

[astroron]

Thanks Les . Let us know how you get on :thumbsup:
I hope to have my Mirror back next week, could be a good target for first light:D:thumbsup:
Cheers

[Rob_K]

Thanks Les - the link was broken, but even with a copy-&-paste it didn't seem to bring up the light curve. I've attached the light curve from AAVSO data for the last 2000 days (~6 years). An interesting one! :thumbsup:

Cheers -

[mithrandir]

It did break. This (http://www.aavso.org/lcg/plot?auid=000-BBM-325&starname=Z%20CMA&lastdays=2000&start=&stop=2455569.65155&obscode=&obscode_symbol=2&obstotals=yes&grid=on&visual=on&uband=on&bband=on&v=on&pointsize=1&width=600&height=450&mag1=&mag2=&mean=&vmean=) one works.

Pasting links into a message body is chancey. It's much safer to select some relevant text, click the "Insert Link" button, and paste the link.

Andrew

[Rob_K]

Here's some help finding it - a wide simulation based on southern view in late evening (generated in Starry Night), and some DSS images at various scales, taken from Aladin v7.0. As Les said, it's on the shoulder of the wing of the "Seagull", IC 2177, a popular imaging target on IIS. Position is RA 07:03:43.16, Dec -11:33:06.2 (J2000).

Cheers -

[mental4astro]

For a moment I thought there might be a chance to have a crack at this one tonight. I advanced two steps towards the scope and CLOUDS!

Most interesting development.

It will be interesting to see just how much this jet brightens.

[Suzy]

Thanks for posting that information Les. :)
I would so love to take a look at this, but doesn't seem likely for a while with the bad weather we're having. Looking forward to reports from others that get a chance to do so.

[orestis]

Thanks les for the info,

Just wondering how bright it is and if i would be able to observe it through a 5'' scope.

Thanks in advance
Orestis:thumbsup:

[ngcles]

Hi Orestis,



Hard to say, 5" is probably a bit small based on the image, but I'd think 10-12" should do it at x200-x250. Really only one way to find out though!

Thanks for fixing my broken links guys and adding the extra pics.:thumbsup:

I didn't get to have a go at it last night and was clouded out yet again when I was starting to look like I might get a few productive hours in. Oh well, another night ...


Best,

Les D

[Paddy]

Thanks Les for the information and Rob for the charts. Will have a crack.

[mozzie]

had a look at z canis majoris seeing was fair nice and dark before moon rise was unable to see anything,well maybe a little flaring but was unshore will try again when clouds disappear.....

[Rob_K]

Oh well, here's a 'baseline' obs. Quite reasonable skies tonight, NELM about 6, so had a go with 4.5" f8 reflector at 43x and 113x, the lower power just to be certain I was in the right spot. Z CMa was quite easy to find - the little nest of stars nearby make it snap.

So.... nothing there! It's difficult trying to make out a feature like this because the light from stars does funny things to your eyes. In staring at it for so long I saw, at times, little jets in just about every direction possible! But a simple 'control' test was to go to a similar mag star, and the same effects were observed. Further, there was nothing you could hold.

I suspect this may be very difficult visually, even for larger apertures. Most info I've seen points to the jet (and at times jets, eg 2008) being strong in the near-infrared.

Next please, let's work up through the apertures until someone can see it! :D

(On a better note, I finally saw the Homonculus through my scope at 112x - only one tiny golden lobe could be held in direct vision, but averted vision worked, kinda! Satisfied that this is not in any way a small scope target, so I wouldn't recommend anyone with a small scope like mine to bother - I won't again. At high powers through a bigger scope it is awesome).

Cheers -

[ngcles]

Hi All,

A positive observing report has been noted on AMASTRO where the object was described as "easy" at x488, though the dog-leg bend was not visible. It was also described as "the neatest thing I've seen in a long time".

... mind you it was with a 1.25m (48") aperture Dobson mounted Newtonian. This 'scope is apparently the largest amateur 'scope in the world and perhaps somewhat predictably situated in Texas, U.S.A.

If the sky co-operates, I'll take a peek tomorrow night out at my Southern Highlands "nearly dark" spot with my tiny 0.46m ...


Best,

Les D

[astroron]

Hi Les
I attempted it last night 16"+6mm Radian ,but had left it a bit late and the seeing had detariated,and did not see it,but will give it another go tonight.
Cheers:thumbsup:

[Merlin66]

Sounds like a good candidate for a spectroscope!!!

[astroron]

I have just come in after observing Z Canis Majoris on and off in very mediocre Seeing and the best I can say was a maybe in periods of better seeing:shrug:
When returning to the star after a little time away a faint haze was seen but then the brightness of the star itself overwhelmed the nebulosity the more you looked at it.
Eye pieces used 6mm Radian and 2.5 mm Barlow
Needs better seeing I think to get a definite yes or no.
Cheers

[ngcles]

Hi All,

More details later -- just got home from Bargo and it is about 6am. Can report a positive sighting of the jet from Z Canis Majoris confirmed by three other observers (1x very experienced, 1x moderately experienced, 1x beginner-moderately experienced).

x317 unfiltered was best. Suspected at x185. x247 difficult but not overly so averted vision essential. Best at x317 -- still A.V. Any filter kills it stone dead. Suspect minimum aperture will be in the 14-16" range. Very LSB and small but definite. Z Cma despite the spectral classification, seems weakly yellowish at x247. Seeing 6/10. SQM-L = 21.22

Happy boy! Suspect I may be the first southern hemisphere observer to detect it visually :)


Best,

Les D

[Rob_K]

Great work Les! :thumbsup: May see if I can get some "big scope time" at Snake Valley in a few weeks to have a go.

Keep at it Ron, I'm sure you'll get it, especially with the information in Les' observation.

Cheers -

[Rob_K]

Here's an interesting image from 28 January, showing the jet on Z CMa, the Seagull Nebula, and comet 103P Hartley:

http://udalosti.astronomy.cz/wp-content/20110128-103p-ngc2177-seagull.jpg

Cheers -

[astroron]

Hi Rob,I saw what Les reported, but Les has two more inches of mirror and some other observers to confirm his observation:shrug:
I too used averted Vision, which was when the wisp was most visible.

I think the weather is going to put off any more observing for a couple of days at least:sadeyes:
Cheers

[pgc hunter]

Wonder how I missed this thread... very interesting new development here and a nice new visual challenge to try my luck on!

Nice work Les! I'll give it a crack next clear night, hoping for good seeing so can ramp up the mag. Brings to mind another CMA object - VY Canis Majoris, has anyone ever seen the nebulosity around this star?

[Merlin66]

A couple of close up images would be nice to see!

[astroron]

Sab VY Canis Majoris is one of my favourite objects in CM:D it is a mini Homunculus with the bottom lobe missing, But has also been compared to the NIKE Swish:shrug:
Cheers

[pgc hunter]

:thumbsup: sweeet as! I had this object at the back of my mind for a while now but never got 'round to it. Thanks Ron your obs is encouraging, will make sure to check it out next time. Sounds like I'm in with a decent shot ;)

[Rob_K]

A VSNET Alert has been put out about Z CMa:



Recent obs are included in the alert:

http://ooruri.kusastro.kyoto-u.ac.jp/mailarchive/vsnet-alert/12767


Cheers -

[Rob_K]

AAVSO have now put up a Special Notice about the current 'outburst' of Z CMa, calling for observations:



http://www.aavso.org/aavso-special-notice-232


Cheers -