11 replies to this topic

[blakesphere]

I took up the Sky & Telescope recent doubles challenge.

 

I tried to view omicron (ο) 2 Orionis.

 

aka SAO 94218, HIP 22957, BU (Burnham) 553, 9 Ori.

 

I don't want to make any spoilers here...

 

I'm curious what you see.

 

 

[Stellar1]

I'm curious about what you mean, have you had a look at it and noticed something odd? or do you not see what others are seeing? It's been a good while since I've had a look at doubles in that vicinity.

[blakesphere]

Well, it's a triple.

 

The 2 companions are not particularly challenging. WDS data updated circa 2013. Magnitude values look doable.

 

But I couldn't see them!

 

There's always the chance I was in the wrong field but checked a few times. I was certain I was in the right spot.

 

8" SCT, baader zoom eyepiece, SkyTools 4 Visual, fair to good seeing, average transparency, urban sky.

 

So I'm just curious people's assessment of this system. Was it easy or challenging?

[flt158]

What's your Bortle, Blake?

I must confess I have never observed Omicron Orionis. 

Presumably you had no Moon in your sky. 

 

Best regards from Aubrey.  

[yuzameh]

Dunno, it's optical, both B and C seem to actually both of similar mag and not a mag apart, quite different proper motions so c has moved a bit relative to a, ac 111" in 69d in 2016, 41" in 53d for ab.  b's probably mag 12.5 and c around mag 12.0, which is also not just a bit fainter than WDS but bc are reversed in brightness relative to WDS.  So b may be a whole mage fainter than you are expecting whilst c is a bit fainter than thought it should be.  Although it's a wide pair this is at least 8 mags worth of mag difference, and if you have image spikes or something because of the bright primary you could have just been unlucky as it's nearly a straight line triple.

Edited by yuzameh, 20 January 2023 - 09:27 AM.

[blakesphere]

I'm probably a Bortle 5 or 6. I have yet to do a NELM.

 

In the C8, I've reached mag 14--in dark sites of course!

 

I recently collimated (and it's nearly perfect).

 

That evening, last weekend, I was seeing mag 11 field stars, maybe a couple of mag 12.

 

That's what was confusing me. I thought I'd be able to tag the companions, despite the bright primary. I saw Rigel B no problem!

 

I guess I was on the wrong star...

 

I really wanted to hear from people who have seen omicron Ori lately to see if something had changed...

[yuzameh]

.

 

I really wanted to hear from people who have seen omicron Ori lately to see if something had changed...

 

Nope, nothing's changed, the WDS values for 2013 and the gaia values for 2016 for sep and pa show little discernible change, it's just the mags are a bit off in WDS which is not a new thing as can be seen in many threads.

 

I know you'd be happier if someone observerd it but frankly they are not going to be any better than gaia at confirming things, the proper motion differences will have made a bit of difference in the six plus years since gaia but it will below what you can make out at an eyepiece just by eye.

[CHnuschti]

Not seen it, since out of my "range".
Checking it in aladin (lite), it gives in G magnitude, pretty much the equivalent of the usual V mag:
B: 12.7m
C: 11.9m
So fainter as what WDS catalog says.

 

https://www.cloudyni.../#entry12412752

 

regards

[dmdouglass]

Blake...

 

Had a chance this evening to image this target... See Below.

The larger image is from a stack of 5 2sec exposures. The primary star sort of gets "blown out", which may be part of your issue.

 

The smaller image, (upper right) is from a single 2sec exposure which shows the triple nicely.

 

Hope this helps.

.

[blakesphere]

Thank you so much, David, for the image.

 

I will dive deep into it to find those pesky companions.

 

Or maybe it will reveal I was on the wrong star!

[dmdouglass]

Looking forward to hearing the results of your search...

[c2m2t]

Hi Blake!

I suspect the reason for you not being able to resolve the B & C components is that the magnitude data is suspect...at least according to the GAIA data. I have attached my typical narrow field images...one with and 1 without notation along with a not so well focused wide field image centered on 9 Ori as well as the DSS image and GAIA data from Aladin. I do believe a bit more optics will be required or some exceptional conditions...and you know how often we get that in this part of North America!!  

 

Cheers, Chris.

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