Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Antares at low power

  • Please log in to reply
7 replies to this topic

#1 leonard

leonard

    Apollo

  • *****
  • topic starter
  • Posts: 1,345
  • Joined: 19 Oct 2007
  • Loc: West Virginia

Posted 18 June 2021 - 10:53 AM

Hello ,

 

           Over the years my observing interest concentrated for the most part on clusters

and bright galaxies . Every so often I would check out a double star . One of my first doubles 

was Antares , many years ago with a 4 inch refractor working at an exit pupil of about 0.75 .

A superb sight to behold . On Wednesday night here in the hills after the moon set , the Milky

Way was well defined and the seeing was good but not great . I just made an alignment of my

green laser on the North Star and moving the scope around to the south pointed the scope 

at Antares for no real reason at all . Had my low power eyepiece a Baader Hyperion 36mm

in my 120 refractor giving a magnification of 28 X , focused on the star and was ready to move over to M4 for a high power view of the cluster . I looked closely at Antares and the very tiny secondary caught my eye .

I keep viewing and saw that the secondary was visible about 50% of any time period .

Having little experience at this sort of thing , at first I thought it unusual to see it at low power .

As the night moved on , I would come back to Antares to view a couple of times just to confirm

the secondary .

On Thursday as the moon set , I viewed again although with a different low power eyepiece ,

a Parks gold series 35mm 1.4 eyepiece and although the night sky conditions was just a 

little less than Wed. the secondary was seen just a little better in this eyepiece for what ever

reason , visible about 60/65 % of the time . That the secondary is not all that dim (5.5 mag)

and the fact I was using a refractor vs a reflector I think was a big help .

So any other low power observations of this star ? It’s very small and very close to the

primary .

 


  • Carbstone and Voyager 3 like this

#2 MisterDan

MisterDan

    Viking 1

  • *****
  • Posts: 760
  • Joined: 20 Jun 2014
  • Loc: Colorado

Posted 18 June 2021 - 11:09 AM

Hmmm... I guess I'll just have to check and see. waytogo.gif

 

I do sometimes try some "how-low-can-you-go" experimentation with various targets.  Lyra's Double-Double, Izar, Rigel, etc.  I don't recall ever trying that "method" with Antares.

 

Thanks! and best wishes.

Dan


  • leonard likes this

#3 John Fitzgerald

John Fitzgerald

    In Focus

  • *****
  • Posts: 10,323
  • Joined: 04 Jan 2004
  • Loc: near Elkins and Pettigrew, Arkansas

Posted 18 June 2021 - 11:28 AM

I think that seeing a split of the Antares double at less than approximately 100x is probably not credible.  At 28x? Probably impossible, IMO.  The few times I have observed it, I had to use around 200x, to get enough separation from the glare of the primary star.  Many times, artifacts around bright stars are seen at lower powers and larger exit pupils.


Edited by John Fitzgerald, 18 June 2021 - 05:03 PM.

  • Bonco2 likes this

#4 leonard

leonard

    Apollo

  • *****
  • topic starter
  • Posts: 1,345
  • Joined: 19 Oct 2007
  • Loc: West Virginia

Posted 18 June 2021 - 01:35 PM

I think that seeing a split of the Antares double at less than approximately 100x is probably not credible.  At 28x? Probably impossible, IMO.  The few times I have observed it, I had to use around 200x, to get enough separation from the glare of the primary star.  Many times, artifacts around bright stars are seen at lower powers and larger exit pupils.

          Yes , this was my thinking also at first . When I keep repeating the observation at different times and the next night 

using a different eyepiece has convinced me it’s real . Of course it could be a near by star of low magnitude , but it’s at

the proper position angle . Needs looking into and more observations .

Could be like a lot of old timers that found a small gold nugget and felt there was a gold vain up in them hills only 

to eat bread , fatback and beans for the rest of there life .


  • Voyager 3 likes this

#5 barbie

barbie

    Surveyor 1

  • *****
  • Posts: 1,922
  • Joined: 28 Jan 2013
  • Loc: Northeast Ohio

Posted 18 June 2021 - 02:43 PM

To get a good split on Antares, I had to use 200x plus with my 76mm fluorite apochromatic refractor under excellent seeing last summer. This happens for me on average about once every 10 years or so.



#6 Bonco2

Bonco2

    Viking 1

  • *****
  • Posts: 732
  • Joined: 01 Jun 2013

Posted 18 June 2021 - 03:56 PM

Me thinks you're seeing some aberration. Usually around 200X for me to view it with a 4 inch telescope. AND only on very steady nights. It's a tough one.

Bill


  • John Fitzgerald and flt158 like this

#7 John Fitzgerald

John Fitzgerald

    In Focus

  • *****
  • Posts: 10,323
  • Joined: 04 Jan 2004
  • Loc: near Elkins and Pettigrew, Arkansas

Posted 18 June 2021 - 05:13 PM

Me thinks you're seeing some aberration. Usually around 200X for me to view it with a 4 inch telescope. AND only on very steady nights. It's a tough one.

Bill

Yes, an aberration of some sort is being seen.  The brilliance of the Antares primary tends to spread out the image due to irradiation, and well over 100x is likely required to get enough separation, plus near perfect seeing is required.  The current separation is given in the WDS as 2.62 seconds.  Any report of a sighting of the companion at low powers is quite dubious.  I think that, presently, this double is more difficult than Sirius, at least north of the tropics.  Its low altitude culmination adds to the difficulty.


Edited by John Fitzgerald, 18 June 2021 - 07:30 PM.

  • Bonco2 and flt158 like this

#8 Cotts

Cotts

    Just Wondering

  • *****
  • Posts: 11,374
  • Joined: 10 Oct 2005
  • Loc: Madoc, Ontario

Posted 18 June 2021 - 07:06 PM

The nearest star to Antares that could even be remotely thought to be the 'companion' of Antares , 6th magnitude or brighter is SAO 184437, Mag 6.0.  It is half  a degree away in totally the wrong direction.   There are no stars within 2 arc minutes of Antares brighter than 12th magnitude.

 

So, only one conclusion..

 

Dave


  • Bonco2 and flt158 like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics