Results 1 to 8 of 8
Like Tree1Likes
  • 1 Post By jenniferchristine

Thread: Multi color Twinkle of Sirius

  1. #1
    nizamatl's Avatar
    nizamatl is offline White Dwarf
    Points: 5,101, Level: 48
    Level completed: 76%, Points required for next Level: 49
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!365 Days+ Registered Achievement!First 1000 Experience Points
    Join Date
    Dec 2012
    Location
    india
    Posts
    22
    Points
    5,101
    Level
    48
    Thanks
    35
    Thanked 7x 4 Posts

    Default Multi color Twinkle of Sirius



    Most of the stars twinkle with a single color. But Sirius shows different colors ( Blue to Red). I heard that the color of a star is related to its temperature. Does the multicolored twinkle of Sirius has something to do with its temperature? Or is it is created by the atmosphere that comes in between?
    NIKON 12 x 50 binoculars, Skywatcher 8" F/6 Dobsonian Telescope, Meade Series 4000 Super Plossl Eye pieces, 2X barlow and Color filter set.Orion 9X 50 RACI Finder scope, Orion Satr Shoot Solar System Color Imager IV
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  2. #2
    JoeHighfield's Avatar
    JoeHighfield is offline Main Sequence
    Points: 889, Level: 16
    Level completed: 89%, Points required for next Level: 11
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!200+ Posts Achievement!
    Join Date
    Nov 2012
    Location
    Sheffield
    Posts
    165
    Points
    889
    Level
    16
    Thanks
    6
    Thanked 45x 33 Posts

    Default Re: Multi color Twinkle of Sirius

    All stars twinkle due to the distorting effects of air moving (turbulence) in the atmosphere. Sirius is low in the sky (in the northern hemisphere) and therefore the light from it passes through more of our atmosphere than other stars and it is also very bright which magnifies the effect.

    Star colours are due to temperature - Betelgeuse is c. 3,500K and orange/red, Rigel is c. 12,500K and blue - for this temperature change on the star 'surface' to look like twinkling is unlikely (I'd probably say impossible but then somebody would probably correct me!)

  3. The Following User Says Thank You to JoeHighfield For This Useful Post:

    nizamatl (01-26-2013)

  4. #3
    skldvenom's Avatar
    skldvenom is offline HYPER GIANT
    Points: 17,533, Level: 91
    Level completed: 59%, Points required for next Level: 167
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!50 Posts Achievement!200+ Posts Achievement!
    Join Date
    Dec 2012
    Location
    Australia, 120kms North of Melbourne
    Posts
    3,158
    Points
    17,533
    Level
    91
    Thanks
    60
    Thanked 366x 344 Posts

    Default Re: Multi color Twinkle of Sirius

    Nizamatl.
    On a clear, dark night, our eyes can see about 6,000 or so stars in the sky. They seem to twinkle, or change their brightness, all the time. In fact, most of the stars are shining with a steady light. The movement of air (sometimes called turbulence) in the atmosphere of Earth causes the starlight to get slightly bent as it travels from the distant star through the atmosphere down to us on the ground. This means that some of the light reaches us directly and some gets bent slightly away. To our eyes, this makes the star seem to twinkle.
    You will notice that stars closer to the horizon will appear to twinkle more than other stars. This is because there is a lot more atmosphere between you and a star near the horizon than between you and a star higher in the sky.

    Cheers
    Steve

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Meade
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    GPS 10inch
    Saxon ED100,Saxon ED80

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

    SQM 21.25-21.85

  5. The Following User Says Thank You to skldvenom For This Useful Post:

    nizamatl (01-26-2013)

  6. #4
    Euan Mason's Avatar
    Euan Mason is offline SUPER GIANT
    Points: 5,395, Level: 50
    Level completed: 23%, Points required for next Level: 155
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!Gallery Achievement!Ghost Achievement! Averaging 5+ posts a day!
    Join Date
    Jan 2013
    Location
    New Zealand
    Posts
    745
    Points
    5,395
    Level
    50
    Thanks
    226
    Thanked 202x 164 Posts
    Blog Entries
    1

    Default Re: Multi color Twinkle of Sirius

    I agree with John. Sirius has a surface temperature of 9400 deg K, and it's only so bright because of its proximity, at 8.6 light years. Its colour index is +0.02, and so it is essentially white. Twinkling is caused by turbulence of our atmosphere, with distortion similar to what you see above a fish tank's water heater. When you see Sirius low in the sky, as it is for Northern Hemispherites right now, the extended pathway through our atmosphere plus its apparent brightness makes it twinkle with many colors.

    If you see twinkling higher in the sky, then this can ruin views through telescopes - we call it bad seeing. Seeing was once so bad during a warm NW wind in Canterbury, New Zealand, that Saturn was just a blurry yellow fuzz ball through an optically excellent 8" Dob.

    Cheers,
    Euan
    Celestron CGE1100
    C8 with Synta
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Pro
    ETX125 on
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    SmartEQ
    Lunt 60 mm H-alpha
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    "If in their geometrical conclusions two hypotheses coincide, nevertheless in physics each will have its own peculiar additional consequence." - Johannes Kepler

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  7. The Following User Says Thank You to Euan Mason For This Useful Post:

    nizamatl (01-26-2013)

  8. #5
    Euan Mason's Avatar
    Euan Mason is offline SUPER GIANT
    Points: 5,395, Level: 50
    Level completed: 23%, Points required for next Level: 155
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!Gallery Achievement!Ghost Achievement! Averaging 5+ posts a day!
    Join Date
    Jan 2013
    Location
    New Zealand
    Posts
    745
    Points
    5,395
    Level
    50
    Thanks
    226
    Thanked 202x 164 Posts
    Blog Entries
    1

    Default Re: Multi color Twinkle of Sirius

    I should add that it twinkles with many colours because differ colours of light are refracted by different amounts.
    Celestron CGE1100
    C8 with Synta
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Pro
    ETX125 on
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    SmartEQ
    Lunt 60 mm H-alpha
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    "If in their geometrical conclusions two hypotheses coincide, nevertheless in physics each will have its own peculiar additional consequence." - Johannes Kepler

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  9. The Following 2 Users Say Thank You to Euan Mason For This Useful Post:

    flytyer (01-26-2013),nizamatl (01-26-2013)

  10. #6
    flytyer's Avatar
    flytyer is offline HYPER GIANT
    Points: 10,678, Level: 71
    Level completed: 43%, Points required for next Level: 172
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!50 Posts Achievement!5 Threads Achievement!200+ Posts Achievement!
    Join Date
    Dec 2012
    Location
    Centerville, GA
    Posts
    2,077
    Points
    10,678
    Level
    71
    Thanks
    227
    Thanked 330x 325 Posts

    Default Re: Multi color Twinkle of Sirius

    Thanks for the info as well.... Always a good read to learn about things I have forgotten since school....
    billy

    32° N 83° W


    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

  11. #7
    jenniferchristine's Avatar
    jenniferchristine is offline Jedi Moderator
    Points: 76,152, Level: 100
    Level completed: 0%, Points required for next Level: 0
    Overall activity: 8.0%
    Achievements:
    200+ Posts Achievement!Ghost Achievement! Averaging 5+ posts a day!First 1000 Experience PointsGot three Friends20+ Friends Achievement!
    Join Date
    Oct 2010
    Location
    Ormeau SEQld Australia
    Posts
    11,249
    Points
    76,152
    Level
    100
    Thanks
    580
    Thanked 4,791x 3,198 Posts

    Default Re: Multi color Twinkle of Sirius

    jan 2013 sirius A and B.jpg
    Seems pretty white to me and so does Sirius B - only twinkles when it is rising or setting - this is almost directly overhead
    Lee H likes this.
    NEQ6 Pro Mount.
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    ACF 8" and
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    8" emc, Canon 450D (Rebel XSi) 18-55 and 75-300 lenses. Canon 70DW 18-135 USM and sigma 70-300. 4000 lens kit.
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    Starshoot Autoguider.
    Saxon 100 f9 Apo. Saxon20x80 Binoculars. Meade ext 125 Mak

    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    102 x F5 guide
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.
    /wide field scope. 10x10 shed with dome. Sky watcher sky adventurer mount.

  12. #8
    nizamatl's Avatar
    nizamatl is offline White Dwarf
    Points: 5,101, Level: 48
    Level completed: 76%, Points required for next Level: 49
    Overall activity: 0%
    Achievements:
    2 Posts Achievement20 Posts Achievement!5 Threads Achievement!365 Days+ Registered Achievement!First 1000 Experience Points
    Join Date
    Dec 2012
    Location
    india
    Posts
    22
    Points
    5,101
    Level
    48
    Thanks
    35
    Thanked 7x 4 Posts

    Default Re: Multi color Twinkle of Sirius

    Thanks all for the informative replies
    Nizam
    NIKON 12 x 50 binoculars, Skywatcher 8" F/6 Dobsonian Telescope, Meade Series 4000 Super Plossl Eye pieces, 2X barlow and Color filter set.Orion 9X 50 RACI Finder scope, Orion Satr Shoot Solar System Color Imager IV
    To view links or images in signatures your post count must be 5 or greater. You currently have 0 signatures.

 

 

Similar Threads

  1. Sirius and its color...
    By Pierre Naccache in forum General Stargazing Forum
    Replies: 4
    Last Post: 12-10-2012, 08:49 PM
  2. twinkle twinkle
    By Chris L Peterson in forum Amateur Astronomy Forum
    Replies: 4
    Last Post: 11-29-2009, 04:33 PM
  3. Replies: 2
    Last Post: 09-26-2008, 11:37 PM
  4. Who sung "Twinkle Twinkle Little Star" from the Dead Space trailer?
    By NellyJelly in forum General Stargazing Forum
    Replies: 0
    Last Post: 09-06-2008, 03:39 AM
  5. Twinkle twinkle little satellite...
    By Ante Perkovic in forum Amateur Astronomy Forum
    Replies: 1
    Last Post: 08-17-2004, 02:30 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBulletin® Version 4.2.0
Powered by vBulletin®
All times are GMT. The time now is 02:14 AM.