How Can I Measure Stellar Aberration Accurately?

Click For Summary

Discussion Overview

The discussion revolves around measuring stellar aberration, focusing on the selection of stars, optimal timing for measurements, and techniques for achieving high accuracy. Participants share their experiences and suggestions, particularly in the context of amateur astronomy in the southern hemisphere.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • Joseph expresses interest in measuring stellar aberration with a goal of better than 1" accuracy, using a stationary telescope and DSLR camera.
  • Some participants suggest Alpha Centauri as a target due to its brightness and proximity, while noting the importance of atmospheric conditions.
  • There is a discussion about the timing of measurements, with suggestions that cooler winter nights may provide better conditions due to reduced atmospheric turbulence.
  • Joseph clarifies that stellar aberration is around +/- twenty arc seconds over a year, while parallax is smaller and phase-shifted, complicating the measurement process.
  • Participants note that stellar aberration cannot use reference stars for comparison, as all stars exhibit the effect similarly.
  • Joseph seeks advice on stable telescope mounting techniques for long-term measurements.
  • There is a mention of local astronomy groups in Sydney, such as the Astronomical Society of NSW, where Joseph could seek further tips.

Areas of Agreement / Disagreement

Participants generally agree on the challenges of measuring stellar aberration and the importance of selecting appropriate stars and conditions. However, there are nuances in understanding the relationship between stellar aberration and parallax, indicating some level of disagreement or confusion among participants.

Contextual Notes

Participants express uncertainty about the best times for measurements and the specific techniques for achieving high accuracy. There are also references to atmospheric conditions and the need for stable equipment, which remain unresolved.

Who May Find This Useful

Amateur astronomers, physics enthusiasts, and those interested in observational astronomy may find this discussion relevant, particularly in the context of measuring stellar phenomena.

jk1956
Messages
3
Reaction score
0
Hi everyone,
I am interested in measuring stellar aberration as a challenge to myself; I am more of a physicist than an astronomer. I have a fair knowledge of telescopes and imaging. I would appreciate if somebody can give me instructions or point to some references on: which star to select, what time at night to conduct measurement, how often to measure etc. My goal is to obtain better than 1" accuracy. I intend to use a stationary telescope with a DSLR camera, with the recorded images analysed to determine position shift.

I am in the southern hemisphere, Sydney, Australia. I could not find a description of stellar aberration measurement procedure in my searches, except Bradley' original paper. Thanks for your interest.
Regards,
Joseph
 
Astronomy news on Phys.org
jk1956 said:
My goal is to obtain better than 1" accuracy.
Will be hard to see anything if you don't reach that. Alpha Centauri has the largest parallax at 750 milliarcseconds (not counting the slightly nearer but much dimmer Proxima Centauri).

Nearby bright stars, with more distant bright stars nearby as reference (ideally in the direction of parallax shifts), should be the best targets.
More measurements give better accurary, so does a longer timespan (probably go for a year, otherwise it is hard to separate the small parallax from the proper motion).

I don't know the best time of the night. Atmospheric turbulences should be as weak as possible.
 
jk1956 said:
which star to select, what time at night to conduct measurement, how often to measure etc.

mfb said:
I don't know the best time of the night. Atmospheric turbulences should be as weak as possible.
Hi Joseph
welcome to the Physics Forums
I am also in Sydney ( inner west)

cool winter nights are the best for lowest atmospheric turbulence ( summer not so good).
Also use Alpha Centauri as mfb suggested and when it is highest in the sky so you are looking through the least amount of atmosphere.
measuring 6 months apart will give the greatest difference in parallax measurement and you would want to do multiple measurements at each of those 6 monthly intervals to get a good avg measurement at those times

cheers
Dave
 
Hi mfb and Dave,
Thank you very much for your replies. Based on your suggestions, I may try Alpha Centauri, when it is highest in the sky.

May I clarify that I am planning to measure stellar aberration, which I believe, is around +/- twenty arc second over the period of an year. My understanding is that the much smaller parallax is superimposed on stellar aberration, but with a 90 deg phase shift. Also, parallax will depend on the distance to the star being measured, whereas stellar aberration, arises solely due to the motion of the observer (earth in our case). Unfortunately, one cannot depend on any 'reference stars', as all stars will exhibit stellar aberration to the same degree.

Any suggestions on stable telescope mounting techniques for the long period of measurement needed is appreciated.

Dave, I live in the suburb of Pennant Hills and work in the inner west; is there any place or gathering of professional/ amateur astronomers in Sydney where I can ask for some tips?

Regards,
Joseph
 
Oh, somehow I read parallax. Aberration is a different challenge, the effect is larger but you cannot use other stars as reference, right.
 
  • Like
Likes   Reactions: davenn
mfb said:
Oh, somehow I read parallax. Aberration is a different challenge, the effect is larger but you cannot use other stars as reference, right.

eeekkk ... We both did, mfb :rolleyes:

Apologies Joseph

I might have to read up on that.
I thought stellar aberration was to do with oscillations due to orbiting planets ... apparently that must have another name

http://www.colorado.edu/physics/phys2170/phys2170_fa06/downloads/stellar_aberration.pdf

OK I have some learning to do LOL
jk1956 said:
Dave, I live in the suburb of Pennant Hills and work in the inner west; is there any place or gathering of professional/ amateur astronomers in Sydney where I can ask for some tips?

just up the hill from me in West Ryde :smile:

The ASNSW ( Astronomical Soc of NSW) meet at Macquarie Uni
I am a member but haven't been to a meeting for yonks

http://www.asnsw.com/cheers
Dave
 
Hi Dave and mfb,
No worries.

Dave, thanks; I will check out ASNSW.

Regards,
Joseph
 

Similar threads

Graduate Measurement of c using Bradley and 1905 SRT aberration models
  • · Replies 14 ·
Replies
14
Views
5K
Undergrad How Can We Measure Properties of Distant Planets and Stars?
  • · Replies 12 ·
Replies
12
Views
3K
Graduate On the Origin of Solar and Stellar Magnetic Fields
  • · Replies 7 ·
Replies
7
Views
5K
Admissions Could I please get critique on my SOP? (Experimental Biophysics)
  • · Replies 9 ·
Replies
9
Views
2K
Graduate How can I understand 4-point-measurements?
  • · Replies 6 ·
Replies
6
Views
3K
Stargazing What are the limitations of astrophotography and how can they be overcome?
  • · Replies 34 ·
2
Replies
34
Views
14K
Can Camera-Based Image Processing Accurately Measure Furnace Flame Intensity?
  • · Replies 3 ·
Replies
3
Views
4K
Stargazing How can I safely view a solar eclipse?
  • · Replies 1 ·
Replies
1
Views
5K
How Is a Sidereal Day Measured Using Stellar Observations?
  • · Replies 1 ·
Replies
1
Views
5K
Undergrad What Key Issues Should Cosmologists Address in the ΛCDM Model?
  • · Replies 1 ·
Replies
1
Views
3K