<p>At the Wikipedia about an aberration, there is the phrase:</p>
<blockquote>
<p><a href="https://en.wikipedia.org/wiki/Aberration_(astronomy)#Secular_aberration" rel="nofollow noreferrer">a recommended galactocentric aberration constant of 5.8 µas/yr</a></p>
</blockquote>
<p>What is the galactocentric aberration? How is it calculated correctly? An attempt to calculate it gives a different value.</p>
<p><a href="https://en.wikipedia.org/wiki/Sun" rel="nofollow noreferrer">Mean distance from Sun to Milky Way core is ~26,660 light-years. Galactic period is <span class="math-container">${\text{2}}{\text{.25}} \ldots 2.50 \cdot 10^8$</span> years. Velocity of the Solar system orbit is ~251 km/s around the center of the Milky Way.</a></p>
<p>At the opposite points of the orbit the difference of <a href="https://en.wikipedia.org/wiki/Gravitational_lens#Explanation_in_terms_of_spacetime_curvature" rel="nofollow noreferrer">the gravitational deflection of light</a> is approximately <span class="math-container">$\Delta\theta = 2\frac{1}{2}\frac{4 \cdot G \cdot M}{R \cdot c^2} \approx 4\frac{v^2}{c^2} \approx 2.8 \cdot 10^{-6}\approx 0.58 \text{ arcsec} $</span>. It is the value about <span class="math-container">$0.005 \text{ µas/yr}$</span>. That is a thousand times less than above written the galactocentric aberration.</p>

CC BY-SA 4.0
2023-01-07T15:50:33.930Z
Of what? What is the context of your question?  I don;t understand what it is about at all. I make the centripetal accelation of the Sun (assuming a circular orbit) $2.4\times 10^{-10}$ m s$^{-2}$.
ProfRob
CC BY-SA 4.0
2023-01-07T16:17:55.047Z
Ok, I have rewritten question and deleted wrong acceleration.
Imyaf
<observational-astronomy><orbit><light><gravitational-lensing><frame-of-reference>
What is the galactocentric aberration?
Imyaf
# What is the galactocentric aberration?

(Asked by: username_0 on 2023-01-07)

At the Wikipedia about an aberration, there is the phrase:

> [a recommended galactocentric aberration constant of 5.8 µas/yr](https://en.wikipedia.org/wiki/Aberration_(astronomy)#Secular_aberration)

What is the galactocentric aberration? How is it calculated correctly? An attempt to calculate it gives a different value.

[Mean distance from Sun to Milky Way core is ~26,660 light-years. Galactic period is ${\text{2}}{\text{.25}} \ldots 2.50 \cdot 10^8$ years. Velocity of the Solar system orbit is ~251 km/s around the center of the Milky Way.](https://en.wikipedia.org/wiki/Sun)

At the opposite points of the orbit the difference of [the gravitational deflection of light](https://en.wikipedia.org/wiki/Gravitational_lens#Explanation_in_terms_of_spacetime_curvature) is approximately $\Delta\theta = 2\frac{1}{2}\frac{4 \cdot G \cdot M}{R \cdot c^2} \approx 4\frac{v^2}{c^2} \approx 2.8 \cdot 10^{-6}\approx 0.58 \text{ arcsec} $. It is the value about $0.005 \text{ µas/yr}$. That is a thousand times less than above written the galactocentric aberration.

**Tags:** observational-astronomy, orbit, light, gravitational-lensing, frame-of-reference

> **Comments:**
> **username_1**: Of what? What is the context of your question?  I don;t understand what it is about at all. I make the centripetal accelation of the Sun (assuming a circular orbit) $2.4\times 10^{-10}$ m s$^{-2}$.  
> **username_0**: Ok, I have rewritten question and deleted wrong acceleration.  

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## 0 answers

