[ExI] [Extropolis] Fusion News

[BillK]

On Tue, 18 Feb 2025 at 06:54, Keith Henson via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

> I was firmly in the "we are alone" camp and believed the bizarre light
> dips of Tabby's star had to have a natural explanation.
>
> Until the astronomers found that Tabby's star was in the middle of a
> cluster of blinking stars about 1000 lightyears across.  The nearest
> blinker is 511 lightyears from us.
>
> So I ran the numbers for the shadow we see in the data.  We may be
> seeing something short of a K2.
>
> It looks like they are using a huge structure to hold power and
> radiating equipment.  This way you get a maximum speed of light delay
> between the computing elements.
> <snip>
>
> I hope someone has a better explanation for the 24-blinking stars
> because we don't need the competition.
>
> Keith
> _______________________________________________
>


I asked the new Grok-3 AI to review the Schmidt paper of stars similar to
Tabby's star.
Grok points out that there is no evidence that these 21 stars are located
near to Tabby's star.
BillK

Question -
Are any of the stars in this paper similar to Tabby's star or near to
Tabby's star? https://iopscience.iop.org/article/10.3847/2041-8213/ab2e77

Grok-3
The paper you referenced, published in *The Astrophysical Journal Letters*
(ApJL, 873:L7, 2019), titled "A Search for Analogs of KIC 8462852
(Boyajian’s Star): A Second List of Candidates from the TESS Mission" by
Edward G. Schmidt, investigates stars observed by the Transiting Exoplanet
Survey Satellite (TESS) that exhibit unusual dimming patterns similar to
those observed in KIC 8462852, also known as Tabby's Star or Boyajian’s
Star. Tabby's Star is famous for its irregular and significant dips in
brightness, which have been hypothesized to be caused by dust, comets, or
even exotic explanations like alien megastructures.

### Key Points from the Paper:
1. **Objective**: The study aimed to identify stars with light curves
similar to Tabby's Star, focusing on TESS data from sectors 1–13. It builds
on previous searches for analogs of Tabby's Star using Kepler and other
datasets.
2. **Methodology**: The author searched for stars exhibiting irregular,
non-periodic dimming events, similar to the hallmark features of Tabby's
Star. The light curves were analyzed for large, asymmetric dips in
brightness.
3. **Results**: The paper identifies a list of candidate stars that show
similar dimming behavior to Tabby's Star. These candidates are not
necessarily near Tabby's Star in physical space but are similar in their
photometric behavior (i.e., their light curves).

### Are Any Stars Similar to Tabby's Star?
Yes, the stars identified in the paper are considered analogs of Tabby's
Star because they exhibit similar irregular dimming patterns. However,
"similarity" here refers to the light curve behavior, not physical
proximity or shared physical characteristics like temperature, size, or
spectral type. The candidates listed in the paper (e.g., in Table 1) are
stars observed by TESS that show unusual dips in brightness, potentially
caused by similar mechanisms as those hypothesized for Tabby's Star (e.g.,
dust clouds, cometary fragments, or other obscuring material).

### Are Any Stars Near Tabby's Star?
The paper does not focus on the physical proximity of the candidate stars
to Tabby's Star. Instead, it focuses on stars observed by TESS across
different sectors of the sky. Tabby's Star is located in the constellation
Cygnus, at a distance of approximately 1,470 light-years from Earth. The
TESS candidates are distributed across the sky, and their distances from
Earth (and from Tabby's Star) vary widely. The paper does not provide
specific information about the spatial proximity of these stars to Tabby's
Star, as the primary criterion for selection was the similarity in light
curve behavior, not location.

To determine if any of the candidate stars are physically near Tabby's
Star, you would need to:
1. Cross-reference the coordinates (RA and Dec) of the candidates (provided
in the paper) with the coordinates of Tabby's Star (RA ≈ 20h 06m 15.46s,
Dec ≈ +44° 27' 24.8").
2. Calculate the 3D separation using their distances, which would require
additional data (e.g., parallaxes from Gaia DR3) to estimate their
distances from Earth.
3. Assess whether the stars are close enough to be considered "near"
Tabby's Star (e.g., within a few light-years, which is unlikely given the
distances involved).

### Summary:
- **Similarity to Tabby's Star**: Yes, the stars in the paper are similar
to Tabby's Star in terms of their light curve behavior (irregular dimming).
These are photometric analogs, not necessarily physical analogs.
- **Proximity to Tabby's Star**: The paper does not address physical
proximity. The candidate stars are distributed across the sky and are
unlikely to be near Tabby's Star in 3D space, as TESS observes stars in
different regions of the sky, and distances between stars are typically
large.

If you are specifically interested in stars near Tabby's Star, you would
need to perform additional analysis using the coordinates and distances of
the candidates, which may require consulting other catalogs like Gaia for
precise astrometry. However, the primary focus of this paper is on
identifying stars with similar dimming patterns, not on their spatial
relationships.
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