Theta Eridani was much brighter for early astronomers

[mfb]

TL;DR

Theta Eridani is magnitude 2.9 today, hardly remarkable. Multiple ancient astronomers described it as one of the brightest stars. Recent research found a possible explanation of the discrepancy.

Hipparchus (129 BC), Ptolemy (137 AD) and al-Sufi (964) all described Theta Eridani as one of the brightest stars in the sky. Today it is still visible to the naked eye but unremarkable at magnitude 2.9. A new publication explains the larger historic brightness as mass transfer between two stars in the system, leading to a temporary brightness increase for something like 1000 years:
The forgotten bright star: Theta Eridani as a millenary stellar transient observed by Hipparchus, Ptolemy and al-Sufi
Article discussing the publication

This shows the long-term value of surveys - even if they were done with the naked eye! Many interesting effects only show up if you can compare systems at different times.

 

[sbrothy]

So this could in fact be related to the Nebra disk?

Thread 'Bronze Age or Iron Age? Age of Nebra Sky Disk is disputed'

Jan 19, 2021

The age of the Nebra (from Germany) Sky Disk (claimed to be the oldest known representation of the heavens) is in dispute.
It was found in the black market, so provenance is unclear.
NY Times article here.

• BillTre
• Age Disk Iron Sky
• Replies: 3
• Forum: Art, History, and Linguistics

• 

High School Thread 'Popular physics - The Nebra disk'

Aug 17, 2020

Popular Physics.

"Evidences of the earliest Supernova observation in the Nebra disk
R.G. Pizzone"

---- https://arxiv.org/abs/2005.07411I know this isn't exactly breaking news and I cannot comment of the quality or validity of the research, but I've found that due to the brevity of the paper and it's pedagoical execution it has a tendency to draw in an audience not normally interested in astronomy.

And with that I mean barely literate people who nevertheless enjoy the drawings and continuity of the religious awe of the event.

It may have been a little overlooked...

• sbrothy
• Disk Physics
• Replies: 5
• Forum: Astronomy, Astrophysics, Cosmology

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Ah, the good old days when I received a finger-rapping on an almost daily basis with a slide-rule from V50!

EDIT: I must've meant 50. Although I'm confused now.