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Archive for January 9, 2024

Ephemeris: 01/09/2024 – Betelgeuse, Betelgeuse, nope I’m not saying it again

January 9, 2024 Comments off

Jan 9. This is Ephemeris for Tuesday, January 9th. Today the Sun will be up for 9 hours and 1 minute, setting at 5:20, and it will rise tomorrow at 8:18. The Moon, 2 days before new, will rise at 8:04 tomorrow morning.

The constellation Orion has two first magnitude stars, the most famous of these is Betelgeuse. It is a red supergiant star in Orion’s shoulder. Its name actually means Armpit of the Central One. Betelgeuse is about 500 light years away, and it is many hundreds of thousands of times brighter than the Sun, and it’s thought to be almost as big as the orbit of Jupiter. For all its size it’s only about 20 times the mass of the Sun. Some call it a red-hot vacuum. Betelgeuse has been interesting lately, first dimming for a period of time and now somewhat brighter than normal. Astronomers are wondering what’s going on with it. Betelgeuse is a type of star that will end with the supernova explosion. The question is when. Perhaps sometime in the next 100,000 years.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Orion's named stars
Orion’s named stars. Betelgeuse means “Armpit of the Central One”. Bellatrix means “Female warrior”. The names of the belt stars refer to belt or girdle, Rigel refers to Orion’s foot. Saiph means sword, however Orion’s sword is the line of three stars below the belt stars. In binoculars, there’s more than three stars here. Around the second “star” of the sword is the Great Orion Nebula, barely visible here. Created using Stellarium.
Light Curve Betelgeuse 2017 to 2023
Brightness measurements of Betelgeuse from the AAVSO from 2017 to 2023 showing a big dip around January 2020. Betelgeuse has a normal, approximately 400 day, variability cycle and superimposed on this was the big dip in brightness in January 2020. AAVSO = American Association of Variable Star Observers.
Betelgeuse before and after dimming
This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed. Credit: European Southern Observatory (ESO)/M. Montargès et al.
Categories: Ephemeris Program, Observing, Variable Star Tags: ,