When I asked "Nothing new?" above I was alluding to the fact that the science media currently publish at full load about our Sun's older twin, HIP 102152
, while here nothing was even mentioned...
In terms of mass, temperature and chemical composition, the star HIP 102152 located at ~ 250 ly distance, is the closest match to our Sun ever found! But it’s also almost 4 billion years older
, providing a most revealing glimpse of what might happen to our 4.6-billion-year-old sun as it ages.
While this story has not yet led to direct evidence for EXO planets around HIP 102152, the quest for the existence and properties of possible planets and their comparison with those of our Sun seems most exciting and definitely worth being watched in this new department!
Note that like the Sun, HIP 102152 has relatively low amounts of iron, magnesium and silicon
, elements that tend to make up the bulk of the mass of rocky planets such as Earth. That could be a first (indirect) sign that the newly discovered star hosts planets.
The story about the Lithium content is also very illuminating (statement by lead author TalaWanda Monroe):"The group found that HIP 102152 has very low levels of lithium. This demonstrates clearly for the first time that older solar twins do indeed have less lithium than our own sun or younger solar twins. We can now be certain that stars somehow destroy their lithium as they age, and that the sun's lithium content appears to be normal for its age.”
Anyway, here are a couple of interesting links to original papers (available to everyone):TalaWanda R. Monroe, Jorge Meléndez et al:
Departamento de Astronomia do IAG/USP, Universidade de São Paulo, Rua do Matão 1226, Cidade Universitária, 05508-900 São Paulo, SP, Brasil
HIGH PRECISION ABUNDANCES OF THE OLD SOLAR TWIN HIP 102152: INSIGHTS ON Li DEPLETION FROM THE OLDEST SUN*
ApJ 774 L32, 2013
and free of chargehttp://arxiv.org/abs/arXiv:1308.5744
andJorge Melendez (Universidade de São Paulo)http://arxiv.org/abs/1307.5274v1
The Sun. A typical star in the solar neighborhood?
PS: An image of HIP 102152 (center) from ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin
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