View source for OGLE-2012-BLG-0950Lb

{{Short description|Sub-Saturn exoplanet 8,500 light years away}}
'''OGLE-2012-BLG-0950Lb''' is a sub-Saturn ([[super-Neptune]])-type planet {{Convert|2600|pc|ly}} away with 39<ref name=":0">{{Cite web |last=Bartelspublished |first=Meghan |date=2019-01-12 |title='Sub-Saturns' May Force Scientists to Revise Idea of How Planets Form |url=https://www.space.com/42958-sub-saturn-exoplanets-are-common-after-all.html |access-date=2023-12-12 |website=Space.com |language=en}}</ref> or 35<ref>{{Cite web |title=OGLE-2012-BLG-0950L {{!}} NASA Exoplanet Archive |url=https://kvmexoweb.ipac.caltech.edu/overview/OGLE-2012-BLG-0950L%20b#planet_OGLE-2012-BLG-0950L-b_collapsible |access-date=2023-12-12 |website=kvmexoweb.ipac.caltech.edu}}</ref> Earth masses. This type of planet was once thought to be extremely rare because of [[Accretion (astrophysics)|runaway gas accretion]], which would create a gap between 4 and 8 Earth radii or 20 and 80 Earth masses, peaking around 32-64 Earth masses.<ref>{{Cite journal |last=Russell |first=David G. |date=2024-01-01 |title=A sub-Saturn mass-radius desert for planets with equilibrium temperature |url=https://www.sciencedirect.com/science/article/pii/S0019103523003767 |journal=Icarus |volume=407 |pages=115798 |doi=10.1016/j.icarus.2023.115798 |arxiv=2307.05836 |s2cid=259837216 |issn=0019-1035}}</ref> The planet is 2.6 AU from its star.<ref name=":0" /><ref name=":1">{{Cite web |title=Exoplanet-catalog |url=https://exoplanets.nasa.gov/exoplanet-catalog/3406/ogle-2012-blg-0950l-b/ |access-date=2023-12-12 |website=Exoplanet Exploration: Planets Beyond our Solar System |language=en}}</ref> It is likely near-impossible to know much else about the planet's properties (or its star's) because it was detected by [[gravitational microlensing]].<ref name=":1" /> The mass of the host star is approximately 0.56 solar masses (consistent with an [[Red dwarf|M0-0.5V-type star]]).<ref name=":2">{{Cite journal |last1=Koshimoto |first1=N. |last2=Udalski |first2=A. |last3=Beaulieu |first3=J. P. |last4=Sumi |first4=T. |last5=Bennett |first5=D. P. |last6=Bond |first6=I. A. |last7=Rattenbury |first7=N. |last8=Fukui |first8=A. |last9=Bhattacharya |first9=A. |last10=Suzuki |first10=D. |date=2016-12-14 |title=OGLE-2012-bLG-0950Lb: the First Planet Mass Measurement From Only Microlens Parallax and Lens Flux |url=https://ntrs.nasa.gov/citations/20170003332 |journal=The Astronomical Journal |language=en |volume=153 |issue=1 |page=1 |doi=10.3847/1538-3881/153/1/1 |issn=0004-6256 |doi-access=free |arxiv=1607.03267 }}</ref> This exoplanet was the first to have its mass found out using only microlens [[parallax]] and lens flux.<ref name=":2" />

According to microlensing and [[Kepler space telescope|''Kepler'']] data, analogues to this world should be common, showing that our [[Solar System]] is not necessarily a perfect model for [[Nebular hypothesis|planetary formation]] and the runaway gas accretion model may be incorrect or incomplete. This has implications for [[Planetary habitability|habitability]] because gas/ice giants like [[Jupiter]] and [[Neptune]] greatly influenced the Earth's water content (see [[Grand tack hypothesis|Grand Tack hypothesis]]).<ref>{{Cite journal |last1=Suzuki |first1=Daisuke |last2=Bennett |first2=David P. |last3=Ida |first3=Shigeru |last4=Mordasini |first4=Christoph |last5=Bhattacharya |first5=Aparna |last6=Bond |first6=Ian A. |last7=Donachie |first7=Martin |last8=Fukui |first8=Akihiko |last9=Hirao |first9=Yuki |last10=Koshimoto |first10=Naoki |last11=Miyazaki |first11=Shota |last12=Nagakane |first12=Masayuki |last13=Ranc |first13=Clément |last14=Rattenbury |first14=Nicholas J. |last15=Sumi |first15=Takahiro |date=2018-12-19 |title=Microlensing Results Challenge the Core Accretion Runaway Growth Scenario for Gas Giants |journal=The Astrophysical Journal |volume=869 |issue=2 |pages=L34 |doi=10.3847/2041-8213/aaf577 |arxiv=1812.11785 |bibcode=2018ApJ...869L..34S |issn=2041-8213 |doi-access=free }}</ref>

== Composition ==
Sub-Saturns have a wide range of makeups, from puffy planets to large-core worlds.<ref>{{Cite journal |title=Four Sub-Saturns with Dissimilar Densities: Windows into Planetary Cores and Envelopes |doi=10.3847/1538-3881/aa5ea5 |doi-access=free |date=2017 |last1=Petigura |first1=Erik A. |last2=Sinukoff |first2=Evan |last3=Lopez |first3=Eric D. |last4=Crossfield |first4=Ian J. M. |last5=Howard |first5=Andrew W. |last6=Brewer |first6=John M. |last7=Fulton |first7=Benjamin J. |last8=Isaacson |first8=Howard T. |last9=Ciardi |first9=David R. |last10=Howell |first10=Steve B. |last11=Everett |first11=Mark E. |last12=Horch |first12=Elliott P. |last13=Hirsch |first13=Lea A. |last14=Weiss |first14=Lauren M. |last15=Schlieder |first15=Joshua E. |journal=The Astronomical Journal |volume=153 |issue=4 |page=142 |arxiv=1702.00013 |bibcode=2017AJ....153..142P }}</ref> With a radius of 6.5 Earth radii (predicted based on mass-radius relationships), the density would be 0.87 (39 Earth masses) or 0.7 g/cm<sup>3</sup> (35 Earth masses), implying a [[Saturn]]-like composition closer to a standard gas giant than an [[ice giant]]. [[Tholin|Tholins]], a building block of life, are very common in these types of planets as well as the universe as a whole and thus may be present here.<ref>{{Cite web |last=Haynes |first=Korey |date=2019-03-18 |title=What are tholins? The mysterious substance that turned Ultima Thule red {{!}} Astronomy.com |url=https://www.astronomy.com/science/what-are-tholins-the-mysterious-substance-that-turned-ultima-thule-red/ |access-date=2023-12-12 |website=Astronomy Magazine |language=en-US}}</ref>

== See also ==
* [[Mini-Neptune]]
* [[Super-Jupiter]]

== References ==
{{reflist}}

{{2016 in space}}

[[Category:Exoplanets discovered in 2016]]
[[Category:Exoplanets detected by microlensing]]