Planetas aislados /
Isolated planetary mass objects in clusters

The bottom of the brown dwarf domain and beyond...

They have received a lot of names: free-floating planets, isolated planetary mass objects, "sub-brown dwarfs", cluster planets... but none of them has reached to be used as a standard. However, everybody knows what we are talking about: objects with masses below the deuterium-burning limit (about 13 Jupiter masses for solar metallicity), found in young open clusters and at distances large enough to be gravitationally unbound to any star of the cluster.

In the list below, we give the name of the object, the optical I and near infrared J magnitudes, the spectral type (from optical spectra) and the mass of the object, inferred from the best fit to theoretical isochrones. Colon (:) in the mass column means that the given value must be understood only as an estimation of the real mass.



Cluster planets in sigma Orionis

Name I (mag) J (mag) Spectral type Mass (MJup)
S Ori 70 25.0 20.3 T6: 3+5-1
S Ori 69 23.9 20.2 T0: 6:
S Ori 68 23.8 20.2 L5.0 6:
S Ori 67 23.4 19.9 L5.0 7:
S Ori 66 23.2 19.8 L3.5 7:
S Ori 65 23.2 19.8 L3.5 7:
S Ori 64 23.1 19.5 - 8:
S Ori 62 23.0 19.4 L2.0 8+2-3
S Ori 60 22.8 19.2 L2.0 8+2-3
S Ori 58 21.9 18.6 L0.0 11+4-4
S Ori 56 21.7 18.4 L0.5-L1.0 11+4-4
S Ori 55 21.3 18.2 M9 12+4-4



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