Table 3.
Data used to determine background limited yield for the top five candidate stars in this work.
Star | Age | Metallicity | ℳL | ℳM | ℳN2 | e | abin | μ | Inner cutoff | Outer cutoff | Observable Jovian |
---|---|---|---|---|---|---|---|---|---|---|---|
(Gyr) | (log(Fe/H)) | (MJ) | (MJ) | (MJ) | (AU) | (AU) | (AU) | chance (%) | |||
α Cen A | 4.3![]() |
0.19 ± 0.017 (1) | 2.53 | 1.17 ( † ) | 2.24 | 0.52 (5) | 23.1 (5) | 0.47 (5) | 1.53 | 2.91 | 1.9 |
α Cen B | 4.3![]() |
0.15 ± 0.015 (1) | 2.53 | 1.17 ( † ) | 2.24 | 0.52 (5) | 23.1 (5) | 0.53 (5) | 1.46 | 2.58 | 1.6 |
Sirius | 0.242 ± 0.015 (2) | −0.071 ± 0 (2), ( * *) | 0.56 | 0.17 | 0.48 | 0.58 (5) | 19.8 (5) | 0.33 (5) | 1.45 | 2.35 | 2.2 |
Procyon | 2.0 ± 0.0 (1) | 0.03 ± 0.0171 | 2.73 | 1.08 | 2.55 | 0.41 (6) | 15.1(6), ( * *) | 0.31 (6) | 1.59 | 2.88 | 1.5 |
Altair | 1.096![]() |
−0.217 ± 0.007(4), ( * *) | 2.08 | 0.93 | 2.08 | – | – | – | 1.77 | 94.8 | 19.0 |
Notes. The distance to the target star and the background limits for METIS for a 1 h exposure in each band are used to find absolute background limits in each band. Using the solar metallicity BEX model, the minimum observable mass in each band is calculated. For the binary systems, the eccentricity, abin, and mass ratio (μ = Mcompanion/(Mtarget + Mcompanion)) are given. The inner cutoff for the target range starts where the occurrence rate table ends (an orbital period of 640 days). The outer cutoff is placed where a binary companion induces instability (acrit) or (in the case of Altair) where the FOV limit for METIS occurs. See Fig. 2 for a visual diagram of these ranges. The chance of an observable Jovian from the minimum mass (which in all cases was in the M band) over the target range is then reported. See Table 2 for sources for the distance and mass. We note that in this table, the minimum required masses are given with the symbol ℳ. The total chance of observing at least one Jovian is 24.6%. ( * )α Cen B’s age is listed as 8 in Ref. 1 of this table but assuming they are coeval we adopt the same age as α Cen A. ( * *)These values and uncertainties were converted from their original units. ( † )These masses required extrapolation of the BEX models but were verified by eye to ensure reliability of the results.
References. (1) Valenti & Fischer (2005); (2) Bond et al. (2017); (3) Lachaume et al. (1999); (4) Peterson et al. (2006); (5) Dvorak et al. (1989); (6) Bond et al. (2015).
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