BD−17 63

BD−17 63 is a low-mass K type star in the southern constellation Cetus. It is a 9th magnitude star at a distance of about 112 light years from Earth.

BD−17 63
Observation data
Epoch J2000      Equinox J2000
Constellation Cetus
Right ascension  00h 28m 34.3061s[1]
Declination −16° 13′ 34.8414″[1]
Apparent magnitude (V) 9.63
Characteristics
Spectral type K4V[2]
Apparent magnitude (B) ~10.77[2]
Apparent magnitude (J) 7.574 ± 0.019[2]
Apparent magnitude (H) 7.027 ± 0.033[2]
Apparent magnitude (K) 6.914 ± 0.024[2]
Astrometry
Proper motion (μ) RA: −355.181±0.161[1] mas/yr
Dec.: −227.737±0.070[1] mas/yr
Parallax (π)28.9903 ± 0.0774[1] mas
Distance112.5 ± 0.3 ly
(34.49 ± 0.09 pc)
Absolute magnitude (MV)6.87
Details
Mass0.72 ± 0.01[3] M☉
Radius0.7 ± 0.01[3] R☉
Luminosity0.212 ± 0.001[3] L☉
Surface gravity (log g)4.6 ± 0.01[3] cgs
Temperature4692 ± 9[3] K
Metallicity [Fe/H]–0.03 ± 0.06 dex
Age10.5 ± 2.6[3] Gyr
Other designations
Felixvarela, 2MASS J00283433-1613343, SAO 147293, HIP 2247, PPM 208851
Database references
SIMBADdata
Exoplanet Archivedata
Extrasolar Planets
Encyclopaedia		data

The star BD-17 63 is named Felixvarela. The name was selected in the NameExoWorlds campaign by Cuba, during the 100th anniversary of the IAU. Felix Varela (1788–1853) was the first to teach science in Cuba.[4][5]

Planetary system

In October 2008 an extrasolar planet, BD−17 63 b, was reported to be orbiting this star. This object was detected using the radial velocity method by search programs conducted using the HARPS spectrograph.[6]

The BD−17 63 planetary system[6]
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(days)		 Eccentricity Inclination Radius
b ≥5.1 ± 0.12 MJ 1.34 ± 0.02 655.6 ± 0.6 0.54 ± 0.005 — —
gollark: I mean, what do you expect to happen if you do something unsupported and which creates increasingly large problems each time you do it?
gollark: <@151391317740486657> Do you know what "unsupported" means? PotatOS is not designed to be used this way.
gollark: Specifically, 22 bytes for the private key and 21 for the public key on ccecc.py and 25 and 32 on the actual ingame one.
gollark: <@!206233133228490752> Sorry to bother you, but keypairs generated by `ccecc.py` and the ECC library in use in potatOS appear to have different-length private and public keys, which is a problem.EDIT: okay, apparently it's because I've been accidentally using a *different* ECC thing from SMT or something, and it has these parameters instead:```---- Elliptic Curve Arithmetic---- About the Curve Itself-- Field Size: 192 bits-- Field Modulus (p): 65533 * 2^176 + 3-- Equation: x^2 + y^2 = 1 + 108 * x^2 * y^2-- Parameters: Edwards Curve with c = 1, and d = 108-- Curve Order (n): 4 * 1569203598118192102418711808268118358122924911136798015831-- Cofactor (h): 4-- Generator Order (q): 1569203598118192102418711808268118358122924911136798015831---- About the Curve's Security-- Current best attack security: 94.822 bits (Pollard's Rho)-- Rho Security: log2(0.884 * sqrt(q)) = 94.822-- Transfer Security? Yes: p ~= q; k > 20-- Field Discriminant Security? Yes: t = 67602300638727286331433024168; s = 2^2; |D| = 5134296629560551493299993292204775496868940529592107064435 > 2^100-- Rigidity? A little, the parameters are somewhat small.-- XZ/YZ Ladder Security? No: Single coordinate ladders are insecure, so they can't be used.-- Small Subgroup Security? Yes: Secret keys are calculated modulo 4q.-- Invalid Curve Security? Yes: Any point to be multiplied is checked beforehand.-- Invalid Curve Twist Security? No: The curve is not protected against single coordinate ladder attacks, so don't use them.-- Completeness? Yes: The curve is an Edwards Curve with non-square d and square a, so the curve is complete.-- Indistinguishability? No: The curve does not support indistinguishability maps.```so I might just have to ship *two* versions to keep compatibility with old signatures.
gollark: > 2. precompilation to lua bytecode and compressionThis was considered, but the furthest I went was having some programs compressed on disk.

See also
  • List of extrasolar planets

References
  1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. "SIMBAD query result: G 158-84 -- High proper-motion Star". Centre de Données astronomiques de Strasbourg. Retrieved 2009-06-11.
  3. Bonfanti, A.; et al. (2015). "Revising the ages of planet-hosting stars". Astronomy and Astrophysics. 575. A18. arXiv:1411.4302. Bibcode:2015A&A...575A..18B. doi:10.1051/0004-6361/201424951.
  4. "Approved names". NameExoworlds. Retrieved 2020-01-02.
  5. "International Astronomical Union | IAU". www.iau.org. Retrieved 2020-01-02.
  6. Moutou, C.; et al. (2009). "The HARPS search for southern extra-solar planets XVII. Six long-period giant planets around BD -17 0063, HD 20868, HD 73267, HD 131664, HD 145377, HD 153950". Astronomy and Astrophysics. 496 (2): 513–519. arXiv:0810.4662. Bibcode:2009A&A...496..513M. doi:10.1051/0004-6361:200810941.


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