| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 16h 30m 18.05839s[1] |
| Declination | −12° 39′ 45.3212″[1] |
| Apparent magnitude (V) | 10.07[2](10.05 - 10.10)[3] |
| Characteristics | |
| Spectral type | M3.5V[4] |
| U−Bcolor index | +1.20[5] |
| B−Vcolor index | +1.57[2] |
| Variable type | BY Draconis[3] |
| Astrometry | |
| Radial velocity (Rv) | −21.80±0.13[1] km/s |
| Proper motion (μ) | RA: −94.210mas/yr[1] Dec.: −1,183.917mas/yr[1] |
| Parallax (π) | 232.1390±0.0268 mas[1] |
| Distance | 14.050 ± 0.002 ly (4.3078 ± 0.0005 pc) |
| Absolute magnitude (MV) | 11.87[4] |
| Details | |
| Mass | 0.304±0.007[6] M☉ |
| Radius | 0.319±0.007[6] R☉ |
| Luminosity (bolometric) | 0.0110±0.0001[6] L☉ |
| Luminosity (visual, LV) | 0.0015 L☉ |
| Temperature | 3,307+38 −36[6] K |
| Metallicity [Fe/H] | −0.09±0.09[4] dex |
| Rotation | 95 d[4] |
| Other designations | |
| BD−12°4523,G 153-058,GCTP 3746.00,GJ 628,HIP 80824,LHS 419,Vys 164 | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Wolf 1061 (also known asHIP 80824 and V2306 Ophiuchi) is anM-classred dwarf star located about 14.1light-years away in the constellationOphiuchus. It is the36th-closest-known star system to theSun and has a relatively highproper motion of 1.2seconds of arc per year. Wolf 1061 does not have any unusualspectroscopic features.[7]
Wolf 1061 was first cataloged in 1919 by German astronomerMax Wolf when he published a list of dim stars that had high proper motions. Wolf 1061's name originates from this list.[8] A seven years study found no evidence of photometric transits and confirms the radial velocity signals are not due to stellar activity. The habitable zone estimate for the system lies between approximately 0.1 and 0.2 AU from the star.
![A visual band light curve for V2306 Ophiuchi, plotted from ASAS-SN data[9]](/mt/?noimg=&dark=on&url=https%3a%2f%2fwikipedia.org%2fwiki%2fFile%3aV2306OphLightCurve.png)
In December 2015, a team of astronomers from theUniversity of New South Wales announced the discovery of threeplanets orbiting Wolf 1061. The planets were detected by analyzing 10 years of observations of the Wolf 1061 system by theHARPS spectrograph atLa Silla Observatory inChile. The team used archiveradial velocity measurements of the star's spectrum in the HARPS data and, along with 8 years ofphotometry from theAll Sky Automated Survey, discovered two definite planets with orbital periods of around 4.9 and 17.9 days and a very likely third with a period of 67.3 days.[7]
All three planets have masses low enough that they are likely to berocky planets similar to theinner planets of theSolar System although their actual sizes and densities are currently unknown. However, this information could be determined if the planets happen totransit in front of Wolf 1061 when viewed from Earth. Because all three planets orbit close to the star and have short orbital periods, there is a chance that this will occur. The University of New South Wales team estimated the chances of a transit at around 14% for planet b, 6% for planet c, and 3% for planet d.[7]
One of the planets,Wolf 1061c, is asuper-Earth located near the inner edge of the star'shabitable zone, which conservatively extends from 0.11 to 0.21 AU, or at most from 0.09 to 0.23 AU.[2] It is one of the closest known potentially habitable planets to Earth afterProxima b,Ross 128 b, andLuyten b.[11][12] The next planet out, Wolf 1061 d, could be marginally habitable depending on its atmosphere's composition as it orbits just beyond the habitable zone.[7]
In March 2017, another team of astronomers re-analyzed the system using the HARPS spectrograph. They found planets b and c to be quite similar to their originally reported parameters, but found that planet d was more massive and in a larger, more eccentric orbit. The team was also able to find updated parameters for the host star. Their results showed that Wolf 1061 c is slightly smaller, yet closer to the inner edge of the habitable zone.[4]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥1.91 ± 0.25 M🜨 | 0.0375 ± 0.0012 | 4.8869 ± 0.0005 | 0.15+0.13 −0.10 | — | 1.2(estimated) R🜨 |
| c | ≥3.41+0.43 −0.41 M🜨 | 0.0890 ± 0.003 | 17.8719 ± 0.0059 | 0.11+0.10 −0.07 | — | 1.45(estimated) R🜨 |
| d | ≥7.7+1.12 −1.06 M🜨 | 0.470 ± 0.016 | 217.21+0.55 −0.52 | 0.55+0.08 −0.09 | — | 2.2(estimated) R🜨 |
