HD 171028

{{Starbox observe

| epoch = J2000.0

| constell = Ophiuchus

| ra = {{RA|18|32|15.4933}}

| dec = {{DEC|+06|56|44.6858}}

| appmag_v = 8.301

}}

{{Starbox character

| type =

| class = G0

| b-v = 0.61

| u-b =

| variable =

}}

{{Starbox astrometry

| radial_v = {{val|+13.48|0.28}}

| prop_mo_ra = {{val|−42.869|0.084}}

| prop_mo_dec = {{val|−14.705|0.077}}

| parallax = 8.9274

| p_error = 0.0497

| parallax_footnote =

| absmag_v =

}}

{{Starbox detail

| source =

| mass = {{val|1.01|0.06}}

| radius = {{val|2.42|0.01|0.03}}

| luminosity = {{val|5.406|0.042|0.041}}

| gravity = {{val|3.84|0.03}}

| temperature = {{val|5671|16|fmt=commas}}

| metal_fe = {{val|−0.48|0.01}}

| rotational_velocity = 2.3

| age_gyr = {{val|4.890|0.229}}

}}

{{Starbox catalog

| names = {{odlist | 2MASS=J18321548+0656446 | BD=+06 3833 | TYC=458-1450-1 }}

}}

{{Starbox reference

| Simbad = HD+171028

}}

HD 171028 is a star with an exoplanet companion in the equatorial constellation of Ophiuchus. With an apparent visual magnitude of 8.3, it is too faint to be readily visible with the naked eye. Unlike most planet-harboring stars, it does not have a Hipparcos number. The star is located at a distance of approximately 365 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +13.5 km/s.

This is a yellow-hued G-type star of unknown luminosity class with a stellar classification of G0. It is a metal-poor star belonging to the thin disk population. HD 171028 is estimated to be nearly five billion years old and is spinning with a projected rotational velocity of 2.3 km/s. It has the same mass as the Sun, but the radius is 2.4 times larger. The star is radiating 5.4 times the luminosity of the Sun from its photosphere at an effective temperature of 5,671 K.

In the summer of 2007, a Jovian planetary companion was discovered by the HARPS planet search program using the radial velocity method. This object is orbiting at a distance of {{val|1.32|ul=AU}} from the host star with a period of {{convert|550|days|years|disp=out|abbr=off}} and an eccentricity (ovalness) of 0.59. Since the inclination of the orbit is unknown, only a minimum mass can be determined. This planet has at least double the mass of Jupiter.

{{OrbitboxPlanet begin

| table_ref =

}}

{{OrbitboxPlanet

| exoplanet = b

| mass = {{val|1.98|p=≥}}

| semimajor = 1.32

| period = {{val|550|3}}

| eccentricity = {{val|0.59|0.01}}

}}

References

{{Reflist|refs=

{{cite journal

| title=The HARPS search for southern extra-solar planets. XII. A giant planet orbiting the metal-poor star HD 171028

| url=https://www.aanda.org/articles/aa/full/2007/41/aa8129-07/aa8129-07.html

| last1=Santos | first1=N. C. | last2=Mayor | first2=M.

| last3=Bouchy | first3=F. | last4=Pepe | first4=F.

| last5=Queloz | first5=D. | last6=Udry | first6=S.

| display-authors=1 | journal=Astronomy and Astrophysics

| volume=474 | issue=2 | pages=647–651 | year=2007

| arxiv=0708.0954 | bibcode=2007A&A...474..647S

| doi=10.1051/0004-6361:20078129 | s2cid=73681862 }}

{{citation

| title=The HARPS search for southern extrasolar planets XXV. Results from the metal-poor sample |year=2011

| display-authors=1 | last1=Santos |first1=Nuno C.

|last2=Mayor |first2=Michel |last3=Bonfils |first3=Xavier

|last4=Dumusque |first4=Xavier |last5=Bouchy |first5=François

|last6=Figueira |first6=Pedro |last7=Lovis |first7=Christophe

|last8=Melo |first8=Claudio |last9=Pepe |first9=Francesco

|last10=Queloz |first10=Didier |last11=Ségransan |first11=Damien

|last12=Sousa |first12=Sérgio Gonçalves |last13=Udry |first13=Stéphane

| journal=Astronomy and Astrophysics

| volume=526 |pages=A112

| doi=10.1051/0004-6361/201015494 |arxiv=1011.2094

| bibcode=2011A&A...526A.112S |s2cid=119106340

| url=https://www.aanda.org/articles/aa/full_html/2011/02/aa15494-10/aa15494-10.html }}

{{cite journal

| title=Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur

| display-authors=1 | last1=Costa Silva | first1=A. R.

| last2=Delgado Mena | first2=E. | last3=Tsantaki | first3=M.

| journal=Astronomy & Astrophysics

| volume=634 | id=A136 | pages=10 | date=February 2020

| doi=10.1051/0004-6361/201936523 | arxiv=1912.08659

| bibcode=2020A&A...634A.136C | s2cid=209405391 }}

{{cite journal

| title=Spectroscopic characterization of a sample of metal-poor solar-type stars from the HARPS planet search program. Precise spectroscopic parameters and mass estimation

| display-authors=1 | journal=Astronomy and Astrophysics

| volume=526 | id=A99 | pages=11 | date=February 2011

| doi=10.1051/0004-6361/201015646 | arxiv=1012.1528

| bibcode=2011A&A...526A..99S | s2cid=118785170 }}

{{cite journal

| title=A peculiarity of metal-poor stars with planets?

| last=Haywood | first=M.

| journal=Astronomy and Astrophysics

| volume=482 | issue=2 | pages=673–676 | date=May 2008

| doi=10.1051/0004-6361:20079141 | arxiv=0804.2954

| bibcode=2008A&A...482..673H | s2cid=16390388 }}

}}