161 Athor

{{Short description|Main-belt asteroid}}

{{Use dmy dates|date=September 2018}}

{{Infobox planet

| minorplanet = yes

| background = #D6D6D6

| apsis =

| name = 161 Athor

| image = 161Athor (Lightcurve Inversion).png

| image_scale =

| caption = A three-dimensional model of 161 Athor based on its light curve.

| symbol =

| discovery_ref = {{cite web |url=http://www.cfa.harvard.edu/iau/lists/NumberedMPs000001.html |title=Discovery Circumstances: Numbered Minor Planets (1)-(5000) |accessdate=December 20, 2008 |publisher=IAU: Minor Planet Center |archiveurl=https://web.archive.org/web/20090202185140/http://www.cfa.harvard.edu/iau/lists/NumberedMPs000001.html |archivedate= February 2, 2009 }}

| discoverer=James Craig Watson

| discovery_site=Detroit Observatory

| discovered=19 April 1876

| mpc_name=(161) Athor

| alt_names=A876 HA; 1899 TA;
1961 PF; {{mp|1973 YN|4}}

| pronounced={{IPAc-en|'|æ|θ|ər}},Noah Webster (1884) A Practical Dictionary of the English Language {{IPAc-en|'|ɑː|θ|ər}}{{OED|Hathor, Athor}}

| named_after=Hathor

| mp_category=Main belt{{Cite web |url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=161 |archive-url=https://web.archive.org/web/20200820123100/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=161;cad=1 |url-status=live |archive-date=20 August 2020 |title=161 Athor |work=JPL Small-Body Database |publisher=NASA/Jet Propulsion Laboratory |access-date=12 May 2016}}

| orbit_ref={{cite web |url=https://newton.spacedys.com/astdys/index.php?pc=1.1.0&n=161 |title=(161) Athor |accessdate=December 20, 2008 |work=AstDyS |publisher=University of Pisa |location=Italy }}

| epoch=31 July 2016 (JD 2457600.5)

| aphelion={{Convert|2.70593|AU|Gm|abbr=on|lk=on}}

| perihelion={{Convert|2.05285|AU|Gm|abbr=on}}

| time_periastron=2024-Jan-13

| semimajor={{Convert|2.37939|AU|Gm|abbr=on}}

| eccentricity=0.137237

| period=3.67 yr (1340.6 d)

| avg_speed=

| inclination=9.05986°

| asc_node=18.6090°

| mean_anomaly=348.807°

| arg_peri=295.007°

| satellites=

| dimensions={{val|44.19|3.3|ul=km}}
Mean diameter
{{val|47.0|0.2|u=km}}
circular fit{{cite web |url=http://www.psi.edu/pds/resource/occ.html |author=Dunham |author2=Herald |name-list-style=amp |title=Asteroid Occultations |accessdate=December 27, 2008 |work=EAR-A-3-RDR-OCCULTATIONS-V6.0 |publisher=Planetary Data System |date=2008 }}{{cbignore|bot=medic}}

| mass =

| density =

| rotation = {{Convert|7.280|h|d|abbr=on|lk=on}}
7.281 ± 0.001 hours{{cite journal | bibcode=2008MPBu...35..147P | author=Pilcher | author2=Higgins | name-list-style=amp | title=Period Determination for 161 Athor | journal=The Minor Planet Bulletin | volume=35 | issue=4 | page=147 | date=2008 }}
7.288 ± 0.007 hours{{cite journal | bibcode=1980A&AS...42...85D | author=Debehogne | author2=Zappala | name-list-style=amp | title=Photoelectric lightcurves of the asteroids 139 Juewa and 161 Athor, obtained with the 50 CM photometric telescope at ESO, La Silla | journal=Astronomy and Astrophysics Supplement Series | volume=42 | pages=85–89 | date=1980 }}

| axial_tilt =

| pole_ecliptic_lat =

| pole_ecliptic_lon =

| albedo = {{val|0.1980|0.033}}{{cite web|url=http://www.psi.edu/pds/resource/imps.html |author=Tedesco |title=Supplemental IRAS Minor Planet Survey (SIMPS) |accessdate=December 27, 2008 |work=IRAS-A-FPA-3-RDR-IMPS-V6.0 |publisher=Planetary Data System |date=2004 |archiveurl=https://web.archive.org/web/20090817051318/http://www.psi.edu/pds/resource/imps.html |archivedate=August 17, 2009 |url-status=dead |display-authors=etal |df=mdy }}

| spectral_type = M{{cite web|url=http://www.psi.edu/pds/resource/taxonomy.html |author=Neese |title=Asteroid Taxonomy |accessdate=December 27, 2008 |work=EAR-A-5-DDR-TAXONOMY-V5.0 |publisher=Planetary Data System |date=2005 |archiveurl=https://web.archive.org/web/20090805185511/http://www.psi.edu/pds/resource/taxonomy.html |archivedate=August 5, 2009 |url-status=dead |df=mdy }}

| abs_magnitude = 9.15{{cite web|url=http://www.psi.edu/pds/resource/astermag.html |author=Tholen |title=Asteroid Absolute Magnitudes |accessdate=December 27, 2008 |work=EAR-A-5-DDR-ASTERMAG-V11.0. |publisher=Planetary Data System |date=2007 |archiveurl=https://web.archive.org/web/20090816200758/http://www.psi.edu/pds/resource/astermag.html |archivedate=August 16, 2009 |url-status=dead |df=mdy }}

| mean_motion = {{Deg2DMS|0.268538|sup=ms}} / day

| observation_arc = 116.50 yr (42551 d)

| uncertainty = 0

}}

161 Athor is an M-type Main belt asteroid that was discovered by James Craig Watson on April 19, 1876, at the Detroit Observatory and named after Hathor, an Egyptian fertility goddess. It is the namesake of a proposed Athor asteroid family, estimated to be ~3 billion years old.

Photometric observations of the minor planet in 2010 gave a rotation period of {{Val|7.2798|0.0001|u=h}} with an amplitude of {{Val|0.19|0.02}} in magnitude. This result is consistent with previous determinations. An occultation by Athor was observed, on October 15, 2002, showing an estimated diameter of {{convert|47.0|km}}. The spectra is similar to that of carbonaceous chondrites, with characteristics of ferric oxides and little or no hydrated minerals.