9084 Achristou

{{Short description|Asteroid}}

{{Use dmy dates|date=October 2019}}

{{Infobox planet

| minorplanet = yes

| name = 9084 Achristou

| background = #D6D6D6

| image =

| image_size =

| caption =

| discovery_ref =

| discovered = 3 February 1995

| discoverer = D. J. Asher

| discovery_site = Siding Spring Obs.

| mpc_name = (9084) Achristou

| alt_names = {{mp|1995 CS|1}}{{·}}{{mp|1980 GV|1}}

| named_after = Apostolos Christou
{{small|(British astronomer)}}

| mp_category = main-belt{{·}}Hungaria

| orbit_ref =

| epoch = 4 September 2017 (JD 2458000.5)

| uncertainty = 0

| observation_arc = 36.64 yr (13,381 days)

| aphelion = 2.0048 AU

| perihelion = 1.7145 AU

| semimajor = 1.8597 AU

| eccentricity = 0.0780

| period = 2.54 yr (926 days)

| mean_anomaly = 206.11°

| mean_motion = {{Deg2DMS|0.3886|sup=ms}} / day

| inclination = 23.098°

| asc_node = 197.54°

| arg_peri = 72.116°

| moid = 0.7794 AU

| dimensions = 1.76 km {{small|(calculated)}}
{{val|1.916|0.367}} km

| rotation = {{val|8.84|0.02}} h{{efn|name=lightcurve-plot-Stephens}}

| albedo = 0.30 {{small|(assumed)}}
{{val|0.333|0.078}}

| spectral_type = E

| abs_magnitude = 15.7{{·}}15.4{{·}}{{val|16.08|0.28}}

}}

9084 Achristou (provisional designation {{mp|1995 CS|1}}) is a stony Hungaria asteroid from the innermost regions of the asteroid belt, about 1.9 kilometers in diameter. It was discovered by British astronomer David J. Asher at Siding Spring Observatory in New South Wales, Australia, on 3 February 1995. The asteroid was named after British planetary astronomer Apostolos Christou.

Orbit and classification

Achristou is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.7–2.0 AU once every 2 years and 6 months (926 days). Its orbit has an eccentricity of 0.08 and an inclination of 23° with respect to the ecliptic. In April 1980, it was first identified as {{mp|1980 GV|1}} at Palomar Observatory, extending the body's observation arc by 15 years prior to its official discovery observation at Siding Spring.

Physical characteristics

Achristou has been characterized as a bright E-type asteroid.

= Rotation period =

In May 2013, a rotational lightcurve of Achristou was obtained from photometric observations by American astronomer Robert Stephens at the Center for Solar System Studies ({{small|U81}}) in California. Lightcurve analysis gave a rotation period of {{val|8.84}} hours with a low brightness variation of 0.09 magnitude ({{small|U=2+}}).{{efn|name=lightcurve-plot-Stephens}}

= Diameter and albedo =

Based on the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Achristou measures 1.9 kilometers in diameter and its surface has an albedo of 0.33, while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 and calculates a diameter of 1.8 kilometers with an absolute magnitude of 15.7.

Naming

This minor planet was named after Apostolos Christou (born 1968), planetary astronomer and programmer at the North Irish Armagh Observatory, after which the minor planet 10502 Armaghobs was named. His field or research include minor planets in co-orbit with Venus, designing near-Earth asteroids missions, the dwarf planet 1 Ceres, meteor impacts on Venus, as well as the irregular satellite families of the outer planets. The official naming citation was published by the Minor Planet Center on 23 May 2005 {{small|(M.P.C. 54173)}}.

Notes

{{notelist|refs=

{{efn|name=lightcurve-plot-Stephens|1=Stephens (2013): [http://www.planetarysciences.org/plots/RDS/9084_ACHRISTOU_2013-04-29.PNG lightcurve plot] of (9084) Achristou with a rotation period {{val|8.84|0.02}} hours with a brightness amplitude of {{val|0.09}} mag. Summary figures at [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9084%7CAchristou Collaborative Asteroid Lightcurve Link (CALL)]}}

}}

References

{{reflist|30em|refs=

{{cite web

|type = 2016-11-26 last obs.

|title = JPL Small-Body Database Browser: 9084 Achristou (1995 CS1)

|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009084

|publisher = Jet Propulsion Laboratory

|access-date = 22 June 2017}}

{{cite book

|title = Dictionary of Minor Planet Names – (9084) Achristou, Addendum to Fifth Edition: 2003–2005

|last = Schmadel | first = Lutz D.

|publisher = Springer Berlin Heidelberg

|page = 42

|date = 2006

|isbn = 978-3-540-34360-8

|doi = 10.1007/978-3-540-34361-5_303 |chapter = (9084) Achristou [1.86, 0.08, 23.1] }}

{{cite web

|title = 9084 Achristou (1995 CS1)

|work = Minor Planet Center

|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=9084

|access-date = 28 April 2016}}

{{cite web

|title = LCDB Data for (9084) Achristou

|publisher = Asteroid Lightcurve Database (LCDB)

|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9084%7CAchristou

|access-date = 28 April 2016}}

{{cite web

|title = MPC/MPO/MPS Archive

|work = Minor Planet Center

|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html

|access-date = 28 April 2016}}

{{cite journal

|display-authors = 6

|first1 = A. |last1 = Mainzer

|first2 = T. |last2 = Grav

|first3 = J. |last3 = Masiero

|first4 = E. |last4 = Hand

|first5 = J. |last5 = Bauer

|first6 = D. |last6 = Tholen

|first7 = R. S. |last7 = McMillan

|first8 = T. |last8 = Spahr

|first9 = R. M. |last9 = Cutri

|first10 = E. |last10 = Wright

|first11 = J. |last11 = Watkins

|first12 = W. |last12 = Mo

|first13 = C. |last13 = Maleszewski

|date = November 2011

|title = NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...90M

|journal = The Astrophysical Journal

|volume = 741

|issue = 2

|page = 25

|bibcode = 2011ApJ...741...90M

|doi = 10.1088/0004-637X/741/2/90

|arxiv = 1109.6407

|s2cid = 118700974 |access-date= 28 April 2016}}

{{Cite journal

|first1 = Robert D. |last1 = Stephens

|first2 = Daniel |last2 = Coley

|first3 = Brian D. |last3 = Warner

|date = January 2014

|title = Collaborative Asteroid Lightcurve Analysis at the Center for Solar System Studies: 2013 April-June

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014MPBu...41....8S

|journal = The Minor Planet Bulletin

|volume = 41

|issue = 1

|pages = 8–13

|issn = 1052-8091

|bibcode = 2014MPBu...41....8S

|access-date= 28 April 2016}}

{{cite journal

|display-authors = 6

|first1 = Peter |last1 = Veres

|first2 = Robert |last2 = Jedicke

|first3 = Alan |last3 = Fitzsimmons

|first4 = Larry |last4 = Denneau

|first5 = Mikael |last5 = Granvik

|first6 = Bryce |last6 = Bolin

|first7 = Serge |last7 = Chastel

|first8 = Richard J. |last8 = Wainscoat

|first9 = William S. |last9 = Burgett

|first10 = Kenneth C. |last10 = Chambers

|first11 = Heather |last11 = Flewelling

|first12 = Nick |last12 = Kaiser

|first13 = Eugen A. |last13 = Magnier

|first14 = Jeff S. |last14 = Morgan

|first15 = Paul A. |last15 = Price

|first16 = John L. |last16 = Tonry

|first17 = Christopher |last17 = Waters

|date = November 2015

|title = Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V

|journal = Icarus

|volume = 261

|pages = 34–47

|bibcode = 2015Icar..261...34V

|doi = 10.1016/j.icarus.2015.08.007

|arxiv = 1506.00762

|s2cid = 53493339 |access-date= 28 April 2016}}

{{cite journal

|display-authors = 6

|first1 = Joseph R. |last1 = Masiero

|first2 = A. K. |last2 = Mainzer

|first3 = T. |last3 = Grav

|first4 = J. M. |last4 = Bauer

|first5 = R. M. |last5 = Cutri

|first6 = J. |last6 = Dailey

|first7 = P. R. M. |last7 = Eisenhardt

|first8 = R. S. |last8 = McMillan

|first9 = T. B. |last9 = Spahr

|first10 = M. F. |last10 = Skrutskie

|first11 = D. |last11 = Tholen

|first12 = R. G. |last12 = Walker

|first13 = E. L. |last13 = Wright

|first14 = E. |last14 = DeBaun

|first15 = D. |last15 = Elsbury

|first16 = T. IV |last16 = Gautier

|first17 = S. |last17 = Gomillion

|first18 = A. |last18 = Wilkins

|date = November 2011

|title = Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M

|journal = The Astrophysical Journal

|volume = 741

|issue = 2

|page = 20

|bibcode = 2011ApJ...741...68M

|doi = 10.1088/0004-637X/741/2/68

|arxiv = 1109.4096

|s2cid = 118745497 |access-date= 4 December 2016}}

}}