1496 Turku

{{Short description|Asteroid}}

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

{{Infobox planet

| minorplanet = yes

| name = 1496 Turku

| background = #D6D6D6

| image = 001496-asteroid shape model (1496) Turku.png

| image_scale =

| caption = Shape of Turku modelled from its lightcurve

| discovery_ref =

| discoverer = Y. Väisälä

| discovery_site = Turku Obs.

| discovered = 22 September 1938

| mpc_name = (1496) Turku

| alt_names = {{mp|1938 SA|1}}{{·}}1928 QN
1928 RE{{·}}1950 EC
1954 MH{{·}}1957 HB

| pronounced =

| named_after = Turku {{small|(Finnish city)}}

| mp_category = main-belt{{·}}{{small|(inner)}}
Flora{{·}}background

| orbit_ref =

| epoch = 4 September 2017 (JD 2458000.5)

| uncertainty = 0

| observation_arc = 88.02 yr (32,148 days)

| aphelion = 2.5631 AU

| perihelion = 1.8490 AU

| semimajor = 2.2060 AU

| eccentricity = 0.1619

| period = 3.28 yr (1,197 days)

| mean_anomaly = 90.547°

| mean_motion = {{Deg2DMS|0.3008|sup=ms}} / day

| inclination = 2.5005°

| asc_node = 294.38°

| arg_peri = 0.9272°

| dimensions = {{val|7.47|0.31}} km
{{val|7.758|0.072}} km
{{val|7.973|0.018}} km
8.19 km {{small|(calculated)}}

| rotation = {{val|6.47|0.01}} h
{{val|6.47375|0.00001}} h

| albedo = {{val|0.1930|0.0196}}
{{val|0.203|0.024}}
0.24 {{small|(assumed)}}
{{val|0.347|0.043}}

| spectral_type = S {{small|(assumed)}}

| abs_magnitude = 12.40{{·}}{{val|12.42|0.25}}{{·}}12.6{{·}}12.9

}}

1496 Turku, provisional designation {{mp|1938 SA|1}}, is a Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered on 22 September 1938, by astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory in Turku, Finland. The asteroid was named for the Finnish city of Turku.

Orbit and classification

Turku is a member of the Flora family ({{small|402}}), a giant asteroid family and the largest family of stony asteroids in the main belt. It is, however, a non-family asteroid from the main belt's background population when applying the Hierarchical Clustering Method to its proper orbital elements.

It orbits the Sun in the inner main-belt at a distance of 1.8–2.6 AU once every 3 years and 3 months (1,197 days). Its orbit has an eccentricity of 0.16 and an inclination of 3° with respect to the ecliptic. The body's observation arc begins with its first identification as {{mp|1928 QN}} at Johannesburg Observatory in August 1928, more than 10 years prior to its official discovery observation at Turku.

Physical characteristics

Turku is an assumed S-type asteroid, which is also the Flora family's overall spectral type.

= Rotation period and poles =

In April 2006, a rotational lightcurve of Turku was obtained from photometric observations by French amateur astronomer Laurent Bernasconi. Lightcurve analysis gave a rotation period of 6.47 hours with a brightness amplitude of 0.51 magnitude, indicative of a non-spherical shape ({{small|U=3-}}).

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database, gave a concurring period of 6.47375 hours, as well as a spin axis of (75.0°, −75.0°) in ecliptic coordinates (λ, β).

= Diameter and albedo =

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Turku measures between 7.47 and 7.973 kilometers in diameter and its surface has an albedo between 0.1930 and 0.347.

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of the Flora family – and calculates a diameter of 8.19 kilometers based on an absolute magnitude of 12.6.

Naming

This minor planet was named after Finnish city of Turku, location of the discovering observatory and home of the discoverer Yrjö Väisälä. In ancient times, Turku was the capital of Finland. The official {{MoMP|1496|naming citation}} was published by the Minor Planet Center in January 1956 ({{small|M.P.C. 1350}}).

References

{{reflist|30em|refs=

{{cite web

|type = 2016-08-23 last obs.

|title = JPL Small-Body Database Browser: 1496 Turku (1938 SA1)

|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001496

|publisher = Jet Propulsion Laboratory

|accessdate = 27 September 2017}}

{{cite book

|title = Dictionary of Minor Planet Names – (1496) Turku

|last = Schmadel | first = Lutz D.

|publisher = Springer Berlin Heidelberg

|page = 119

|date = 2007

|isbn = 978-3-540-00238-3

|doi = 10.1007/978-3-540-29925-7_1497 |chapter = (1496) Turku }}

{{cite web

|title = 1496 Turku (1938 SA1)

|work = Minor Planet Center

|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1496

|accessdate = 27 September 2017}}

{{cite book

|title = Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008)

|chapter = Appendix – Publication Dates of the MPCs

|last = Schmadel |first=Lutz D.

|publisher = Springer Berlin Heidelberg

|page = 221

|isbn = 978-3-642-01964-7

|doi = 10.1007/978-3-642-01965-4}}

{{cite web

|title = Asteroids and comets rotation curves – (1496) Turku

|last = Behrend |first = Raoul

|publisher = Geneva Observatory

|url = http://obswww.unige.ch/~behrend/page4cou.html#001496

|accessdate = 27 September 2017}}

{{cite journal

|display-authors = 6

|first1 = Joseph R. |last1 = Masiero

|first2 = T. |last2 = Grav

|first3 = A. K. |last3 = Mainzer

|first4 = C. R. |last4 = Nugent

|first5 = J. M. |last5 = Bauer

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|date = August 2014

|title = Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M

|journal = The Astrophysical Journal

|volume = 791

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|bibcode = 2014ApJ...791..121M

|doi = 10.1088/0004-637X/791/2/121

|arxiv = 1406.6645

|access-date= 27 September 2017}}

{{cite web

|title = Asteroid 1496 Turku – Proper Elements

|publisher = AstDyS-2, Asteroids – Dynamic Site

|url = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=1496

|access-date= 29 October 2019}}

{{cite web

|title = LCDB Data for (1496) Turku

|publisher = Asteroid Lightcurve Database (LCDB)

|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1496%7CTurku

|accessdate = 27 September 2017}}

{{cite journal

|display-authors = 6

|first1 = Joseph R. |last1 = Masiero

|first2 = A. K. |last2 = Mainzer

|first3 = T. |last3 = Grav

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|first7 = M. S. |last7 = Cabrera

|date = November 2012

|title = Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M

|journal = The Astrophysical Journal Letters

|volume = 759

|issue = 1

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|bibcode = 2012ApJ...759L...8M

|doi = 10.1088/2041-8205/759/1/L8

|arxiv = 1209.5794

|access-date= 27 September 2017}}

{{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

|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}}

{{cite journal

|first1 = J. |last1 = Durech

|first2 = J. |last2 = Hanus

|first3 = D. |last3 = Oszkiewicz

|first4 = R. |last4 = Vanco

|date = March 2016

|title = Asteroid models from the Lowell photometric database

|journal = Astronomy and Astrophysics

|volume = 587

|page = 6

|bibcode = 2016A&A...587A..48D

|doi = 10.1051/0004-6361/201527573

|arxiv = 1601.02909}}

{{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

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|first14 = Jeff S. |last14 = Morgan

|first15 = Paul A. |last15 = Price

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|first17 = Christopher |last17 = Waters

|date = November 2015

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

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

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|arxiv = 1506.00762

|access-date= 27 September 2017}}

}}