{{Short description|Asteroid}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1575 Winifred | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = <ref name="jpldata" /> | discovered = 20 April 1950 | discoverer = Indiana University<br />{{nowrap|{{small|(Indiana Asteroid Program)}}}} | discovery_site = Goethe Link Obs. | mpc_name = (1575) Winifred | alt_names = 1950 HH{{·}}1928 HG<br />1939 GK{{·}}{{mp|1950 HD|1}}<br />{{mp|1977 UH|1}} | named_after = Winifred Sawtell<br />{{small|(staff member at USNO)}}<ref name="springer" /> | mp_category = main-belt{{·}}Phocaea<ref name="lcdb" /><ref name="Ferret" /> | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 88.51 yr (32,327 days) | aphelion = 2.7990 AU | perihelion = 1.9497 AU | semimajor = 2.3743 AU | eccentricity = 0.1789 | period = 3.66 yr (1,336 days) | mean_anomaly = 158.55° | mean_motion = {{Deg2DMS|0.2694|sup=ms}} / day | inclination = 24.827° | asc_node = 206.84° | arg_peri = 348.40° | dimensions = {{val|9.31|1.0}} km {{small|(IRAS)}}<ref name="SIMPS" /><br />{{val|9.441|0.131}} km<ref name="WISE" /><br />9.45 km {{small|(derived)}}<ref name="lcdb" /><br />{{val|9.488|0.254}}<ref name="Masiero-2011" /><br />{{val|10.66|0.43}} km<ref name="Masiero-2012" /> | rotation = {{val|125|2}} h<ref name="Warner-2010a" /><br />{{val|129}} h<ref name="geneva-obs" /> | albedo = {{val|0.236|0.033}}<ref name="Masiero-2011" /><br />{{val|0.2388|0.0311}}<ref name="WISE" /><br />{{val|0.2452|0.064}}<ref name="SIMPS" /><br />{{val|0.247|0.034}}<ref name="Masiero-2012" /><br />0.3134 {{small|(derived)}}<ref name="lcdb" /> | spectral_type = S<ref name="lcdb" /> | abs_magnitude = {{val|11.36|1.19}}<ref name="Veres-2015" />{{·}}12.0<ref name="jpldata" /><ref name="lcdb" /><ref name="Masiero-2012" />{{·}}12.3<ref name="WISE" /> }}
'''1575 Winifred''', provisional designation {{mp|1950 HH}}, is a stony Phocaea asteroid and slow rotator from the inner regions of the asteroid belt, approximately 9.5 kilometers in diameter.
It was discovered on 20 April 1950, by astronomer Robert Curry Cameron of Indiana University during the Indiana Asteroid Program at Goethe Link Observatory in Indiana, United States.<ref name="MPC-Winifred" /> It was named after Winifred Cameron, an astronomer at the United States Naval Observatory.<ref name="springer" />
== Orbit and classification ==
The stony S-type asteroid is a member of the Phocaea family ({{small|701}}), a group of asteroids with similar orbital characteristics, named after the family's namesake 25 Phocaea.<ref name="Ferret" /> It orbits the Sun at a distance of 1.9–2.8 AU once every 3 years and 8 months (1,336 days). Its orbit has an eccentricity of 0.18 and an inclination of 25° with respect to the ecliptic.<ref name="jpldata" />
''Winifred'' was first identified as {{mp|1928 HG}} at Johannesburg Observatory in 1928, extending the body's observation arc by 22 years prior to its official discovery observation.<ref name="MPC-Winifred" />
== Physical characteristics ==
=== Rotational lightcurve ===
In July 2009, a rotational lightcurve was obtained for this asteroid from photometric observations taken by American astronomer Brian D. Warner at his Palmer Divide Observatory in Colorado. It gave a well-defined rotation period of {{val|125|2}} hours with an exceptionally high brightness amplitude of {{val|1.20}} in magnitude ({{small|U=3}}), and no sign of a non-principal axis rotation (NPAR).<ref name="Warner-2010a" /> The result supersedes a previous observation by French astronomer Laurent Bernasconi from May 2005, that gave a similar, yet less accurate period of 129 hours, and with a smaller amplitude of 0.51 in magnitude ({{small|U=1}}).<ref name="geneva-obs" />
=== Diameter and albedo ===
According to the surveys carried out by the Infrared Astronomical Satellite, IRAS, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, ''Winifred'' has an albedo of 0.24 to 0.25 and a diameter between 9.3 and 10.7 kilometers,<ref name="SIMPS" /><ref name="WISE" /><ref name="Masiero-2011" /><ref name="Masiero-2012" /> while the ''Collaborative Asteroid Lightcurve Link'' derives a higher albedo of 0.31 and a diameter of 9.5 kilometers with an absolute magnitude of 12.0.<ref name="lcdb" />
== Naming ==
This minor planet was named for a staff member of the United States Naval Observatory in Washington D.C., Winifred Sawtell Cameron. The official {{MoMP|1575|naming citation}} was proposed by the discovering astronomer and published by the Minor Planet Center in December 1952 ({{small|M.P.C. 844}}).<ref name="springer" /><ref name="DoMP-Circular-dates" />
== References == <references>
<ref name="jpldata">{{cite web |type = 2016-10-20 last obs. |title = JPL Small-Body Database Browser: 1575 Winifred (1950 HH) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001575 |publisher = Jet Propulsion Laboratory |access-date = 5 June 2017}}</ref>
<ref name="springer">{{cite book |title = Dictionary of Minor Planet Names – (1575) Winifred |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |page = 125 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1576 |chapter = (1575) Winifred }}</ref>
<ref name="MPC-Winifred">{{cite web |title = 1575 Winifred (1950 HH) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1575 |access-date = 1 February 2016}}</ref>
<ref name="DoMP-Circular-dates">{{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}}</ref>
<ref name="geneva-obs">{{cite web |title = Asteroids and comets rotation curves – (1575) Winifred |last = Behrend |first = Raoul |publisher = Geneva Observatory |url = http://obswww.unige.ch/~behrend/page4cou.html#001575 |access-date = 17 May 2016}}</ref>
<ref name="Ferret">{{cite web |title = Asteroid 1575 Winifred – Nesvorny HCM Asteroid Families V3.0 |work = Small Bodies Data Ferret |url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1575+Winifred#Asteroid%201575%20WinifredEAR-A-VARGBDET-5-NESVORNYFAM-V3.0 |access-date = 26 October 2019}}</ref>
<ref name="lcdb">{{cite LCDB|number = 1575 |access-date = 17 May 2016}}</ref>
<ref name="SIMPS">{{cite journal |first1 = E. F. |last1 = Tedesco |first2 = P. V. |last2 = Noah |first3 = M. |last3 = Noah |first4 = S. D. |last4 = Price |date = October 2004 |title = IRAS Minor Planet Survey V6.0 |url = https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab |journal = NASA Planetary Data System – IRAS-A-FPA-3-RDR-IMPS-V6.0 |bibcode = 2004PDSS...12.....T |access-date = 17 October 2019}}</ref>
<ref name="WISE">{{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 |access-date= 17 May 2016}}</ref>
<ref name="Masiero-2012">{{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 = C. |last6 = Nugent |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 |page = 5 |bibcode = 2012ApJ...759L...8M |doi = 10.1088/2041-8205/759/1/L8 |arxiv = 1209.5794 |access-date= 17 May 2016}}</ref>
<ref name="Warner-2010a">{{Cite journal |author = Warner, Brian D. |date = January 2010 |title = Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2009 June–September |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2010MPBu...37...24W |journal = The Minor Planet Bulletin |volume = 37 |issue = 1 |pages = 24–27 |issn = 1052-8091 |bibcode = 2010MPBu...37...24W |access-date= 17 May 2016}}</ref>
<ref name="Veres-2015">{{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 |access-date= 17 May 2016}}</ref>
<ref name="Masiero-2011">{{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 |access-date= 8 December 2016}}</ref>
</references> <!-- end of reflist -->
== External links == * {{usurped|1=[https://web.archive.org/web/20201107130456/http://www.minorplanetobserver.com/pdolc/A1575_2009.HTM Lightcurve plot of 1575 Winifred]}}, Palmer Divide Observatory, B. D. Warner (2009) * [http://www.minorplanet.info/PHP/lcdbsummaryquery.php Asteroid Lightcurve Database (LCDB)], query form ([http://www.minorplanet.info/lightcurvedatabase.html info] {{Webarchive|url=https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html |date=16 December 2017 }}) * [https://books.google.com/books?id=aeAg1X7afOoC&pg Dictionary of Minor Planet Names], Google books * [http://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève, Raoul Behrend * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1575}} * {{JPL small body}}
{{Minor planets navigator |1574 Meyer |number=1575 |1576 Fabiola}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Winifred}} 001575 001575 Category:Named minor planets 001575 19500420