{{Short description|Stony asteroid from the inner regions of the asteroid belt}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1648 Shajna | background = #D6D6D6 | image = 001648-asteroid shape model (1648) Shajna.png | image_scale = | caption = Shape model of ''Shajna'' from its lightcurve | discovery_ref = <ref name="jpldata" /> | discovered = 5 September 1935 | discoverer = P. Shajn | discovery_site = Simeiz Obs. | mpc_name = (1648) Shajna | alt_names = 1935 RF{{·}}{{mp|1934 CK|1}}<br />1938 MC{{·}}1941 FD<br />1948 LC{{·}}{{mp|1951 EX|2}}<br />1952 SX{{·}}1952 UW<br />1955 QT{{·}}1955 RP<br />A921 GB{{·}}A924 EQ | named_after = Couple of astronomers<br />{{small|(Pelageya and Grigory)}}<ref name="springer" /> | mp_category = main-belt{{·}}{{small|(inner)}}<ref name="lcdb" /> | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 95.99 yr (35,061 days) | aphelion = 2.6971 AU | perihelion = 1.7737 AU | semimajor = 2.2354 AU | eccentricity = 0.2065 | period = 3.34 yr (1,221 days) | mean_anomaly = 250.93° | mean_motion = {{Deg2DMS|0.2949|sup=ms}} / day | inclination = 4.5723° | asc_node = 130.42° | arg_peri = 134.71° | dimensions = {{val|8.26|1.47}} km<ref name="Nugent-2016" /><br />{{val|8.30|0.30}} km<ref name="Masiero-2012" /><br />9.23 km {{small|(calculated)}}<ref name="lcdb" /><br />{{val|9.450|0.141}} km<ref name="WISE" /><ref name="Masiero-2011" /> | rotation = {{val|6.41368|0.00001}} h<ref name="Durech-2016" /><br />{{val|6.41369|0.00005}} h<ref name="Hanus-2016a" /><br />{{val|6.4140|0.0002}} h<ref name="geneva-obs" /><br />{{val|6.4140|0.0164}} h {{small|(R)}}<ref name="Waszczak-2015" /><br />{{val|6.4248|0.0164}} h {{small|(S)}}<ref name="Waszczak-2015" /> | albedo = {{val|0.191|0.016}}<ref name="WISE" /><ref name="Masiero-2011" /><br />0.20 {{small|(assumed)}}<ref name="lcdb" /><br />{{val|0.247|0.049}}<ref name="Masiero-2012" /><br />{{val|0.35|0.13}}<ref name="Nugent-2016" /> | spectral_type = Tholen = S<ref name="jpldata" />{{·}}S<ref name="lcdb" /><br />B–V = 0.792<ref name="jpldata" /><br />U–B = 0.497<ref name="jpldata" /> | abs_magnitude = {{val|11.838|0.003}} {{small|(R)}}<ref name="Waszczak-2015" />{{·}}12.21<ref name="Nugent-2016" />{{·}}12.54<ref name="jpldata" /><ref name="lcdb" /><ref name="Masiero-2012" /><ref name="WISE" /> }}
'''1648 Shajna''', provisional designation {{mp|1935 RF}}, is a stony asteroid from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 5 September 1935, by Russian astronomer Pelageya Shajn at Simeiz Observatory on the Crimean peninsula.<ref name="MPC-Shajna" /> Two weeks later, it was independently discovered by Cyril Jackson at Johannesburg Observatory, South Africa. It was later named after the discoverer and her husband, Russian astronomers Grigory Shajn.<ref name="springer" />
== Orbit and classification ==
''Shajna'' orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,221 days). Its well-determined orbit has an eccentricity of 0.21 and an inclination of 5° with respect to the ecliptic.<ref name="jpldata" /> In 1921, ''Shajna'' was first identified as {{mp|1921 GB}} at Heidelberg Observatory. Its first used observation was taken at Uccle in 1934, when it was identified as {{mp|1934 CK|1}}, extending the body's observation arc by one year prior to its official discovery observation.<ref name="MPC-Shajna" />
== Rotation period ==
In July 2005, a rotational lightcurve of was obtained by French amateur astronomer Laurent Bernasconi. It gave a well-defined rotation period of 6.4140 hours with a brightness variation of 0.65 magnitude ({{small|U=3}}).<ref name="geneva-obs" /> Two modeled lightcurves from various surveys including the Lowell photometric database gave similar periods of 6.41368 and 6.41369 hours ({{small|U=n.a.}}).<ref name="Durech-2016" /><ref name="Hanus-2016a" /> Photometric observations at the Palomar Transient Factory in September 2012, gave nearly identical periods of 6.4140 and 6.4248 hours in the R- and S-band, respectively ({{small|U=2/2}}).<ref name="Waszczak-2015" />
== Diameter and albedo ==
According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, ''Shajna'' measures between 8.26 and 9.45 kilometers in diameter, and its surface has an albedo between 0.191 and 0.35.<ref name="Nugent-2016" /><ref name="Masiero-2012" /><ref name="WISE" /><ref name="Masiero-2011" /> The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 9.23 kilometers with an absolute magnitude of 12.54.<ref name="lcdb" />
== Naming ==
This minor planet was named in honor of the late couple of Russian astronomers Grigory Shajn (1892–1956) and the discoverer herself, Pelageya Shajn (1894–1956), first woman ever to discover a minor planet. The asteroid 1190 Pelagia is also named after her, while her husband is honored by the lunar crater ''Shayn''.<ref name="springer" /> The official {{MoMP|1648|naming citation}} was published by the Minor Planet Center on 20 February 1962 ({{small|M.P.C. 2117}}).<ref name="DoMP-Circular-dates" />
== References == <references>
<ref name="jpldata">{{cite web |type = 2017-03-29 last obs. |title = JPL Small-Body Database Browser: 1648 Shajna (1935 RF) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001648 |publisher = Jet Propulsion Laboratory |access-date = 30 June 2017}}</ref>
<ref name="springer">{{cite book |title = Dictionary of Minor Planet Names – (1648) Shajna |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |page = 131 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1649 |chapter = (1648) Shajna }}</ref>
<ref name="MPC-Shajna">{{cite web |title = 1648 Shajna (1935 RF) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1648 |access-date = 26 December 2016}}</ref>
<ref name="DoMP-Circular-dates">{{cite book |title = Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) |year = 2009 |url = https://archive.org/details/dictionaryminorp2008schm |url-access = limited |chapter = Appendix – Publication Dates of the MPCs |last = Schmadel |first=Lutz D. |publisher = Springer Berlin Heidelberg |page = [https://archive.org/details/dictionaryminorp2008schm/page/n230 221] |isbn = 978-3-642-01964-7 |doi = 10.1007/978-3-642-01965-4|bibcode = 2009dmpn.book.....S }}</ref>
<ref name="geneva-obs">{{cite web |title = Asteroids and comets rotation curves – (1648) Shajna |last = Behrend |first = Raoul |publisher = Geneva Observatory |url = http://obswww.unige.ch/~behrend/page4cou.html#001648 |access-date = 26 December 2016}}</ref>
<ref name="lcdb">{{cite LCDB|number = 1648 |access-date = 26 December 2016}}</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 |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 = 35447010 }}</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 |s2cid = 46350317 |access-date= 26 December 2016}}</ref>
<ref name="Nugent-2016">{{cite journal |display-authors = 6 |first1 = C. R. |last1 = Nugent |first2 = A. |last2 = Mainzer |first3 = J. |last3 = Bauer |first4 = R. M. |last4 = Cutri |first5 = E. A. |last5 = Kramer |first6 = T. |last6 = Grav |first7 = J. |last7 = Masiero |first8 = S. |last8 = Sonnett |first9 = E. L. |last9 = Wright |date = September 2016 |title = NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos |journal = The Astronomical Journal |volume = 152 |issue = 3 |page = 12 |bibcode = 2016AJ....152...63N |doi = 10.3847/0004-6256/152/3/63 |arxiv = 1606.08923 |doi-access = free }}</ref>
<ref name="Hanus-2016a">{{cite journal |display-authors = 6 |first1 = J. |last1 = Hanus |first2 = J. |last2 = Durech |first3 = D. A. |last3 = Oszkiewicz |first4 = R. |last4 = Behrend |first5 = B. |last5 = Carry |first6 = M. |last6 = Delbo |first7 = O. |last7 = Adam |first8 = V. |last8 = Afonina |first9 = R. |last9 = Anquetin |first10 = P. |last10 = Antonini |first11 = L. |last11 = Arnold |first12 = M. |last12 = Audejean |first13 = P. |last13 = Aurard |first14 = M. |last14 = Bachschmidt |first15 = B. |last15 = Baduel |first16 = E. |last16 = Barbotin |first17 = P. |last17 = Barroy |first18 = P. |last18 = Baudouin |first19 = L. |last19 = Berard |first20 = N. |last20 = Berger |first21 = L. |last21 = Bernasconi |first22 = J.-G. |last22 = Bosch |first23 = S. |last23 = Bouley |first24 = I. |last24 = Bozhinova |first25 = J. |last25 = Brinsfield |first26 = L. |last26 = Brunetto |first27 = G. |last27 = Canaud |first28 = J. |last28 = Caron |first29 = F. |last29 = Carrier |first30 = G. |last30 = Casalnuovo |first31 = S. |last31 = Casulli |first32 = M. |last32 = Cerda |first33 = L. |last33 = Chalamet |first34 = S. |last34 = Charbonnel |first35 = B. |last35 = Chinaglia |first36 = A. |last36 = Cikota |first37 = F. |last37 = Colas |first38 = J.-F. |last38 = Coliac |first39 = A. |last39 = Collet |first40 = J. |last40 = Coloma |first41 = M. |last41 = Conjat |first42 = E. |last42 = Conseil |first43 = R. |last43 = Costa |first44 = R. |last44 = Crippa |first45 = M. |last45 = Cristofanelli |first46 = Y. |last46 = Damerdji |last47 = Debackè |first48 = A. |last48 = re |first49 = A. |last49 = Decock |first50 = Q. |last50 = Déhais |first51 = T. |last51 = Déléage |first52 = S. |last52 = Delmelle |first53 = C. |last53 = Demeautis |first54 = M. |last54 = Drózdz |first55 = G. |last55 = Dubos |first56 = T. |last56 = Dulcamara |first57 = M. |last57 = Dumont |first58 = R. |last58 = Durkee |first59 = R. |last59 = Dymock |first60 = A. |last60 = Escalante del Valle |first61 = N. |last61 = Esseiva |first62 = R. |last62 = Esseiva |first63 = M. |last63 = Esteban |first64 = T. |last64 = Fauchez |first65 = M. |last65 = Fauerbach |first66 = M. |last66 = Fauvaud |first67 = S. |last67 = Fauvaud |first68 = E. |last68 = Forné |first69 = C. |last69 = Fournel |first70 = D. |last70 = Fradet |first71 = J. |last71 = Garlitz |first72 = O. |last72 = Gerteis |first73 = C. |last73 = Gillier |first74 = M. |last74 = Gillon |first75 = R. |last75 = Giraud |first76 = J.-P. |last76 = Godard |first77 = R. |last77 = Goncalves |first78 = Hiroko |last78 = Hamanowa |first79 = Hiromi |last79 = Hamanowa |first80 = K. |last80 = Hay |first81 = S. |last81 = Hellmich |first82 = S. |last82 = Heterier |first83 = D. |last83 = Higgins |first84 = R. |last84 = Hirsch |first85 = G. |last85 = Hodosan |first86 = M. |last86 = Hren |first87 = A. |last87 = Hygate |first88 = N. |last88 = Innocent |first89 = H. |last89 = Jacquinot |first90 = S. |last90 = Jawahar |first91 = E. |last91 = Jehin |first92 = L. |last92 = Jerosimic |first93 = A. |last93 = Klotz |first94 = W. |last94 = Koff |first95 = P. |last95 = Korlevic |first96 = E. |last96 = Kosturkiewicz |first97 = P. |last97 = Krafft |first98 = Y. |last98 = Krugly |first99 = F. |last99 = Kugel |first100 = O. |last100 = Labrevoir |first101 = J. |last101 = Lecacheux |first102 = M. |last102 = Lehký |first103 = A. |last103 = Leroy |first104 = B. |last104 = Lesquerbault |first105 = M. J. |last105 = Lopez-Gonzales |first106 = M. |last106 = Lutz |first107 = B. |last107 = Mallecot |first108 = J. |last108 = Manfroid |first109 = F. |last109 = Manzini |first110 = A. |last110 = Marciniak |first111 = A. |last111 = Martin |first112 = B. |last112 = Modave |first113 = R. |last113 = Montaigut |first114 = J. |last114 = Montier |first115 = E. |last115 = Morelle |first116 = B. |last116 = Morton |first117 = S. |last117 = Mottola |first118 = R. |last118 = Naves |first119 = J. |last119 = Nomen |first120 = J. |last120 = Oey |first121 = W. |last121 = Ogloza |first122 = M. |last122 = Paiella |first123 = H. |last123 = Pallares |first124 = A. |last124 = Peyrot |first125 = F. |last125 = Pilcher |first126 = J.-F. |last126 = Pirenne |first127 = P. |last127 = Piron |first128 = M. |last128 = Polinska |first129 = M. |last129 = Polotto |first130 = R. |last130 = Poncy |first131 = J. P. |last131 = Previt |first132 = F. |last132 = Reignier |first133 = D. |last133 = Renauld |first134 = D. |last134 = Ricci |first135 = F. |last135 = Richard |first136 = C. |last136 = Rinner |first137 = V. |last137 = Risoldi |first138 = D. |last138 = Robilliard |first139 = D. |last139 = Romeuf |first140 = G. |last140 = Rousseau |first141 = R. |last141 = Roy |first142 = J. |last142 = Ruthroff |first143 = P. A. |last143 = Salom |first144 = L. |last144 = Salvador |first145 = S. |last145 = Sanchez |first146 = T. |last146 = Santana-Ros |first147 = A. |last147 = Scholz |first148 = G. |last148 = Séné |first149 = B. |last149 = Skiff |first150 = K. |last150 = Sobkowiak |first151 = P. |last151 = Sogorb |first152 = F. |last152 = Soldán |first153 = A. |last153 = Spiridakis |first154 = E. |last154 = Splanska |first155 = S. |last155 = Sposetti |first156 = D. |last156 = Starkey |first157 = R. |last157 = Stephens |first158 = A. |last158 = Stiepen |first159 = R. |last159 = Stoss |first160 = J. |last160 = Strajnic |first161 = J.-P. |last161 = Teng |first162 = G. |last162 = Tumolo |first163 = A. |last163 = Vagnozzi |first164 = B. |last164 = Vanoutryve |first165 = J. M. |last165 = Vugnon |first166 = B. D. |last166 = Warner |first167 = M. |last167 = Waucomont |first168 = O. |last168 = Wertz |first169 = M. |last169 = Winiarski |first170 = M. |last170 = Wolf |date = February 2016 |title = New and updated convex shape models of asteroids based on optical data from a large collaboration network |journal = Astronomy and Astrophysics |volume = 586 |page = 24 |bibcode = 2016A&A...586A.108H |doi = 10.1051/0004-6361/201527441 |arxiv = 1510.07422|s2cid = 119112278 }}</ref>
<ref name="Durech-2016">{{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 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016A&A...587A..48D |journal = Astronomy and Astrophysics |volume = 587 |page = 6 |bibcode = 2016A&A...587A..48D |doi = 10.1051/0004-6361/201527573 |arxiv = 1601.02909 |s2cid = 118427201 |access-date= 26 December 2016}}</ref>
<ref name="Waszczak-2015">{{cite journal |display-authors = 6 |first1 = Adam |last1 = Waszczak |first2 = Chan-Kao |last2 = Chang |first3 = Eran O. |last3 = Ofek |first4 = Russ |last4 = Laher |first5 = Frank |last5 = Masci |first6 = David |last6 = Levitan |first7 = Jason |last7 = Surace |first8 = Yu-Chi |last8 = Cheng |first9 = Wing-Huen |last9 = Ip |first10 = Daisuke |last10 = Kinoshita |first11 = George |last11 = Helou |first12 = Thomas A. |last12 = Prince |first13 = Shrinivas |last13 = Kulkarni |date = September 2015 |title = Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015AJ....150...75W |journal = The Astronomical Journal |volume = 150 |issue = 3 |page = 35 |bibcode = 2015AJ....150...75W |doi = 10.1088/0004-6256/150/3/75 |arxiv = 1504.04041 |s2cid = 8342929 |access-date= 26 December 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 |s2cid = 118745497 |access-date= 26 December 2016}}</ref>
</references> <!-- end of reflist -->
== External links == * [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|1648}} * {{JPL small body}}
{{Minor planets navigator |1647 Menelaus |number=1648 |1649 Fabre}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Shajna}} 001648 Category:Discoveries by Pelageya Shajn Category:Named minor planets 001648 19350905