2709 Sagan
{{Short description|Asteroid named in honor of Carl Sagan}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
| minorplanet = yes
| name = 2709 Sagan
| background = #D6D6D6
| image = 2709Sagan (Lightcurve Inversion).png
| image_scale =
| caption = {{longitem|Lightcurve-based 3D-model of Sagan|style=padding: 5px 0; line-height: 1.3em;}}
| discovered = 21 March 1982
| discoverer = E. Bowell
| discovery_site = Anderson Mesa Stn.
| mpc_name = (2709) Sagan
| alt_names = 1982 FH{{·}}{{mp|1951 WF|1}}
1959 CC{{·}}{{mp|1959 EA|1}}
1964 WT{{·}}{{mp|1982 FE|2}}
| named_after = Carl Sagan {{small|(astronomer and science communicator)}}
| mp_category = main-belt{{·}}Flora
| epoch = 4 September 2017 (JD 2458000.5)
| uncertainty = 0
| observation_arc = 58.15 yr (21,239 days)
| aphelion = 2.3475 AU
| perihelion = 2.0428 AU
| semimajor = 2.1952 AU
| eccentricity = 0.0694
| period = 3.25 yr (1,188 days)
| mean_anomaly = 319.11°
| mean_motion = {{Deg2DMS|0.3030|sup=ms}} / day
| inclination = 2.7318°
| asc_node = 241.13°
| arg_peri = 308.48°
| dimensions = {{val|6.559|0.196}} km
6.81 km {{small|(calculated)}}
| rotation = {{val|5.254|0.001}} h
{{val|5.2557|0.0002}} h{{efn|name=Pravec-2016}}
{{val|5.2564|0.0007}} h{{efn|name=Pravec-2011}}
{{val|5.258|0.002}} h
| albedo = 0.24 {{small|(assumed)}}
{{val|0.259|0.043}}
| spectral_type = SMASS = S{{·}}S
| abs_magnitude = {{val|12.13|1.03}}{{·}}13.0
}}
2709 Sagan, provisional designation {{mp|1982 FH}}, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 6.7 kilometers in diameter. It was discovered on 21 March 1982, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station near Flagstaff, Arizona, and named after astronomer and science popularizer Carl Sagan.
Orbit and classification
Sagan is a member of the Flora family, one of the largest families of stony asteroids. It orbits the Sun in the inner main-belt at a distance of 2.0–2.3 AU once every 3 years and 3 months (1,188 days). Its orbit has an eccentricity of 0.07 and an inclination of 3° with respect to the ecliptic.
Physical characteristics
In the SMASS classification, Sagan is classified as a S-type asteroid. It has an albedo of 0.26, according to observations made by the Wide-field Infrared Survey Explorer and subsequent NEOWISE mission. The body has a rotation period between 5.254 and 5.258 hours and a brightness variation between 0.09 and 0.63 magnitude ({{small|U=3/3/3/3}}).{{efn|name=Pravec-2016}}{{efn|name=Pravec-2011}}
Naming
This minor planet was named in honor of Carl Sagan (1934–1996), planetary scientist at Cornell University, science popularizer, editor of the journal Icarus, and founder of The Planetary Society. Sagan participated on a number of planetary space missions, including the Voyager mission to the outer planets and the Mariner 9 and Viking program to Mars.
Sagan's research encompassed studies of the greenhouse effect on Venus, the atmosphere and surface of Titan, windblown dust on Mars, and the possibility of extraterrestrial intelligent life. Sagan won the Pulitzer Prize for literature in 1978. The official naming citation was published by the Minor Planet Center on 4 August 1982 ({{small|M.P.C. 7158}}).
An asteroid discovered in 1998, 4970 Druyan, is named after Sagan's wife Ann Druyan and is said to be in a "wedding ring orbit" with respect to 2709 Sagan.{{cite web |last1=Palmer |first1=Rob |title=Exploring 'Possible Worlds' With Ann Druyan |url=https://skepticalinquirer.org/2020/06/exploring-possible-worlds-with-ann-druyan/ |website=Skepticalinquirer.org |volume=44 |number=4 |publisher=Center for Inquiry |accessdate=17 April 2020 |archiveurl=https://web.archive.org/web/20200401031822/https://skepticalinquirer.org/exclusive/exploring-possible-worlds-with-ann-druyan/ |archivedate=1 April 2020 |date=June 2020 |url-status=live |quote=[...] asteroids named after each of us that are in perpetual wedding ring orbit around the Sun. Imagine one orbit. And then imagine that the orbit of the other asteroid goes in and out of the other's orbit. So, if you had two wedding rings that were linked together, that's a wedding ring orbit. }}
Notes
{{notelist|refs=
{{efn|name=Pravec-2011|1=Pravec, Petr (2011): [http://www.asu.cas.cz/~asteroid/02709_b1.png lightcurve plot of (2709) Sagan] rotation period of {{val|5.2564|0.0007}} hours with a brightness amplitude of {{val|0.09}} mag (U{{=}}3). Summary figures at [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=2709%7CSagan Collaborative Asteroid Lightcurve Link (CALL)]}}
{{efn|name=Pravec-2016|1=Pravec, Petr (2016): [http://www.asu.cas.cz/~asteroid/02709_b6.png lightcurve plot of (2709) Sagan] with a rotation period of {{val|5.2557|0.0002}} hours with a brightness amplitude of {{val|0.63}} mag (U{{=}}3). Summary figures for (2709) Sagan at [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=2709%7CSagan Collaborative Asteroid Lightcurve Link (CALL)]}}
}}
References
{{reflist|refs=
|type = 2017-03-29 last obs.
|title = JPL Small-Body Database Browser: 2709 Sagan (1982 FH)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2002709
|archive-url = https://web.archive.org/web/20200804094432/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2002709
|url-status = dead
|archive-date = 4 August 2020
|publisher = Jet Propulsion Laboratory
|accessdate = 14 June 2017}}
|title = Dictionary of Minor Planet Names – (2709) Sagan
|last = Schmadel | first = Lutz D. |authorlink=Lutz D. Schmadel
|publisher = Springer Berlin Heidelberg
|pages = 221–222
|date = 2007
|isbn = 978-3-540-00238-3
|doi = 10.1007/978-3-540-29925-7_2710 |chapter = (2709) Sagan }}
|title = 2709 Sagan (1982 FH)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=2709
|accessdate = 6 December 2016}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|accessdate = 6 December 2016}}
|title = LCDB Data for (2709) Sagan
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=2709%7CSagan
|accessdate = 6 December 2016}}
|first1 = Joseph R. |last1 = Masiero |authorlink1=Joseph Masiero
|first2 = Amy K. |last2 = Mainzer |authorlink2=Amy Mainzer
|first3 = Tommy |last3 = Grav |authorlink3=Tommy Grav
|first4 = James M. |last4 = Bauer |authorlink4=James Bauer (astronomer)
|first5 = Roc M. |last5 = Cutri
|first6 = Carrie |last6 = Nugent |authorlink6=Carrie Nugent
|first7 = Mario 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= 6 December 2016}}
|first1 = David J. |last1 = Higgins |authorlink1=David Higgins (astronomer)
|first2 = Petr |last2 = Pravec |authorlink2=Petr Pravec
|first3 = Peter |last3 = Kušnirák |authorlink3=Peter Kušnirák
|first4 = Kamil |last4 = Hornoch |authorlink4=Kamil Hornoch
|first5 = James W. |last5 = Brinsfield
|first6 = Bill |last6 = Allen
|first7 = Brian D. |last7 = Warner |authorlink7=Brian D. Warner
|date = September 2008
|title = Asteroid Lightcurve Analysis at Hunters Hill Observatory and Collaborating Stations: November 2007 – March 2008
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2008MPBu...35..123H
|journal = The Minor Planet Bulletin
|volume = 35
|issue = 3
|pages = 123–126
|issn = 1052-8091
|bibcode = 2008MPBu...35..123H
|access-date= 6 December 2016}}
|display-authors = 6
|first1 = Julian |last1 = Oey |authorlink1=Julian Oey
|first2 = Raguli Ya. |last2 = Inasaridze
|first3 = Otar I. |last3 = Kvaratskhelia
|first4 = Vova |last4 = Ayvazian
|first5 = Vasilij G. |last5 = Chirony
|first6 = Yurij N. |last6 = Krugly
|first7 = Igor E. |last7 = Molotov
|first8 = Brian D. |last8 = Warner
|first9 = Petr |last9 = Pravec
|first10 = Peter |last10 = Kušnirák
|first11 = David J. |last11 = Higgins
|first12 = Joseph |last12 = Pollock
|first13 = Joshua |last13 = Haislip
|first14 = Kevin |last14 = Ivarsen
|first15 = Daniel |last15 = Reichart
|first16 = Aaron |last16 = Lacluyze
|first17 = Adrian |last17 = Galád
|date = July 2013
|title = Lightcurve Analysis is Search of Binary Asteroids
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2013MPBu...40..169O
|journal = The Minor Planet Bulletin
|volume = 40
|issue = 3
|pages = 169–172
|issn = 1052-8091
|bibcode = 2013MPBu...40..169O
|access-date= 6 December 2016}}
|display-authors = 6
|first1 = Peter |last1 = Vereš |authorlink1=Peter Vereš
|first2 = Robert |last2 = Jedicke
|first3 = Alan |last3 = Fitzsimmons |authorlink3=Alan 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= 6 December 2016}}
}}
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 }})
- Schmadel, Lutz D.; [https://books.google.com/books?id=aeAg1X7afOoC&pg Dictionary of Minor Planet Names], Google books
- Behrend, Raoul; [http://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève
- [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
- {{AstDys|2709}}
- {{JPL small body}}
{{Minor planets navigator |2708 Burns |number=2709 |2710 Veverka}}
{{Small Solar System bodies}}
{{Carl Sagan}}
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