2608 Seneca
{{Short description|Stony asteroid and sub-kilometer near-Earth object}}
{{Use dmy dates|date=October 2019}}
{{Infobox planet
| minorplanet = yes
| name = 2608 Seneca
| background = #FFC2E0
| image =
| image_size =
| caption =
| discovered = 17 February 1978
| discoverer = H.-E. Schuster
| discovery_site = La Silla Obs.
| mpc_name = (2608) Seneca
| alt_names = 1978 DA
| pronounced = {{IPAc-en|ˈ|s|ɛ|n|ᵻ|k|ə}} {{respell|SEN|ik|ə}}{{OED|Seneca}}
| named_after = Seneca the Younger
{{small|(Roman philosopher)}}
| epoch = 4 September 2017 (JD 2458000.5)
| uncertainty = 1
| observation_arc = 38.92 yr (14,217 days)
| aphelion = 3.9532 AU
| perihelion = 1.0777 AU
| semimajor = 2.5154 AU
| eccentricity = 0.5716
| period = 3.99 yr (1,457 days)
| mean_anomaly = 353.12°
| mean_motion = {{Deg2DMS|0.2471|sup=ms}} / day
| inclination = 14.682°
| asc_node = 167.37°
| arg_peri = 37.350°
| moid = 0.1321 AU{{·}}51.5 LD
| dimensions = 0.9 km
{{val|1.0|0.3}}
| rotation = {{val|8}} h
| albedo = {{val|0.15|0.03}}
0.20 {{small|(derived)}}
0.21
| spectral_type = Tholen = S{{·}}S
B–V = 0.826
U–B = 0.454
| abs_magnitude = 17.52{{·}}17.59{{·}}17.73
}}
2608 Seneca, provisional designation {{mp|1978 DA}}, is a stony asteroid and sub-kilometer near-Earth object of the Amor group, approximately 0.9 kilometers in diameter. It was discovered on 17 February 1978, by German astronomer Hans-Emil Schuster at ESO's La Silla Observatory in northern Chile, and named after Roman philosopher Seneca.
Orbit
Seneca orbits the Sun at a distance of 1.1–4.0 AU once every 3 years and 12 months (1,457 days). Its orbit has an eccentricity of 0.57 and an inclination of 15° with respect to the ecliptic.
The body's observation arc begins with its official discovery observation in 1978, as no precoveries were taken, and no prior identifications were made.
= Close approaches =
Seneca has an Earth minimum orbital intersection distance of {{convert |0.1321 |AU |km |abbr=on |lk=off |sigfig=3}}, which corresponds to 51.5 lunar distances. On 22 March 2062, it will pass {{convert |0.254 |AU |km |abbr=on |lk=off |sigfig=3}} from the Earth.
Physical characteristics
In the Tholen taxonomy, Seneca is a stony S-type asteroid.
= Photometry =
In March 1978, a photometric observations taken by Degewij and Lebofsky at the Lunar and Planetary Laboratory, Arizona, using a 154-cm reflector, gave a rotational lightcurve with a rotation period of 8 hours and a brightness amplitude of 0.4 (0.5) magnitude ({{small|U=2}}).
= Radiometry =
In addition, radiometric observations by L. and M. Lebofsky with the 71-cm reflector gave a mean-diameter of {{val|1.0|0.3}} kilometers and albedo of {{val|0.15|0.03}}.
= Diameter and albedo =
The Minor Planet Center classifies Seneca as an object larger than 1 kilometer ("1+ KM Near-Earth Object"), while Collaborative Asteroid Lightcurve Link derives an albedo of 0.20 and a diameter of 0.9 kilometers based on an absolute magnitude of 17.59. In 1994, astronomer Tom Gehrels published a diameter of 0.9 kilometers with an albedo of 0.21 in his Hazards Due to Comets and Asteroids.
Naming
This minor planet was named after Roman philosopher and statesman Lucius Annaeus Seneca (c. 4 BC – AD 65), also known as "Seneca the Younger" or simply "Seneca". The approved naming citation was published by the Minor Planet Center on 8 April 1982 ({{small|M.P.C. 6835}}). The lunar crater Seneca was also named in his honor.
References
{{reflist|30em|refs=
|type = 2017-01-20 last obs.
|title = JPL Small-Body Database Browser: 2608 Seneca (1978 DA)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2002608
|publisher = Jet Propulsion Laboratory
|accessdate = 3 July 2017}}
|title = Dictionary of Minor Planet Names – (2608) Seneca
|last = Schmadel | first = Lutz D.
|publisher = Springer Berlin Heidelberg
|page = 213
|date = 2007
|isbn = 978-3-540-00238-3
|doi = 10.1007/978-3-540-29925-7_2609 |chapter = (2608) Seneca }}
|title = 2608 Seneca (1978 DA)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=2608
|accessdate = 26 March 2017}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|accessdate = 26 March 2017}}
|type = 2010-08-19 last obs
|title = JPL Close-Approach Data: 2608 Seneca (1978 DA)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Seneca;cad=1#cad
|accessdate = 15 April 2016}}
|title = LCDB Data for (2608) Seneca
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=2608%7CSeneca
|accessdate = 26 March 2017}}
|first1 = J. |last1 = Degewij
|first2 = L. |last2 = Lebofsky
|first3 = M. |last3 = Lebofsky
|date = March 1978
|title = 1978 CA and 1978 DA
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1978IAUC.3193....1D
|journal = IAU Circ.
|volume = 3193
|issue = 3193
|pages = 1
|bibcode = 1978IAUC.3193....1D
|access-date= 26 March 2017}}
|first1 = H. E. |last1 = Schuster
|first2 = A. |last2 = Surdej
|first3 = J. |last3 = Surdej
|date = September 1979
|title = Photoelectric observations of two unusual asteroids - 1978 CA and 1978 DA
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1979A&AS...37..483S
|journal = Astronomy and Astrophysics Supplement Series
|volume = 37
|pages = 483–486
|bibcode = 1979A&AS...37..483S
|access-date= 26 March 2017}}
}}
External links
- [http://www.uapress.arizona.edu/Books/bid155.htm Hazards Due to Comets and Asteroids], Tom Gehrels (1994/5)
- [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
- {{NeoDys|2608}}
- {{ESA-SSA|2608|Seneca}}
- {{JPL small body}}
{{Minor planets navigator |2607 Yakutia |number=2608 |2609 Kiril-Metodi}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Seneca}}