154 Bertha
{{Short description|Main-belt asteroid}}
{{Use dmy dates|date=September 2018}}
{{Infobox planet
| minorplanet=yes
| background=#D6D6D6
| name=154 Bertha
| image=000154-asteroid shape model (154) Bertha.png
| discoverer=P. M. Henry
| discovered=4 November 1875
| mpc_name=(154) Bertha
| pronounced= {{IPAc-en|'|b|ɜːr|θ|ə}}{{OED|Bertha}}
| alt_names=A875 VD
| mp_category=Main belt
| orbit_ref={{Cite web |url=http://ftp.lowell.edu/pub/elgb/astorb.html |website=astorb |title=The Asteroid Orbital Elements Database |publisher=Lowell Observatory }}
| epoch=31 July 2016 (JD 2457600.5)
| semimajor={{Convert|3.19694|AU|Gm|2|adj=ri2|abbr=on}}
| perihelion={{Convert|2.94994|AU|Gm|2|adj=ri2|abbr=on}}
| aphelion={{Convert|3.44394|AU|Gm|2|adj=ri2|abbr=on|lk=on}}
| eccentricity=0.077261
| period={{convert|2087.9|days|years|2|order=flip}}
| arg_peri=159.722°
| inclination=20.9724°
| asc_node=36.7441°
| mean_anomaly=125.046°
| avg_speed=16.63 km/s
| dimensions={{val|184.93|3.6|ul=km}}
{{val|186.85|1.83|u=km}}
| mass={{val|9.19|5.20|e=18|u=kg}}
| density={{val|2.69|1.52|u=g/cm3}}
| surface_grav=0.0517 m/s²
| escape_velocity=0.0978 km/s
| rotation={{Convert|25.224|h|d|abbr=on|lk=on}}
| axial_tilt=
| pole_ecliptic_lat=
| pole_ecliptic_lon=
| spectral_type=C
| albedo={{val|0.0480|0.002}}
0.0483 ± 0.0107
| single_temperature=~156 K
| mean_motion={{Deg2DMS|0.172426|sup=ms}} / day
| observation_arc=130.75 yr (47758 d)
| uncertainty=0
| moid={{Convert|1.95152|AU|Gm|2|adj=ri2|abbr=on}}
| jupiter_moid={{Convert|1.53096|AU|Gm|2|adj=ri2|abbr=on}}
| tisserand=3.087
}}
154 Bertha is a main-belt asteroid. It was discovered by the French brothers Paul Henry and Prosper Henry on 4 November 1875, but the credit for the discovery was given to Prosper. It is probably named after Berthe Martin-Flammarion, sister of the astronomer Camille Flammarion.
Observations performed at the Palmer Divide Observatory in Colorado Springs, Colorado in during 2007 produced a light curve with a period of 22.30 ± 0.03 hours and a brightness range of 0.10 ± 0.02 in magnitude. A 1998 measurement gave a value of 27.6 hours, which doesn't fit the PDO data. In 2011, observations from the Organ Mesa Observatory in Las Cruces, New Mexico were used to determine a rotation period of 25.224 ± 0.002 hours with a brightness variability of 0.10 ± 0.01 magnitude, ruling out previous studies.
This is classified as a C-type asteroid and it has an estimated diameter of about 187 km.
References
{{Reflist|refs=
| first1 = Donald K.
| last1 = Yeomans
| title = 154 Bertha
| work = JPL Small-Body Database Browser
| publisher = NASA Jet Propulsion Laboratory
| url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=154
| accessdate= 12 May 2016
| postscript= .}}
| first1 = Lutz D.
| last1 = Schmadel
| title = Dictionary of Minor Planet Names
| publisher = Springer
| page = 27
| edition = 6th
| year = 2012
| isbn = 3642297188
| url = https://books.google.com/books?id=aeAg1X7afOoC&pg=PA27
| postscript= .}}
| first1 = B.
| last1 = Carry
| title = Density of asteroids
| work = Planetary and Space Science
| volume = 73
| pages = 98–118
|date=December 2012
| doi = 10.1016/j.pss.2012.03.009
| bibcode = 2012P&SS...73...98C
| postscript= .
|arxiv = 1203.4336 }} See Table 1.
| first1 = Brian D.
| last1 = Warner
| title = Asteroid Lightcurve Analysis at the Palmer Divide Observatory
| work = The Minor Planet Bulletin
|date=September 2007
| bibcode = 2007MPBu...34...72W
| postscript= .}}
| last1 = Pravec
| first1 = P.
| last2 = Harris
| first2 = A. W.
| last3 = Kusnirak
| first3 = P.
| last4 = Galad
| first4 = A.
| last5 = Hornoch
| first5 = K.
| display-authors = 1
| title = Absolute Magnitudes of Asteroids and a Revision of Asteroid Albedo Estimates from WISE Thermal Observations
| work = Asteroids, Comets, Meteors 2012, Proceedings of the conference held May 16–20, 2012 in Niigata, Japan
| issue = 1667
|date=May 2012
| bibcode = 2012LPICo1667.6089P
| postscript= .}} See Table 4.
| last1 = Pilcher
| first1 = Frederick
| title = Rotation Period Determinations for 31 Euphrosyne, 65 Cybele, 154 Bertha 177 Irma, 200 Dynamene, 724 Hapag, 880 Herba, and 1470 Carla
| work = The Minor Planet Bulletin
| volume = 39
| issue = 2
| pages = 57–60
|date=April 2012
| bibcode = 2012MPBu...39...57P
| postscript= .}}
}}
External links
- [http://www.minorplanetobserver.com/pdolc/A154_2007.HTM Lightcurve plot of 154 Bertha], Palmer Divide Observatory, B. D. Warner (2007)
- [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://minorplanetcenter.net//iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
- {{AstDys|154}}
- {{JPL small body}}
{{Minor planets navigator |153 Hilda |number=154 |155 Scylla}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Bertha}}
Category:Discoveries by Paul Henry and Prosper Henry
{{C-beltasteroid-stub}}