135 Hertha

Main-belt asteroid September 2018 yes 135 Hertha #D6D6D6 135 Hertha.png Lightcurve-based 3D model of Hertha on the top with an image of the asteroid on the bottom C. H. F. Peters Litchfield Obs. 18 February 1874 (135) Hertha A874 DAThe MPC notates Hertha's retroactive new-style designation as 1874 DA. ' h ɜr θ ə Nerthus(Norse mythology) main-belt(inner)Nysa–Polana complex (Hertha) 23 March 2018 (JD 2458200.5) 0 133.34 yr (48,701 d) 2.9320 AU 1.9239 AU 2.4279 AU 0.2076 3.78 yr (1,382 d) 233.89° 0.2605 ms / day 2.3052° 343.65° 340.16° 76.12 ± 3.29 km79.24 2.0 km (1.21 ± 0.16) × 1018 kg 5.23 ± 0.96 g/cm3 8.40061 h Shapes and rotational properties of thirty asteroids from photometric data Torppa J. August 2003 Icarus 164 2 346–383 10.1016/S0019-1035(03)00146-5 2003Icar..164..346T etal 0.1436 M or X M-type Asteroids: Rotational properties of 16 Objects Dotto E. October 1992 Astronomy and Astrophysics Supplement Series 95 2 195–211 1992A&AS...95..195D etal 8.23 135 Hertha is an asteroid from the inner region of the asteroid belt, approximately 77 km mi off us in diameter. Discovered on 18 February 1874 by German–American astronomer Christian Peters at the Litchfield Observatory near Clinton, New York, it was named after the Teutonic and Scandinavian goddess of fertility, Hertha, also known as Nerthus. It orbits among the Nysa–Polana complex, but its classification as a metallic M-type asteroid does not match the more common carbonaceous and silicaceous compositions seen in this family. Asteroid 'clans': Super-families or multiple events? Cellino A. Vincenzo, Z. October 1993 Celestial Mechanics and Dynamical Astronomy 57 1–2 34–37 1993CeMDA..57...37C 10.1007/BF00692459 Spectroscopic analysis indicates the possible presence of hydrated silicates indicating that Hertha should possibly be reclassified from its present M-type to the proposed W-type. The Puzzling Case of the Nysa–Polana Family Cellino A. August 2001 Icarus 152 2 225–237 10.1006/icar.2001.6634 2001Icar..152..225C etal Lightcurve data from Hertha indicates a flattened body, and radar observations indicate that Hertha is non-metallic. More Results from a Long-Term Radar Survey of M-Class Asteroids Shepard M.K. September 2006 Bulletin of the American Astronomical Society 38 626 2006DPS....38.7101S etal Five occultations of stars by the asteroid have been observed between 2000 and 2015. Discovery Hertha was discovered by C. H. F. Peters on 18 February 1874, in Clinton, New York. Further observations were carried out in 1883 by W. T. Sampson and communicated to Astronomische Nachrichten on his behalf by Rear Admiral R. W. Shufeldt https://web.archive.org/web/20110629095756/http://www.arlingtoncemetery.net/rwshufeldt-usn.htm 29 June 2011 . Observations of (135) Hertha made at the Naval Observatory Washington with 9.6 inch equatorial Sampson W.T. Shufeldt, R. W. 1884 Astronomische Nachrichten 107 20 323 1883AN....107..323S 10.1002/asna.18841072006 https://zenodo.org/record/1424719 Physical properties After its discovery in 1874, subsequent observations in 1884 established Hertha's orbit. Astronomers then began investigation of its physical properties. As early as 1904, G. W. Hill reported observations of Hertha's brightness indicating a variation of half a magnitude and a short period. Variability of (135) Hertha Hill G.W. March 1904 Astronomical Journal 24 557 42 1904AJ.....24...42H 10.1086/103543 In October 1992 Dotto et al. performed 20 hours of observations spread over 6 nights to investigate Hertha rotational period, approximate shape, and the coordinates of its rotational axis. They were able to confirm a rotational period of 8.398 ± .001 hours as previously measured by Harris et al. published earlier in 1992. Asteroid lightcurve observations from 1981 Harris A.W. January 1992 Icarus 95 1 115–147 10.1016/0019-1035(92)90195-D 1992Icar...95..115H etal In the same study, Dotto et al. measured the asteroid's shape and rotational axis. The axes' ratios were found to be: a/b = 1.34 ± .03 and b/c = 1.22 ± .05. Two possible values were determined for the rotational axis, however further measurements at different ecliptic longitudes are required to determine which is correct. In August 2003 Torppa et al. published their results on the shape and rotational properties of a number of asteroids, including Hertha. Utilizing data from 42 lightcurves of Hertha spanning from 1978 to 2002, a more refined set of axes' ratios was obtained and a detailed shape model was obtained through inversion. New values for the axes' ratios are: a/b = 1.1 and b/c = 1.5. Measurements of the pole direction were also obtained, however like Dotto et al. they were unable to differentiate between their two possible solutions of (β=+58°, λ=96°) and (β=+53°, λ=274°). In 2017, Hanuš et al. confirmed that the correct solution is β=53 3°, λ=277 3°. They also calculated the first non-convex shape model, based on lightcurve and stellar occultation data. Spectral classification Although Hertha has long been classified as an M-type asteroid based on its spectral properties, observations carried out by Rivkin et al. in 1996 using the IRTF at Mauna Kea Observatory have raised the possibility of reclassification. The presence of a dip in the observed spectrum at 3 μm indicates that the surface is hydrated, suggesting that Hertha should be reclassified as a W-type (a "wet M-type") asteroid. The Nature of M-Class Asteroids from 3-μm Observations Rivkin A.S. June 2000 Icarus 145 2 351–368 10.1006/icar.2000.6354 2000Icar..145..351R etal Based on work carried out by Salisbury and Walter, the Rivkin study estimated the water content of the asteroid to be between 0.14 and 0.27 percent by mass. This estimate is based on laboratory measurements and may not be applicable to asteroids in space. A more recent study by Rivkin et al. published in 2002 examined the dependence of spectral absorption on the asteroid's rotational phase. The study looked at the 0.7 μm band, which is also associated with hydrated silicates, and found that the reflectance changes as the asteroid rotates, suggesting that the surface is heterogeneous with some hydrated areas intermixed with dry areas. Hydrated Minerals on Asteroids: The Astronomical Record Rivkin A.S. March 2002 Technical Report, Massachusetts Institute of Technology http://www.lpi.usra.edu/books/AsteroidsIII/pdf/3031.pdf etal Asteroid family Nysa–Polana complex Hertha believed to be the largest member of two overlapping asteroid families in the inner main belt, known as the Hertha families (also historically known as the "Nysa family"). These two families also overlap with several other unrelated asteroid families, together forming the Nysa–Polana complex. The Hertha families are divided by color and spectral type: S-type asteroids belong to the "Hertha1" family while X-type asteroids belong to the "Hertha2" family. Of these, the Hertha1 family is larger in population. The asteroids of both Hertha families are believed to be collisional fragments from Hertha, although it is unclear whether both families formed together from one collision event or formed separately in different collision events. In either case, the different compositions of the Hertha families suggest that the parent body must have compositionally different layers. Notes References 2018-05-22 last obs. JPL Small-Body Database Browser: 135 Hertha https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000135 Jet Propulsion Laboratory 18 September 2018 27 Schmadel Lutz D. Dictionary of Minor Planet Names Springer Berlin Heidelberg 2007 978-3-540-00238-3 10.1007/978-3-540-29925-7_136 (135) Hertha 135 Hertha Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=135 18 September 2018 Observations of the Planet Hertha (135), made at the Litchfield Observatory of Hamilton College Peters C.A.F. 1874 Astronomische Nachrichten 84 2001 129 1874AN.....84..129P 10.1002/asna.18740840902 https://zenodo.org/record/1424687 Asteroid (135) Hertha AstDyS-2, Asteroids – Dynamic Site https://newton.spacedys.com/astdys/index.php?n=135&pc=1.1.6 18 September 2018 Asteroid 135 Hertha Small Bodies Data Ferret https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=135+Hertha 18 September 2018 18 September 2018 https://web.archive.org/web/20180918054625/https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=135+Hertha dead Carry B. Density of asteroids Planetary and Space Science 73 1 2012 0032-0633 10.1016/j.pss.2012.03.009 98–118 2012P&SS...73...98C 1203.4336 See Table 1. Dykhuis Melissa J. Greenberg Richard Collisional family structure within the Nysa–Polana complex Icarus May 2015 252 199–211 10.1016/j.icarus.2015.01.012 1501.04649 2015Icar..252..199D Hanuš J. Viikinkoski M. Marchis F. Ďurech J. Kaasalainen M. Delbo' M. Herald D. Frappa E. Hayamizu T. Kerr S. Preston S. Timerson B. Dunham D. Talbot J. Volumes and bulk densities of forty asteroids from ADAM shape modeling Astronomy & Astrophysics 601 2017 0004-6361 10.1051/0004-6361/201629956 A114 1702.01996 1 2017A&A...601A.114H etal Marsset M. Vernazza P. Brož M. Avdellidou C. Thomas C. A. McGraw L. The Nysa family as the main source of unequilibrated LL ordinary chondrites June 2026 Astronomy & Astrophysics 710 A389 free 10.1051/0004-6361/202659352 2602.08732 2026A&A...710A.389M Bottke William F. Vokrouhlický David Dykhuis Melissa Zellner Nicolle An 800 Myr-old Impact Shower on the Terrestrial Planets from the Breakup of the Eulalia Parent Body July 2026 The Planetary Science Journal 7 7 171 free 10.3847/PSJ/ae74cc 2606.05036 2026PSJ.....7..171B Further reading Near-IR spectral evidence for the presence of iron-poor orthopyroxenes on the surfaces of six M-type asteroids Hardersen Paul S. Gaffey Michael J. Abell Paul A. May 2005 Icarus 175 1 141–158 10.1016/j.icarus.2004.10.017 2005Icar..175..141H Near-infrared Reflectance Spectra Of 135 Hertha, 224 Oceana, 516 Amherstia, And 872 Holda Hardersen Paul S. Gaffey Michael J. Abell Paul A. September 2006 Bulletin of the American Astronomical Society 38 626 2006DPS....38.7103H External links Lightcurve plot of 135 Hertha, Palmer Divide Observatory, B. D. Warner (2008) 2008-Dec-11 Occultation / (2008 Asteroidal Occultation Results for North America) Asteroid Lightcurve Database (LCDB), query form (info https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html 16 December 2017 ) Dictionary of Minor Planet Names, Google books Asteroids and comets rotation curves, CdR https://web.archive.org/web/20160729213840/http://obswww.unige.ch/~behrend/page_cou.html 29 July 2016 – Observatoire de Genève, Raoul Behrend Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center 135 134 Sophrosyne 135 136 Austria 000135 Category:Discoveries by Christian Peters Category:Named minor planets 000135 000135 000135 18740218