1777 Gehrels

Asteroid October 2019 yes 1777 Gehrels #D6D6D6 24 September 1960 C. J. van HoutenI. van Houten-G.T. Gehrels Palomar Obs. (1777) Gehrels 4007 P-L1937 GN1941 BU1951 QB1958 DAA905 UEA923 AA Tom Gehrels (astronomer) main-belt(middle) 4 September 2017 (JD 2458000.5) 0 111.43 yr (40,699 days) 2.6705 AU 2.5810 AU 2.6258 AU 0.0171 4.25 yr (1,554 days) 37.596° 0.2316 ms / day 3.1476° 334.69° 131.12° 11.860 0.18412.486 0.228 km12.667 km12.67 km (taken)13.14 1.25 km 2.83 0.05 h2.83552 0.00001 h2.8356 0.0002 hlcdb-Praveclightcurve-plot-Pravec2.8356 0.0001 hlcdb-Pravec2.8358 0.0001 h2.836 0.001 h2.837 0.002 h2.840 0.004 hlightcurve-plot-Wisniewski 0.21510.2212 0.01700.244 0.0130.277 0.274 SMASS = SqS 11.4211.611.77 0.03lcdb-Pravec11.773 0.0311.7811.78 0.05 1777 Gehrels, also designated 4007 P-L, is a stony asteroid from the middle region of the asteroid belt, approximately 13 kilometers in diameter. It was discovered during the Palomar–Leiden survey in 1960, and named for astronomer Tom Gehrels, one of the survey's principal investigators and credited discoverer. Discovery Gehrels was discovered during the Palomar–Leiden survey by the Dutch astronomer couple Ingrid and Cornelis van Houten, in collaboration with Dutch–American astronomer Tom Gehrels at Palomar Observatory, California, on 24 September 1960. The survey designation "P-L" stands for Palomar–Leiden, named after Palomar and Leiden Observatory, which collaborated on the fruitful Palomar–Leiden survey in the 1960s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory, where astrometry was carried out. The trio are credited with the discovery of several thousand minor planets. Orbit and classification It orbits the Sun in the central main-belt at a distance of 2.6–2.7 AU once every 4 years and 3 months (1,554 days). Its orbit has an eccentricity of 0.02 and an inclination of 3° with respect to the ecliptic. First observed as A905 UE at Heidelberg Observatory in 1905, Gehrels first used observation was made at Goethe Link Observatory in 1958, extending the body's observation arc by 2 years prior to its official discovery at Palomar. Physical characteristics This S-type asteroid is characterized as a transitional Sq-type in the SMASS classification. Diameter and albedo According to the survey carried out by NASA's Wide-field Infrared Survey Explorer (WISE) with its subsequent NEOWISE mission, Gehrels measures between 11.860 and 13.14 kilometers in diameter and its surface has an albedo between 0.2212 and 0.277. The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-data and takes an albedo of 0.2151 with a diameter of 12.67 kilometers based on an absolute magnitude of 11.773. Lightcurves Several rotational lightcurve of Gehrels were obtained from photometric observations by astronomers Wiesław Wiśniewski, Petr Pravec, Pierre Antonini, Raoul Behrend, Donn Starkey, Laurent Bernasconi, Jacques Montier, Serge Heterier, Daniel Klinglesmith and Robert Stephens. Lightcurve analysis gave a rotation period between 2.83 and 2.840 hours with a brightness variation of 0.21 and 0.27 magnitude (U=2/3/3/2+/2/3).lcdb-Praveclightcurve-plot-Praveclightcurve-plot-Wisniewski Naming This minor planet was named in honor of Dutch-born American astronomer Tom Gehrels (1925–2011), professor at the University of Arizona, staff member of the LPL research center at Tucson, a principal investigator in the Pioneer program, receiver of the Masursky Award, initiator of the Spacewatch project, and co-discoverer of thousands of minor planets in the Palomar–Leiden survey (see above). He was a pioneer in the field of photometric and polarimetric observations of Solar System bodies in the 1950s. The official 1777 naming citation was published by the Minor Planet Center on 25 September 1971 (M.P.C. 3185). Notes 30em lcdb-Pravec Pravec (2005) web: rotation period 2.8356 0.0002 hours with a brightness amplitude of 0.23 mag. Pravec (1990) web:rotation period 2.8356 0.0001 hours with a brightness amplitude of 0.21 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (1777) Gehrels lightcurve-plot-Pravec Lightcurve plot A and lightcurve plot B by Petr Pravec (2005) from Ondrejov data obtained by the NEO Photometric Program and collaborating projects lightcurve-plot-Wisniewski Lightcurve plot by Petr Pravec from re-analysis of the Wisniewski et al. (1997) data References 30em 2017-03-29 last obs. JPL Small-Body Database Browser: 1777 Gehrels (4007 P-L) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001777 https://web.archive.org/web/20200820203015/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001777 dead 20 August 2020 Jet Propulsion Laboratory 8 June 2017 Dictionary of Minor Planet Names – (1777) Gehrels Schmadel Lutz D. Springer Berlin Heidelberg 142 2007 978-3-540-00238-3 10.1007/978-3-540-29925-7_1778 (1777) Gehrels 1777 Gehrels (4007 P-L) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=1777 15 May 2016 Minor Planet Discoverers Minor Planet Center https://www.minorplanetcenter.net/iau/lists/MPDiscsNum.html 24 April 2016 15 May 2016 Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) Appendix – Publication Dates of the MPCs Schmadel Lutz D. Springer Berlin Heidelberg 221 978-3-642-01964-7 10.1007/978-3-642-01965-4 Asteroids and comets rotation curves – (1777) Gehrels Behrend Raoul Geneva Observatory http://obswww.unige.ch/~behrend/page4cou.html#001777 15 May 2016 1 April 2019 https://web.archive.org/web/20190401181659/http://obswww.unige.ch/~behrend/page4cou.html#001777 dead 1777 15 May 2016 6 A. Mainzer T. Grav J. Masiero E. Hand J. Bauer D. Tholen R. S. McMillan T. Spahr R. M. Cutri E. Wright J. Watkins W. Mo C. Maleszewski November 2011 NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...90M The Astrophysical Journal 741 2 25 2011ApJ...741...90M 10.1088/0004-637X/741/2/90 1109.6407 15 May 2016 Pravec, Petr Harris, Alan W. Kusnirák, Peter Galád, Adrián Hornoch, Kamil September 2012 Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012Icar..221..365P Icarus 221 1 365–387 2012Icar..221..365P 10.1016/j.icarus.2012.07.026 17 November 2015 6 Joseph R. Masiero A. K. Mainzer T. Grav J. M. Bauer R. M. Cutri C. Nugent M. S. Cabrera November 2012 Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M The Astrophysical Journal Letters 759 1 5 2012ApJ...759L...8M 10.1088/2041-8205/759/1/L8 1209.5794 15 May 2016 Wisniewski, W. Z. Michalowski, T. M. Harris, A. W. McMillan, R. S. March 1995 Photoelectric Observations of 125 Asteroids http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1995LPI....26.1511W Abstracts of the Lunar and Planetary Science Conference 26 1511 1995LPI....26.1511W 17 November 2015 Stephens, Robert D. September 2005 Asteroid lightcurve photometry from Santana Observatory - winter 2005 http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2005MPBu...32...66S The Minor Planet Bulletin 32 3 66–68 1052-8091 2005MPBu...32...66S 17 November 2015 Astronomer Tom Gehrels, 1925–2011 http://uanews.org/story/astronomer-tom-gehrels-1925-2011 https://web.archive.org/web/20141006102928/http://uanews.org/story/astronomer-tom-gehrels-1925-2011 usurped 6 October 2014 Jeff Harrison University of Arizona 12 July 2011 17 November 2015 6 Joseph R. Masiero T. Grav A. K. Mainzer C. R. Nugent J. M. Bauer R. Stevenson S. Sonnett August 2014 Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M The Astrophysical Journal 791 2 11 2014ApJ...791..121M 10.1088/0004-637X/791/2/121 1406.6645 8 December 2016 Klinglesmith, Daniel A., III April 2017 Spin-Shape Model Lightcurves http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2017MPBu...44..127K The Minor Planet Bulletin 44 2 127–129 1052-8091 2017MPBu...44..127K 8 June 2017 External links Lightcurve plot of 1777 Gehrels, Palmer Divide Observatory, B. D. Warner (2005) 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 1777 1776 Kuiper 1777 1778 Alfvén 001777 4007 Category:Discoveries by Tom Gehrels Category:Discoveries by Cornelis Johannes van Houten Category:Discoveries by Ingrid van Houten-Groeneveld Category:Named minor planets 001777 19600924