Astronomy:26074 Carlwirtz
| Discovery [1] | |
|---|---|
| Discovered by | H.-E. Schuster |
| Discovery site | La Silla Obs. |
| Discovery date | 8 October 1977 |
| Designations | |
| (26074) Carlwirtz | |
| Named after | Carl Wilhelm Wirtz [1] (German astronomer) |
| 1977 TD · 1996 KH | |
| Minor planet category | Mars-crosser [2] · Hungaria [1] binary [3][4] |
| Orbital characteristics [2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 40.83 yr (14,913 d) |
| |{{{apsis}}}|helion}} | 1.9722 AU |
| |{{{apsis}}}|helion}} | 1.6499 AU |
| 1.8110 AU | |
| Eccentricity | 0.0890 |
| Orbital period | 2.44 yr (890 d) |
| Mean anomaly | 198.66° |
| Mean motion | 0° 24m 15.84s / day |
| Inclination | 31.613° |
| Longitude of ascending node | 102.81° |
| 73.302° | |
| Known satellites | 1 (D: n.a. km; P: 16.11 h)[4][lower-alpha 1] |
| Earth MOID | 0.7534 AU (294 LD) |
| Physical characteristics | |
| Mean diameter | 2.54 km (est.)[3] 3.62 km (est.)[4] |
| Rotation period | 2.5493±0.0003 h[5][lower-alpha 1] |
| Geometric albedo | 0.16 (assumed)[4] 0.30 (assumed)[3] |
| E (assumed)[3] | |
| Absolute magnitude (H) | 14.9[3] 15.0[1][2] |
26074 Carlwirtz (provisional designation 1977 TD) is a dynamical Hungaria asteroid and binary Mars-crosser from the innermost regions of the asteroid belt, approximately 3 kilometers (2 miles) in diameter. It was discovered on 8 October 1977, by German astronomer Hans-Emil Schuster at ESO's La Silla Observatory in northern Chile. The likely binary asteroid on a relatively circular orbit has a short rotation period of 2.5 hours.[3] It was named for German astronomer Carl Wilhelm Wirtz.[1] The system's suspected minor-planet moon of unknown size was first detected in 2013.[5]
Orbit and classification
Carlwirtz is a member of the Mars-crossing asteroids, a dynamically unstable group between the main belt and the near-Earth populations, crossing the orbit of Mars at 1.66 AU.[1][6] It also belongs to the dynamical Hungaria group, which forms the innermost dense concentration of asteroids in the Solar System.[3] It is, however, not a member of the Hungaria family (003), but a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[6][7]
It orbits the Sun in the innermost asteroid belt at a distance of 1.65–1.97 AU once every 2 years and 5 months (890 days; semi-major axis of 1.81 AU). Its orbit has an unusually low eccentricity of 0.09 and an inclination of 32° with respect to the ecliptic.[2] The body's observation arc begins at La Silla Observatory in October 1977, on the night following its official discovery observation.[1]
Naming
This minor planet was named after Carl Wilhelm Wirtz (1875–1939), a German astronomer at Strasbourg and Kiel observatories. In 1924, he revealed statistically the redshift-distance relationship of spiral nebulae. The official naming citation was published by the Minor Planet Center on 28 September 2004 (M.P.C. 52769).[8]
Physical characteristics
Carlwirtz is an assumed E-type asteroid,[3] but may as well be a common S-type asteroid, since the E-type is typical found among members of the Hungaria family rather than among the larger, encompassing dynamical group with the same name.
Rotation period
In June 2013, a rotational lightcurve of Carlwirtz was obtained from photometric observations by American photometrist Brian Warner at the Palmer Divide Station (U82) in California. Lightcurve analysis gave a well-defined rotation period of 2.5493±0.0003 hours with a brightness amplitude of 0.11±0.01 magnitude ({{{1}}}).[5][lower-alpha 1] Follow-up observations by Warner in May 2018 gave a similar period 2.539±0.002 hours ({{{1}}}).[3][lower-alpha 2]
Satellite
During the observations in June 2013, Warner also noted that Carlwirtz is likely a synchronous binary asteroid with a minor-planet moon in its orbit.[5][lower-alpha 1] While the satellite dimension could not be determined, it has an orbital period of 16.11 hours with an estimated semi-major axis of 6.1 kilometers.[4] However, neither in 2013 nor in the 2018-observations any eclipsing/occultation events could be detected. Instead the asteroid has a classically shaped bimodal lightcurve instead. Since Carlwirtz has a period that is close to two thirds of an Earth-day, single-station observations have difficulties to track a complete lightcurve.[3][5][lower-alpha 1][lower-alpha 2]
Diameter and albedo
The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 – a compromise value between the S-type (0.20) and E-type (0.40) asteroids – and calculates a diameter of 2.54 kilometers based on an absolute magnitude of 14.9.[3][5] According to estimates by Johnston's archive, Carlwirtz measures 3.62 kilometers in diameter for an assumed albedo of 0.16.
Notes
- ↑ 1.0 1.1 1.2 1.3 1.4 Lightcurve plot of (26074) Carlwirtz Warner (2013), at the Palmer Divide Station (U82). Primary rotation period: 2.5493±0.0003 hours. Secondary rotation period: 16.11±0.02 hours. Quality code is 3. Summary figures at the LCDB and CS3 website.
- ↑ 2.0 2.1 Warner (2018). Lightcurve plot of follow-up observation from May 2018 Quality code is 2+. Summary figures at the LCDB and CS3 website.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 "26074 Carlwirtz (1977 TD)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=26074. Retrieved 19 November 2018.
- ↑ 2.0 2.1 2.2 2.3 "JPL Small-Body Database Browser: 26074 Carlwirtz (1977 TD)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2026074. Retrieved 19 November 2018.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 "LCDB Data for (26074) Carlwirtz". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=26074%7CCarlwirtz. Retrieved 19 November 2018.
- ↑ 4.0 4.1 4.2 4.3 4.4 Johnston, Wm. Robert (21 September 2014). "Asteroids with Satellites Database – (26074) Carlwirtz". Johnston's Archive. http://www.johnstonsarchive.net/astro/astmoons/am-26074.html. Retrieved 19 November 2018.
- ↑ 5.0 5.1 5.2 5.3 5.4 5.5 Warner, Brian D. (October 2013). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2013 May-June". The Minor Planet Bulletin 40 (4): 208–212. ISSN 1052-8091. Bibcode: 2013MPBu...40..208W. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2013MPBu...40..208W. Retrieved 19 November 2018.
- ↑ 6.0 6.1 "Asteroid 26074 Carlwirtz". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=26074+Carlwirtz. Retrieved 19 November 2018.
- ↑ "Asteroid (26074) Carlwirtz". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?n=26074&pc=1.1.6. Retrieved 25 May 2018.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html. Retrieved 19 November 2018.
External links
- Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
- Asteroid Lightcurve Database (LCDB), query form (info )
- Dictionary of Minor Planet Names, Google books
- Discovery Circumstances: Numbered Minor Planets (25001)-(30000) – Minor Planet Center
- 26074 Carlwirtz at AstDyS-2, Asteroids—Dynamic Site
- 26074 Carlwirtz at the JPL Small-Body Database
 |  |
