19741 Callahan

{{Short description|Main-belt asteroid}}

{{Use dmy dates|date=October 2019}}

{{Infobox planet

| minorplanet = yes

| name = 19741 Callahan

| background = #D6D6D6

| image =

| image_size =

| caption =

| discovery_ref =

| discovered = 5 January 2000

| discoverer = LINEAR

| discovery_site = Lincoln Lab ETS

| mpc_name = (19741) Callahan

| alt_names = {{nowrap|{{mp|2000 AN|141}}{{·}}{{mp|1978 RQ|8}}}}

| named_after = Diane Callahan
{{small|(mentor at DCYSC)}}

| mp_category = main-belt{{·}}{{small|(inner)}}
background

| orbit_ref =

| epoch = 4 September 2017 (JD 2458000.5)

| uncertainty = 0

| observation_arc = 38.66 yr (14,121 days)

| aphelion = 2.5407 AU

| perihelion = 1.9559 AU

| semimajor = 2.2483 AU

| eccentricity = 0.1301

| period = 3.37 yr (1,231 days)

| mean_anomaly = 163.76°

| mean_motion = {{Deg2DMS|0.2924|sup=ms}} / day

| inclination = 8.0506°

| asc_node = 167.39°

| arg_peri = 227.28°

| dimensions = 3.12 km {{small|(calculated)}}
{{val|3.876|0.166}} km

| rotation = {{val|7.2684|0.0015}} h

| albedo = 0.20 {{small|(assumed)}}
{{val|0.224|0.044}}

| spectral_type = S

| abs_magnitude = 14.3{{·}}14.4{{·}}{{val|14.444|0.004}}{{·}}14.89

}}

19741 Callahan (provisional designation {{mp|2000 AN|141}}) is a stony background asteroid from the inner regions of the asteroid belt, approximately 3.5 kilometers in diameter.

It was discovered on 5 January 2000, by the Lincoln Near-Earth Asteroid Research, LINEAR, at the Lincoln Laboratory's Experimental Test Site, Socorro, New Mexico, and named after a mentor of the 2003 Discovery Channel Young Scientist Challenge.

Orbit and classification

The S-type asteroid orbits the Sun in the inner main-belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,231 days). Its orbit has an eccentricity of 0.13 and an inclination of 8° with respect to the ecliptic. Callahan was first identified as {{mp|1978 RQ8}} at ESO's La Silla Observatory in 1978, which extends the asteroid's observation arc by 22 years prior to its official discovery observation.

Physical characteristics

In December 2009, a rotational lightcurve for this asteroid was obtained from photometric observations at the U.S. Palomar Transient Factory, California. It gave a rotation period of {{val|7.2684|0.0015}} hours with a relatively high brightness variation of 0.81 in magnitude ({{small|U=2}}), indicative of a non-spherical shape.

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Callahan measures 3.9 kilometers in diameter and its surface has an albedo of 0.22. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 3.1 kilometers, with an absolute magnitude of 14.89.

Naming

This minor planet was named after Diane Callahan, teacher at U.S. Fairfield Middle School, Ohio, who mentored a finalist in the 2003 Discovery Channel Youth Science Challenge (DCYSC), a middle school science competition. The approved naming citation was published by the Minor Planet Center on 10 October 2003 ({{small|M.P.C. 49772}}).

References

{{reflist|refs=

{{cite web

|type = 2017-05-01 last obs.

|title = JPL Small-Body Database Browser: 19741 Callahan (2000 AN141)

|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2019741

|publisher = Jet Propulsion Laboratory

|access-date = 5 July 2017}}

{{cite book

|title = Dictionary of Minor Planet Names – (19741) Callahan, Addendum to Fifth Edition: 2003–2005

|last = Schmadel | first = Lutz D.

|publisher = Springer Berlin Heidelberg

|page = 142

|date = 2006

|isbn = 978-3-540-34360-8

|doi = 10.1007/978-3-540-34361-5_1597 |chapter = (19741) Callahan [2.25, 0.13, 8.0] }}

{{cite web

|title = 19741 Callahan (2000 AN141)

|work = Minor Planet Center

|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=19741

|access-date = 22 March 2016}}

{{cite web

|title = MPC/MPO/MPS Archive

|work = Minor Planet Center

|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html

|access-date = 17 May 2016}}

{{cite web

|title = LCDB Data for (19741) Callahan

|publisher = Asteroid Lightcurve Database (LCDB)

|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=19741%7CCallahan

|access-date = 17 May 2016}}

{{cite journal

|display-authors = 6

|first1 = A. |last1 = Mainzer

|first2 = T. |last2 = Grav

|first3 = J. |last3 = Masiero

|first4 = E. |last4 = Hand

|first5 = J. |last5 = Bauer

|first6 = D. |last6 = Tholen

|first7 = R. S. |last7 = McMillan

|first8 = T. |last8 = Spahr

|first9 = R. M. |last9 = Cutri

|first10 = E. |last10 = Wright

|first11 = J. |last11 = Watkins

|first12 = W. |last12 = Mo

|first13 = C. |last13 = Maleszewski

|date = November 2011

|title = NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...90M

|journal = The Astrophysical Journal

|volume = 741

|issue = 2

|page = 25

|bibcode = 2011ApJ...741...90M

|doi = 10.1088/0004-637X/741/2/90

|arxiv = 1109.6407

|access-date= 17 May 2016}}

{{cite journal

|display-authors = 6

|first1 = Adam |last1 = Waszczak

|first2 = Chan-Kao |last2 = Chang

|first3 = Eran O. |last3 = Ofek

|first4 = Russ |last4 = Laher

|first5 = Frank |last5 = Masci

|first6 = David |last6 = Levitan

|first7 = Jason |last7 = Surace

|first8 = Yu-Chi |last8 = Cheng

|first9 = Wing-Huen |last9 = Ip

|first10 = Daisuke |last10 = Kinoshita

|first11 = George |last11 = Helou

|first12 = Thomas A. |last12 = Prince

|first13 = Shrinivas |last13 = Kulkarni

|date = September 2015

|title = Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015AJ....150...75W

|journal = The Astronomical Journal

|volume = 150

|issue = 3

|page = 35

|bibcode = 2015AJ....150...75W

|doi = 10.1088/0004-6256/150/3/75

|arxiv = 1504.04041

|access-date= 17 May 2016}}

{{cite journal

|display-authors = 6

|first1 = Joseph R. |last1 = Masiero

|first2 = A. K. |last2 = Mainzer

|first3 = T. |last3 = Grav

|first4 = J. M. |last4 = Bauer

|first5 = R. M. |last5 = Cutri

|first6 = J. |last6 = Dailey

|first7 = P. R. M. |last7 = Eisenhardt

|first8 = R. S. |last8 = McMillan

|first9 = T. B. |last9 = Spahr

|first10 = M. F. |last10 = Skrutskie

|first11 = D. |last11 = Tholen

|first12 = R. G. |last12 = Walker

|first13 = E. L. |last13 = Wright

|first14 = E. |last14 = DeBaun

|first15 = D. |last15 = Elsbury

|first16 = T. IV |last16 = Gautier

|first17 = S. |last17 = Gomillion

|first18 = A. |last18 = Wilkins

|date = November 2011

|title = Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M

|journal = The Astrophysical Journal

|volume = 741

|issue = 2

|page = 20

|bibcode = 2011ApJ...741...68M

|doi = 10.1088/0004-637X/741/2/68

|arxiv = 1109.4096

|access-date= 3 December 2016}}

}}