444 Gyptis

{{Short description|Main-belt asteroid}}

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

{{Infobox planet

| minorplanet=yes

| background=#D6D6D6

| name=444 Gyptis

| discoverer=Jérôme Eugène Coggia

| discovered=31 March 1899

| mpc_name=(444) Gyptis

| alt_names=1899 EL

| pronounced={{IPAc-en|'|dZ|I|p|t|I|s}}

| named_after=Gyptis

| adjective = Gyptidian

| mp_category=Main belt

| epoch=31 July 2016 (JD 2457600.5)

| semimajor={{Convert|2.77005|AU|Gm|abbr=on}}

| perihelion={{Convert|2.28337|AU|Gm|abbr=on}}

| aphelion={{Convert|3.25674|AU|Gm|abbr=on|lk=on}}

| eccentricity=0.17569

| period=4.61 yr (1684.0 d)

| inclination=10.2775°

| asc_node=195.716°

| arg_peri=154.984°

| mean_anomaly=11.8852°

| dimensions=179×150 km

| mean_diameter = {{val|159.331|0.490|ul=km}}{{cite web

|type=2024-09-25 last obs

|title=JPL Small-Body Database Browser: 444 Gyptis (1899 EL)

|url=https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=444

|access-date=19 Dec 2024}}
{{val|164.63|2.60|ul=km}}

| mass=1.25{{e|19}} kg

{{cite web

|date=2008

|title=Recent Asteroid Mass Determinations

|publisher=Personal Website

|author=Jim Baer

|url=http://home.earthlink.net/~jimbaer1/astmass.txt

|access-date=2008-11-27

|archive-url=https://web.archive.org/web/20130702212735/http://home.earthlink.net/~jimbaer1/astmass.txt

|archive-date=2013-07-02

|url-status=dead

}}

{{val|1.06|0.28|e=19|u=kg}}

| density=5.53±1.46 g/cm³
{{val|4.55|1.23|u=g/cm3}}

| rotation={{Convert|6.214|h|d|abbr=on|lk=on}}

| spectral_type=C

| abs_magnitude=8.07

| albedo={{val|0.051|0.008}}

| mean_motion={{Deg2DMS|0.213782|sup=ms}} / day

| orbit_ref=

| observation_arc=116.54 yr (42568 d)

| uncertainty=0

}}

444 Gyptis is a main-belt asteroid that was discovered by Jérôme Eugène Coggia on March 31, 1899, in Marseille. It is classified as a C-type asteroid and is probably composed of carbonaceous material. The spectra of the asteroid displays evidence of aqueous alteration.

In 2004, Kochetova estimated Gyptis to have a mass of 1.25{{e|19}} kg with a high density of 5.53 g/cm³. In 2012 Carry estimated the mass as {{val|1.06|0.28|e=19|u=kg}} with a high density of {{val|4.55|1.23|u=g/cm3}}. The adaptive optics instrument at the W. M. Keck Observatory showed an object with a diameter of 129 km, which is much smaller than the estimate of 160 km from the IRAS observatory measurements, indicating an irregular shape. The size ratio between the major and minor axes is estimated at 1.40. Observations of an occultation on October 14, 2007, produced six chords indicating a cross-section ellipsoid of 179×150 km.{{cite web|date=2007-10-14|title=2007 European Asteroidal Occultation Results|publisher=euraster.net (a website for Asteroidal Occultation Observers in Europe)|url=http://www.euraster.net/results/2007/index.html#1014-444|access-date=2008-12-01}} [http://www.euraster.net/results/2007/20071014-Gyptis-crd.gif (Chords)]

Between 1990 and 2021, 444 Gyptis has been observed to occult 17 stars.