99P/Kowal

{{Short description|Periodic comet}}

{{Use dmy dates|date=May 2025}}

{{Infobox comet

| name = 99P/Kowal

| image =

| caption =

| discovery_ref = {{r|IAUC_3066}}

| discoverer = Charles T. Kowal

| discovery_site = Palomar Observatory

| discovery_date = 24 April 1977

| mpc_name = P/1977 H2
P/1991 D2

| designations = {{unbulleted|Kowal 1|1977 III, 1992 VI|1977f, 1991i}}

| orbit_ref = {{r|jpldata|MPC}}

| epoch = 17 October 2024 (JD 2460600.5)

| observation_arc = 47.25 years

| obs = 1,740

| perihelion = 4.702 AU

| aphelion = 7.489 AU

| semimajor = 6.095 AU

| eccentricity = 0.22857

| period = 15.049 years

| inclination = 4.339°

| asc_node = 28.083°

| arg_peri = 174.59°

| mean = 60.356°

| tjup = 2.956

| Earth_moid = 3.724 AU

| Jupiter_moid = 0.307 AU

| physical_ref = {{r|jpldata}}

| mean_diameter = {{cvt|10.2|km|mi}}

| M1 = 6.7

| M2 = 11.5

| last_p = 12 April 2022

| next_p = 6 May 2037{{r|Horizons2029}}

}}

99P/Kowal, also known as Kowal 1, is a periodic comet in the Solar System that orbits out by Jupiter and has a 15 year orbital period. It has been observed regularly since 2019. Its most recent perihelion occurred in April 2022, and is expected to return by May 2037.{{r|MPC}}

Observational history

Charles T. Kowal discovered this comet shortly after reporting the discovery of asteroid 2063 Bacchus (then known as 1977 HB) on the night of 24 April 1977.{{r|IAUC_3066}} It already passed perihelion when it was first spotted as a 16th-magnitude object within the constellation Virgo.{{r|cometography}} Orbital calculations by Shuichi Nakano and Brian G. Marsden predicted that the comet has a 15-year orbit around the Sun, and was expected to return by 1992.{{r|cometography}} It was successfully recovered by James V. Scotti from the Kitt Peak Observatory's Spacewatch program on 21 February 1991.{{r|IAUC_5195}}

Between 12 and 14 May 2021, a small outburst temporarily brightened Comet Kowal 1, which raised its apparent magnitude from 18.32 to 17.6.{{r|Kelley_2021}}

References

{{Reflist|refs=

{{cite web

| author1= G. W. Kronk

| title= 99P/Kowal 1

| url= https://cometography.com/pcomets/099p.html

| website= Cometography.com

| access-date= 26 May 2025 }}

{{cite web

| title= Horizons Batch for 99P/Kowal 1 (90000934) on 2037-May-06

| publisher= JPL Horizons

| type= Perihelion occurs when rdot flips from negative to positive

| url= https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D99P%3BCAP%27&START_TIME=%272037-May-03%27&STOP_TIME=%272037-May-09%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27

| access-date= 6 July 2023 }} (JPL#65 Soln.date: 2023-Jul-05)

{{cite journal

| author1= C. T. Kowal

| editor1= B. G. Marsden

| title= Comet Kowal (1977f)

| url= http://www.cbat.eps.harvard.edu/iauc/03000/03066.html#Item2

| website= IAU Circular

| date= 26 April 1991

| volume= 3066

| issue= 2

| bibcode= 1977IAUC.3066....2K }}

{{cite journal

| author1= J. V. Scotti

| author2= B. G. Marsden

| editor1= D. W. Green

| title= Periodic Comet Kowal 1 (1991i)

| url= http://www.cbat.eps.harvard.edu/iauc/05100/05195.html

| journal= IAU Circular

| date= 23 February 1991

| volume= 5195

| issue= 1

| bibcode= 1991IAUC.5195....1S }}

{{cite web

| title= 99P/Kowal 1 – JPL Small-Body Database Lookup

| url= https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=99P

| website= ssd.jpl.nasa.gov

| publisher= Jet Propulsion Laboratory

| access-date= 25 May 2025 }}

{{cite journal

| author1= M. S. P. Kelley

| title= Small Apparent Outburst of Comet 99P/Kowal 1

| url= https://www.astronomerstelegram.org/?read=14628

| journal= The Astronomer's Telegram

| date= 14 May 2021

| volume= 14628

| bibcode= 2021ATel14628....1K }}

{{cite web

| title= 99P/Kowal Orbit

| url= http://www.minorplanetcenter.net/db_search/show_object?object_id=99P

| publisher= Minor Planet Center

| access-date= 24 February 2019 }}

}}