List of novae in 2018 explained

The following is a list of all novae that are known to have occurred in 2018. A nova is an energetic astronomical event caused by a white dwarf accreting matter from a star it is orbiting (typically a red giant, whose outer layers are more weakly attached than smaller, denser stars) Alternatively, novae can rarely be caused by a pair of stars merging with each other, however such events are vastly less common than novae caused by white dwarfs.

In 2018, 15 novae were discovered in the Milky Way, 14 being classical novae, and 1 being a dwarf nova of a previously known variable star, V392 Persei, which was discovered in 1972. An additional 23 novae were discovered in the Andromeda Galaxy, 8 in Messier 81, 1 in the Triangulum Galaxy, and 1 in Messier 83. A single luminous red nova was observed in NGC 45.

List of novae in 2018

In the Milky Way

Nova name	Discovery date	Constellation	Right ascension	Declination	Peak brightness (v)^[1]	Distance (light-years)	Absolute magnitude (v)	Nova type	Origin system identified?	Companion star spectral type^[2]
V357 Muscae^[3]	2018/01/14	Musca			6.5			Classical	Yes	F9V/G0V
V1661 Scorpii^[4]	2018/01/17	Scorpius			10.2	?	?	Classical	Yes	?
FM Circini^[5]	2018/01/19	Circinus			5.9			Classical	Yes	G1V
V1662 Scorpii^[6]	2018/02/06	Scorpius			10.1	?	?	Classical	Yes	?
V3664 Ophiuchi^[7]	2018/02/12	Ophiuchus			12.5			Classical	Yes	M0II/III
V1663 Scorpii^[8]	2018/02/24	Scorpius			12.3			Classical	Maybe	?
V3665 Ophiuchi^[9]	2018/03/10	Ophiuchus			9.4	?	?	Classical	Yes	?
V906 Carinae^[10]	2018/03/20	Carina			5.9			Classical	Yes	?
V435 Canis Majoris^[11]	2018/03/24	Canis Major			12.0	?	?	Classical	Maybe	?
V5857 Sagittarii^[12]	2018/04/08	Sagittarius			10.8	?	?	Classical	Yes	?
V392 Per^[13]	2018/04/29	Perseus			6.3	?	?	dwarf nova & nova	Yes	?
V408 Lupi^[14]	2018/06/03	Lupus			9.0			Classical	Maybe	K7V?
V613 Scuti^[15]	2018/06/29	Scutum			10.3	?	?	Classical	Yes	?
V3666 Ophiuchi^[16]	2018/08/08	Ophiuchus			9.0	?	?	Classical	No	?
V556 Normae^[17]	2018/10/13	Norma			10.2	?	?	Classical	Yes	?

In the Andromeda Galaxy

Novae are also frequently spotted in the Andromeda Galaxy, and are even slightly more commonly found than in the Milky Way, as there is less intervening dust to prevent their detection. Furthermore, Andromeda is circumpolar for observers north of latitude +48-50, roughly the latitude of the Canadian-American border, allowing observers north of that to search for transients all year.

In 2018, 23 novae were seen in the Andromeda galaxy.

Nova name	Discovery date	Right ascension	Declination	Peak brightness (v)	Absolute magnitude (v)
PNV J00444425+4142449	2018/01/10			18.4	-6.1
PNV J00431577+4118393	2018/01/12			17.8	-6.7
PNV J00423439+4044255	2018/02/07			16.7	-7.8
PNV J00415059+4125499	2018/02/22			17.9	-6.6
PNV J00424041+4112522	2018/03/21			18.1	-6.4
PNV J00425509+4119009	2018/04/03			17.6	-6.9
PNV J00421895+4113524	2018/04/19			16.9	-7.6
PNV J00415353+4114121	2018/04/29			17.5	-7.0
PNV J00434212+4122349	2018/05/19			17.0	-7.5
PNV J00424144+4117377	2018/06/26			17.1	-7.4
PNV J00414889+4109148	2018/07/01			17.4	-7.1
PNV J00420765+4119438	2018/07/12			17.3	-7.2
PNV J00425261+4118409	2018/07/15			18.6	-5.9
PNV J00425074+4115461	2018/07/31			19.1	-5.4
PNV J00424214+4114457	2018/08/02			17.5	-7.0
PNV J00392190+4015488	2018/08/13			19.0	-5.5
PNV J00451587+4210269	2018/08/21			17.9	-6.6
PNV J00424990+4123348	2018/10/11			17.9	-6.6
PNV J00424012+4117273	2018/10/13			17.5	-7.0
TCP J00420310+4102331	2018/10/15			18.0	-6.5
PNV J00424065+4111080	2018/12/03			18.7	-5.8
PNV J00424241+4119411	2018/12/17			18.2	-6.3
PNV J00432462+4120222	2018/12/22			18.0	-6.5
PNV J00424380+4117208	2018/12/23			17.5	-7.0

In other galaxies

Any galaxy within 20 million light-years of the Sun could theoretically have nova events bright enough to be detected from Earth, although in practice most are only detected in galaxies within 10-15 million light-years of the Milky Way, such as the Triangulum Galaxy, Messier 81, Messier 82, Messier 83, and Messier 94.

In 2018, of the ten novae observed in other galaxies than the Milky Way or the Andromeda Galaxy, eight were in Messier 81, with the remaining two from the Triangulum Galaxy and Messier 83. A luminous red nova, probably caused by the merger of two stars, occurred in NGC 45.

Nova name	Discovery date	Host galaxy	Right ascension	Declination	Peak brightness (v)	Distance (million light-years)	Absolute magnitude (v)	Type
PNV J13370978-2956576	2018/01/28	Messier 83			20.7	15.2	-7.6	Classical
PNV J09555926+6903517	2018/01/30	Messier 81			20.3	11.5	-7.4	Classical
PNV J09545236+6904085	2018/02/19	Messier 81			20.0	11.5	-7.7	Classical
PNV J09553607+6902141	2018/03/06	Messier 81			20.8	11.5	-6.9	Classical
PNV J09551340+6900478	2018/03/20	Messier 81			21.2	11.5	-6.5	Classical
PNV J09553194+6909147	2018/04/02	Messier 81			20.4	11.5	-7.3	Classical
PNV J09555269+6858409	2018/04/09	Messier 81			20.6	11.5	-7.1	Classical
AT 2018bwo	2018/05/22	NGC 45			16.4	32.6	-13.6	Luminous Red Nova
PNV J09560988+6859108	2018/10/12	Messier 81			20.1	11.5	-7.6	Classical
PNV J01334673+3032181	2018/10/13	Triangulum Galaxy			18.1	2.65	-6.4	Classical
PNV J09555246+6902009	2018/11/06	Messier 81			20.0	11.5	-7.7	Classical

See also

• List of novae in 2019
• Nova
• Dwarf nova
• Luminous red nova
• Guest star (astronomy)
• Supernova

External links

• List of all galactic novae

Notes and References

1. Web site: Mukai . Koji . Recent Novae . asd.gsfc.nasa.gov . 25 January 2019.
2. In most cases, the spectral type is estimated based on the absolute magnitude
3. Web site: CBET 4473: 20180117 : NOVA MUSCAE 2018 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
4. Web site: CBET 4481: 20180130 : NOVA SCORPII 2018 = PNV J17180658-3204279 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
5. Web site: CBET 4482: 20180130 : NOVA CIRCINI 2018 = PNV J13532700-6725110 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
6. Web site: CBET 4488: 20180212 : NOVA SCORPII 2018 No. 2 = PNV J16484962-4457032 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
7. Web site: CBET 4489: 20180225 : NOVA IN OPHIUCHUS = PNV J17244011-2421463 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
8. Web site: Stanek . K. Z . ATel #11348: ASAS-SN Discovery of a Possible Galactic Nova ASASSN-18ds . ATel . 25 January 2019.
9. Web site: CBET 4492: 20180312 : NEW NOVA IN OPHIUCHUS = TCP J17140253-2849233 = PNV J17140261-2849237 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
10. Web site: CBET 4498: 20180322 : NOVA CARINAE 2018 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
11. Web site: CBET 4499: 20180325 : NOVA CANIS MAJORIS 2018 = TCP J07134590-2112330 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
12. Web site: CBET 4507: 20180412 : NOVA IN SAGITTARIUS = PNV J18040967-1803581 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
13. Web site: V0392 Per . International Variable Star Index . AAVSO . 17 January 2021.
14. Web site: CBET 4520: 20180605 : NOVA LUPI 2018 = PNV J15384000-4744500 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
15. Web site: CBET 4530: 20180703 : NOVA SCUTI 2018 = TCP J18292290-1430460 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
16. Web site: CBET 4540: 20180813 : NEW NOVA IN OPHIUCHUS = PNV J17422408-2053088 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.
17. Web site: CBET 4568: 20181026 : NOVA NORMAE 2018 = PNV J16143400-5330050 . Central Bureau for Astronomical Telegrams . IAU . 25 January 2019.