V1280 Scorpii (or Nova Scorpii 2007 Number 1) is the first of two

novae A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramati ...

that occurred in the constellation

Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation that pre-dates the Gre ...

during February 2007 (the second nova was the fainter V1281 Scorpii, which was discovered on 19 February 2007). Announced by the

IAU The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...

in Electronic Telegram No. 835 and Circular No. 8803, the nova's

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

was 9.6 when it was discovered on CCD images taken at 20:42 UT on 4 February 2007 by Yuji Nakamura of

Kameyama, Mie 260px, Seki-juku (Tōkaidō) is a city located in northern Mie Prefecture, Japan. , the city had an estimated population of 49,457 in 21,745 households and a population density of 260 persons per km². The total area of the city is . Geograp ...

, Japan. It was independently discovered on the same night at 20:30 UT by Yukio Sakurai of

Mito, Ibaraki is the capital city of Ibaraki Prefecture, in the northern Kantō region of Japan. , the city had an estimated population of 269,330 in 123,282 households and a population density of 1239 persons per km2. The percentage of the population aged o ...

, Japan. It peaked at magnitude 3.79 on February 17, making it easily visible to the naked eye. V1280 Scorpii is two degrees south of M62. V1280ScoLocation

The early period after V1280 Scorpii's eruption was observed in great detail by the Solar Mass Ejection Imager (SMEI) instrument on the Coriolis satellite. This satellite obtained a brightness value for the nova every 102 minutes. The rise to peak brightness was exceptionally slow. The SMEI light curve shows three well defined maxima for the nova, occurring around 03:00 UT on 16 February, 08:30 UT on 17 February and 05:00 UT on 19 February 2007. The nova declined slowly from peak brightness until the end of February 2007, at which time it began fading rapidly as dust formed in the ejected material. At the same time dust formation was causing the visual light curve to plummet, the infrared brightness increased. The formation of V1280 Scorpii's dusty structure was observed in the near ( K-band) and mid (

N band N, or n, is the fourteenth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''en'' (pronounced ), plural ''ens''. History ...

) infrared by the VLT interferometer, and the interferometer was able to measure the expansion of the dust shell. These were the first such observations for any nova. On day 100, another brightening was observed, which corresponded to a second mass loss event. The expanding dust shell around the nova has an estimated velocity of 350 km/s. The mass of the nova's white dwarf has been estimated to be 0.6 , based on the SMEI light curve. The morphology of V1280 Scorpii's

nova remnant A nova remnant is made up of the material either left behind by a sudden explosive fusion eruption by classical novae, or from multiple ejections by recurrent novae. Over their short lifetimes, nova shells show expansion velocities of around 1000& ...

is complex, but overall bipolar in shape; on either sides of the nova are outflows emitting

forbidden line In spectroscopy, a forbidden mechanism (forbidden transition or forbidden line) is a spectral line associated with absorption or emission of photons by atomic nuclei, atoms, or molecules which undergo a transition that is not allowed by a particu ...

s of

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...

(O III) and

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

(N II). Surrounding the center is an equatorial torus of dust, which variably blocks light.

References

External links

AAVSO announcementAAVSO quick-look data
* {{Novae Novae Scorpius (constellation) 20070206 Scorpii, V1280