NGC 2547 is a southern

open cluster An open cluster is a type of star cluster made of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and ...

in Vela, discovered by

Nicolas Louis de Lacaille Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a French astronomer and geodesist who named 14 out of the 88 constellations. From 1750 to 1754, he studied the sky at the Cape of Good ...

in 1751 from South Africa. The star cluster is young with an age of 20-30 million years. Observations with the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...

showed a shell around the B3 III/IV-type star HD 68478. This could be a sign of recent mass loss in this star. A study using

Gaia In Greek mythology, Gaia (; from Ancient Greek , a poetical form of , 'land' or 'earth'),, , . also spelled Gaea , is the personification of the Earth and one of the Greek primordial deities. Gaia is the ancestral mother—sometimes parthenog ...

DR2 data showed that NGC 2547 formed about 30 million years ago together with a new discovered star cluster, called BJ20186. The star cluster NGC 2547 has a similar age compared with

Trumpler 10 Trumpler 10 (also known as C 0846-423) is an open cluster located in the constellation Vela. It was possibly discovered by Nicolas Louis de Lacaille in 1751-52, as the cluster's location data matches well with No. II.6 in his catalog. The clust ...

, NGC 2451B, Collinder 135 and Collinder 140. It was suggested that all these clusters formed in a single event of triggered star formation. NGC 2547 shows evidence for

mass segregation In astronomy, dynamical mass segregation is the process by which heavier members of a gravitationally bound system, such as a star cluster, tend to move toward the center, while lighter members tend to move farther away from the center. Equipar ...

down to 3 .

Cluster members with debris disks

Observations with the

have shown that ≤1% of the stars in NGC 2547 have infrared excess in 8.0 μm and 30-45% of the B- to F-type stars have infrared excess at 24 μm. The system 2MASS J08090250-4858172, also called ID8 is located in NGC 2547 and showed substantial brightening of the

debris disk A debris disk (American English), or debris disc (Commonwealth English), is a circumstellar disk of dust and debris in orbit around a star. Sometimes these disks contain prominent rings, as seen in the image of Fomalhaut on the right. Debris dis ...

at a wavelength of 3 to 5 micrometers, followed by a decay over a year. This was interpreted as a violent

impact Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impac ...

on a

planetary body A planetary-mass object (PMO), planemo, or planetary body is by geophysical definition of planet, geophysical definition of celestial objects any celestial object massive enough to achieve hydrostatic equilibrium (to be rounded under its own gra ...

in this system. NGC 2547 contains nine M-dwarfs with 24 μm excess. These could be

s and the material could be orbiting close to the

snow line The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...

of these stars, indicating that planet-formation is underway in these systems. Later it was suggested that these M-dwarfs might contain

Peter Pan Disk A Peter Pan disk is a circumstellar disk around a star or brown dwarf that appears to have retained enough gas to form a gas giant planet for much longer than the typically assumed gas dispersal timescale of approximately 5 million years. Several ...

s. 2MASS 08093547-4913033, which is one of the M-dwarfs with a debris disk in NGC 2547 was observed with the Spitzer Infrared Spectrograph. In this system the first detection of

silicate In chemistry, a silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is al ...

was made from a debris disk around an M-type star.

Gallery

References

External links

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SEDS
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