Using deep UK Schmidt telescope (UKST), a team of astronomers have found and confirmed six new planetary nebulae in a neighbor galaxy, the Small Magellanic Cloud.
When a low or intermediate mass star (roughly 0.3 ÷ 8 the mass of the sun) nearing the end of its lifetime, it swells up into a red giant, expanding and create a beautiful shell of diffuse gas known as a planetary nebula. There are at least 10,000 planetary nebulae in our galaxy although only about 1,500 have been detected. In 5 billion years, our sun will become a red giant expanding out beyond the orbit of Venus engulfing the inner planets, possibly even Earth, eventually the helium in its core runs out and fusion stops thus the outer layers of it are blown off in huge clouds of gas and dust creating a beautiful nebulae.
Planetary nebulae (PNe) play a crucial role in understanding mass loss for low and intermediate mass stars, they influence chemical evolution of galaxies by expelling elements to the interstellar medium from stars where those elements were created, they are a major Galactic dust factory.
The Small Magellanic Cloud is a gas rich, dwarf and irregular galaxy orbiting the Milky Way galaxy (satellite to our galaxy). It is about 7,000 light-years across contains several hundred million stars and only 100 known population of Planetary nebulae. Due to its proximity to our galaxy, it can be easily studied in its entirety. It’s reddening and extinction is relatively low and uniform, enabling absolute nebula luminosity estimates.
In a new study uploaded on arxiv servers, Australian astronomers have found and confirmed the spectra of six preliminary PNe candidates, discoveries which provide a 6% increase to the previously known Small Magellanic Cloud PN population of ∼100.
Once spectroscopic follow-up of all our newly identified candidates is complete, we expect to increase the total number of known SMC PNe by up to 50%.
said Danica Draskovic, Department of Physics and Astronomy, Macquarie University, NSW, Australia.
This discovery will have a major impact on improving rates of elemental enhancement in lower mass stars within a low-metallicity environment also its enable further insights into the chemical evolution and kinematics of the small magellanic cloud PN population.