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Deep Sky Observer's Companion – the online database

 

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Ancient open cluster in Lyra

Greek astrophotographer Anthony Ayiomamitis recently imaged the old open cluster NGC 6791 in Lyra. He writes:

"NGC 6791 is not only well-known but also well-studied, for it is one of the oldest open clusters discovered so far and whose age has been estimated to be as high as 10.2 billion years-old (2004 study) and which would make it more than twice the age of the solar system.

"A recent study using HST images revelead three sets of member stars comprised of white dwarfs aged 4 and 6 billion years-old whereas the third (non-dwarf) group was determined to be 8 billion years-old.

"Anyone who has tried to image NGC 6791 knows very well how dim this open cluster is and the difficulty involved in getting it to stand out from the background sky. NGC 6791 is comprised of 10,000 member stars and lies 13,300 light-years away.

"Another open cluster with a very similar storyline is NGC 188 near the northern polar region and which I also plan to revisit over the next few days."

Anthony's image is the result of a total of three hours of exposure; it can be enjoyed in high resolution at http://www.perseus.gr/Astro-DSO-NGC-6791.htm.

NGC 6791, imaged by Anthony Ayiomamitis.

Recent news

top story: March newsletter of the ASSA Deep-Sky Section, featuring 47 Tuc on the cover. — "Nightfall" (2015 April) is the current newsletter of the Deep-Sky Observing Section of the Astronomical Society of Southern Africa.

A globular cluster in the realm of the galaxies — A rare gem - a bright globular cluster in the realm of the galaxies.

The Dark Emu rises, in pursuit of the Magellanic Clouds — The beautiful complex of dark nebulosity along the southern Milky Way appears like an ancient monster, its serpentine neck reaching out as if to gobble up the Magellanic Clouds.

Massive star forming region in the Small Magellanic Cloud — Dale Liebenberg images NGC 346, a gigantic star forming region in the SMC.

Flocculent Galaxy in Southern Leo — Dale Liebenberg images the spiral galaxy NGC 3521 in southern Leo.

Ancient open cluster in Lyra — Anthony Ayiomamitis images the old open cluster NGC 6791.

Golden Coin Galaxy — Dale Liebenberg images the Golden Coin, NGC 4945 in Centaurus.

NGC 2467 in Puppis — Dale Liebenberg images NGC 2467 in Puppis.

Last but not least - Messier 103 — Anthony Ayiomamitis images Messier 103 in Cassiopeia.

The Arkenstone of Thrain — Dale Liebenberg images Messier 22, the "Arkenstone of Thrain" according to Burnham.

ConCards available — A handy set of beginner's star charts, "Constellation Cards" are now available for free download.

Deep sky celebrations — Three deep sky observers of yore have birthdays this week: William Herschel (1738), the Fourth Earl of Rosse, and Stephane Javelle.

Necklace Nebula featured on APOD — The recently-discovered planetary nebula nicknamed the Necklace Nebula, recently featured on APOD.

Methuselah Nebula featured on APOD — The old bipolar planetary nebula MWP1, a.k.a. Methuselah Nebula, is today's APOD.

New deepsky book from CUP — Deep sky author Wolfgang Steinicke's latest book, "Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer's New General Catalogue", has just been published by Cambridge University Press.

NGC 1365 in infrared (ESO VLT) — The bright barred spiral galaxy NGC 1365 in Fornax has been imaged in the infrared with the ESO VLT telescope.

New HST image of eta Carinae Nebula — New observations, combined with images made in 2005, show beautiful detail in part of the extensive eta Carinae Nebula.

First planetary in open cluster found — A team of astronomers from Australia, the UK, the USA and France have discovered the first planetary nebula known to be associated with a galactic open cluster.

NGC 300 in Sculptor imaged at ESO — The bright spiral galaxy NGC 300 has been imaged with the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile.

Superwind galaxy NGC 4666 — A remarkable galaxy with very vigorous star formation has been newly imaged on the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile.

News archives

All earlier news items can be browsed in the archives.

Quote

As stargazers we should practice what Lee Cains calls ‘the serene art of visual observing.’ We must learn to see with the mind as well as the eye. This means really examining and contemplating the varied scenes before us in the eyepiece. All deep sky objects deserve at least 15 minutes of your time. Glancing at an object once it’s found and then rushing to another and another is like reading only the Cliff’s Notes of the world’s great novels.
James Mullaney

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Everything on DOCdb.net is © 2004-2010 by Auke Slotegraaf, unless stated otherwise or if you can prove you have divine permission to use it. Before using material published here, please consult the Creative Commons Attribution-Non-Commercial-Share Alike 2.5 License. Some material on DOCdb is copyright the individual authors. If in doubt, don't reproduce. And that goes for having children, too. Please note that the recommended browser for DOCdb is Firefox 3.x. You may also get good results with K-Meleon. Good luck if you're using IE. A successful experience with other browsers, including Opera and Safari, may vary.