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Dear Group,
I have located a paper from Astronomy & Astrophysics which identified some of the oldest open clusters in our galaxy. I was wondering if someone knows of a source which is after 2004 and which would be more recent (not that I am complaining that 2004 is outdated but just in case there is something more recent which I could not locate). For anyone interested as to the 2004 source, enjoy: http://www.mpa-garching.mpg.de/~weiss/aa_414_163.pdf ..... having already imaged M67 and NGC 188, I would like to pursue these older clusters further with a web page dedicated to them and which is already under construction. Thanks in advance! Anthony. |
#2
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Anthony check this
http://www.univie.ac.at/webda/descri...#cluster_level Vossinakis Andreas Thessaloniki, Greece |
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Vossinakis Andreas wrote:
Anthony check this http://www.univie.ac.at/webda/descri...#cluster_level Andrea, thanks for the link .... this is a VERY good source! Anthony. Vossinakis Andreas Thessaloniki, Greece |
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On Feb 26, 8:21 am, Anthony Ayiomamitis
wrote: Vossinakis Andreas wrote: Anthony check this http://www.univie.ac.at/webda/descri...#cluster_level Andrea, thanks for the link .... this is a VERY good source! Anthony. Vossinakis Andreas Thessaloniki, Greece- Hide quoted text - - Show quoted text - Anthony, The oldest cluster (by spectrometry) is Berkely 17 in Auriga about 05 21 + 30 40, and is currently observable. It is not an overwhelming object but is rather ominous when you consider that it checks out between 10 and 13 billion years in age. Ben 90.126 n 35.539 |
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Ben wrote:
On Feb 26, 8:21 am, Anthony Ayiomamitis wrote: Vossinakis Andreas wrote: Anthony check this http://www.univie.ac.at/webda/descri...#cluster_level Andrea, thanks for the link .... this is a VERY good source! Anthony. Vossinakis Andreas Thessaloniki, Greece- Hide quoted text - - Show quoted text - Anthony, Hi Ben, The oldest cluster (by spectrometry) is Berkely 17 in Auriga about 05 21 + 30 40, and is currently observable. This cluster is on my "do now, ASAP" list ... please look for a result with the first available opportunity on my part (following the eclipse later this week so as not to have the lunar glare when imaging). It is not an overwhelming object but is rather ominous when you consider that it checks out between 10 and 13 billion years in age. I have done quite a bit of research the past few days in relation to this project and along the way I have read that it is a toss-up between Berkeley 17 and NGC 6791 in Lyra. Are you aware of any "definitive" study between the two or are we stuck with the ambiguity? Berkeley 17 has been estimated to be 10.06 or 10.08 billion years old (depending on source) whereas NGC 6791 has estimates as high as 10.20 billion yrs old. Anthony. Ben 90.126 n 35.539 |
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Anthony,
I don't think a definitive study on cluster ages will ever be possible. We will just have to content ourselves with those analogs ( analogia = proportions) furnished by spectography. If we could trace them back they would all vasish into primordial "knots" of gas and dust and defining the instants of origin would remain speculative. I have a lot of trouble seeing 6791 from my observation site. I have to wait untill it gets really high (ca. 70 deg) before I can make it out at all. Ben |
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On Feb 26, 10:43 am, Anthony Ayiomamitis
wrote: Are you aware of any "definitive" study between the two or are we stuck with the ambiguity? Berkeley 17 has been estimated to be 10.06 or 10.08 billion years old (depending on source) whereas NGC 6791 has estimates as high as 10.20 billion yrs old. Looking at the follow-up articles to Salaris, there is: Bragaglia, A. et al. 2006. BVI photometry of the very old open cluster Berkeley 17 http://adsabs.harvard.edu/cgi-bin/np...NRAS.368.1971B "We have obtained BVI CCD imaging of Berkeley 17, an anticentre open cluster that competes with NGC 6791 as the oldest known open cluster." Krusberg, Z.A.C.; Chaboyer, B. 2006. UBVI CCD Photometry of the Old Open Cluster Berkeley 17. http://adsabs.harvard.edu/cgi-bin/np...J....131.1565K "Berkeley 17 and NGC 6791 are the oldest open clusters, with ages of 10 Gyr." - Canopus56 |
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On Feb 26, 10:43 am, Anthony Ayiomamitis
wrote: Are you aware of any "definitive" study between the two or are we stuck with the ambiguity? Berkeley 17 has been estimated to be 10.06 or 10.08 billion years old (depending on source) whereas NGC 6791 has estimates as high as 10.20 billion yrs old. Looking at the follow-up articles to Salaris, there is: Bragaglia, A. et al. 2006. BVI photometry of the very old open cluster Berkeley 17 http://adsabs.harvard.edu/cgi-bin/np...NRAS.368.1971B "We have obtained BVI CCD imaging of Berkeley 17, an anticentre open cluster that competes with NGC 6791 as the oldest known open cluster." Krusberg, Z.A.C.; Chaboyer, B. 2006. UBVI CCD Photometry of the Old Open Cluster Berkeley 17. http://adsabs.harvard.edu/cgi-bin/np...J....131.1565K "Berkeley 17 and NGC 6791 are the oldest open clusters, with ages of 10 Gyr." - Canopus56 |
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On Feb 26, 5:53 am, Anthony Ayiomamitis
wrote: I was wondering if someone knows of a source which is after 2004 and which would be more recent (not that I am complaining that 2004 is outdated but just in case there is something more recent which I could not locate). Anthony, Looking at Salaris's paper in NASA/ADS: http://adsabs.harvard.edu/cgi-bin/np...?bibcode=2004A There are 27 articles that cite the Salaris article. Two those in late 2004 look interesting. I would try the NASA/ADS link and the "Citations to the Article" link. See if anything looks interesting. The following also may be of interest. The following is a plot of 186 OC ages from my personal DSO observing list. http://members.csolutions.net/fisher...ClAgeChart.JPG The galactic year, the time it takes the Sun to complete one revolution around the Milky Way's core, is approx. 220 million years or 8.34 log10(years). Half of all open clusters disperse in just under one galactic year (8.13 log10(years) or 218 million years) - ripped apart by tidal forces. The third quartile of open clusters disperses in just under two galactic years (8.6 log10(years) or about 430 million years). Popular old clusters and moving groups that have survived more than two galactic years and into the fourth quartile include M044 (Beehive Cluster), M048, M067, M073, M093, the Hyades Moving Group, and the Coma Berenices Star Cluster. The youngest clusters in my list are aged around 6.7 log10(years) or approx. 5 million years old. The youngest three are the Tau CMa Cluster a.k.a. the Northern Jewel Box (NGC2362, Caldwell 64); NGC1980 surrounding iot Orion in the Orion stellar nursery region; and, NGC2239, a star cluster associated with the Rosetta Nebula stellar nursery in Mon. Most of the OC ages were assigned to OC's in my master DSO observing list are from tables in Allen's Astrophysical Quantities (2000). - Canopus56 |
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On Feb 27, 5:25 pm, "canopus56" wrote:
Looking at Salaris's paper in NASA/ADS: http://adsabs.harvard.edu/cgi-bin/np...?bibcode=2004A S/b - http://adsabs.harvard.edu/cgi-bin/np...6A...414..163S - C |
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