Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal ...Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.展开更多
Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. Accor...Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are:sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.展开更多
The Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center(XSTPS-GAC)is a photometric sky survey that covers nearly 6000 deg^2 towards the Galactic Anti-center(GAC) in the g,r,i bands. Half of its s...The Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center(XSTPS-GAC)is a photometric sky survey that covers nearly 6000 deg^2 towards the Galactic Anti-center(GAC) in the g,r,i bands. Half of its survey field is located on the Galactic Anti-center disk,which makes XSTPSGAC highly suitable to search for new open clusters in the GAC region. In this paper,we report new open cluster candidates discovered in this survey,as well as properties of these open cluster candidates,such as age,distance and reddening,derived by isochrone fitting in the color-magnitude diagram(CMD).These open cluster candidates are stellar density peaks detected in the star density maps by applying the method from Koposov et al. Each candidate is inspected in terms of its true color image composed from three XSTPS-GAC band images. Then its CMD is checked,in order to identify whether the central region stars have a clear isochrone-like trend differing from background stars. The parameters derived from isochrone fitting for these candidates are mainly based on three band photometry of XSTPS-GAC.Moreover,when these new candidates are able to be seen clearly in 2 MASS data,their parameters are also derived based on the 2 MASS(J-H,J) CMD. There are a total of 320 known open clusters rediscovered and 24 new open cluster candidates discovered in this work. Furthermore,the parameters of these new candidates,as well as another 11 previously known open clusters,are properly determined for the first time.展开更多
It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is adva...It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is advanced in this paper. The equivalent diameter of the pore of a fibre web is used to calculate the valid opening size instead of the maximum diameter of inscribed circle used, because the fibres in practical fibre webs are flexible elastomers with definite diameters and the pore of fibre web may produce deformation in screening teat and engineering usage. The results show that the theoretical calculations coincide well with the engineering measurements. This method offers a theoretical basis for computer simulation to the performance of filters of heatbonded nonwoven fabrics.展开更多
Distinguished Guests,Ladies and Gentlemen,Dear friends,On behalf of the Chinese Association for International Understanding(CAFIU),I would like to start by extending my warmest welcome to all representatives from home...Distinguished Guests,Ladies and Gentlemen,Dear friends,On behalf of the Chinese Association for International Understanding(CAFIU),I would like to start by extending my warmest welcome to all representatives from home and abroad,who come to attend the 2013"Understanding展开更多
This paper presents a preliminary test of the k-th nearest neighbor distance (KNND) method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars (〈 100 pc) from the Gaia-DR1 catalog,...This paper presents a preliminary test of the k-th nearest neighbor distance (KNND) method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars (〈 100 pc) from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions (the Hyades and Coma Berenices (Coma Ber) open clusters), and obtain 57 reliable cluster members. Based on these cluster members, the distances to the Hyades and Coma Ber clusters are determined to be 46.0±0.2 and 83.5±0.3 pc, respectively. Our results demonstrate that the KNND method can be used to detect open clusters based on a large volume of astrometry data.展开更多
I’d like to take this opportunity,, on behalf of China National Space Administration and the host organization, the Chinese Society of Astronautics, to extend our best wishes to the opening of the Conference and warm...I’d like to take this opportunity,, on behalf of China National Space Administration and the host organization, the Chinese Society of Astronautics, to extend our best wishes to the opening of the Conference and warmly welcome all delegates here both from home and abroad. The Young Astronauts International is an international organization which devotes itself to the space popular science education among young people.展开更多
This session of the Forum has the theme, “The Chinese Dream: New Progress in the Cause of Human Rights in China.” This theme concentrates on such important subtopics as “The Chinese Dream and Human Rights” ,
In November 2012, immediately after the close of the 18th National Congress of the Communist Party of China (CPC), CPC Central Committee General Secretary Xi Jinping proposed to "realize the Chinese dream of the gr...In November 2012, immediately after the close of the 18th National Congress of the Communist Party of China (CPC), CPC Central Committee General Secretary Xi Jinping proposed to "realize the Chinese dream of the great revival of the Chinese nation." He emphasized that the fulfillment of the Chinese dream regarding the great revival of the Chinese nation is simply the realization of the country's prosperity, the nation's revival and the people's happiness. All in all, the Chinese dream is the people's dream.展开更多
Since its initiation in 2008, the Beijing Forum on Human Rights has been bent on promoting our mutual understanding and expanding our common grounds. It has carried out very fruitful exchanges and researches around ma...Since its initiation in 2008, the Beijing Forum on Human Rights has been bent on promoting our mutual understanding and expanding our common grounds. It has carried out very fruitful exchanges and researches around many important questions concerning human rights development, and hence attained great achievements. It has played avery constructive role in promoting exchanges about and cooperation in human rights between China and other countries, becoming an important and influential platform for international dialogs over human rights.展开更多
The hepatitis E virus(HEV),a member of the Hepeviridae family,is a small,non-enveloped icosahedral virus divided into eight distinct genotypes(HEV-1 to HEV-8).Only genotypes 1 to 4 are known to cause diseases in human...The hepatitis E virus(HEV),a member of the Hepeviridae family,is a small,non-enveloped icosahedral virus divided into eight distinct genotypes(HEV-1 to HEV-8).Only genotypes 1 to 4 are known to cause diseases in humans.Genotypes 1 and 2 commonly spread via fecal-oral transmission,often through the consum-ption of contaminated water.Genotypes 3 and 4 are known to infect pigs,deer,and wild boars,often transferring to humans through inadequately cooked meat.Acute hepatitis caused by HEV in healthy individuals is mostly asymptomatic or associated with minor symptoms,such as jaundice.However,in immunosup-pressed individuals,the disease can progress to chronic hepatitis and even escalate to cirrhosis.For pregnant women,an HEV infection can cause fulminant liver failure,with a potential mortality rate of 25%.Mortality rates also rise amongst cirrhotic patients when they contract an acute HEV infection,which can even trigger acute-on-chronic liver failure if layered onto pre-existing chronic liver disease.As the prevalence of HEV infection continues to rise worldwide,highlighting the particular risks associated with severe HEV infection is of major medical interest.This text offers a brief summary of the characteristics of hepatitis developed by patient groups at an elevated risk of severe HEV infection.展开更多
We compile a new sample of 89 open clusters with ages, distances and metallicities available. We derive a radial iron gradient of about -0.099±0.008 dex kpc^(-1) (unweighted) for the whole sample, which is somewh...We compile a new sample of 89 open clusters with ages, distances and metallicities available. We derive a radial iron gradient of about -0.099±0.008 dex kpc^(-1) (unweighted) for the whole sample, which is somewhat greater than the most recent determination of oxygen gradient from nebulae and young stars. By dividing the clusters into age groups, we show that the iron gradient was steeper in the past and has evolved slowly in time. Current data show a substantial scatter of the cluster metallicities indicating that the Galactic disk has undergone a very rapid, inhomogeneous enrichment. Also, based on a simple, but quite successful model of chemical evolution of the Milky Way disk, we make a detailed calculation of the iron abundance gradient and its time evolution. The predicted current iron gradient is about -0.072 dex kpc^(-1). The model also predicts a steady flattening of the iron gradient with time, which agrees with the result from our open cluster sample.展开更多
The international conference on Kampuchea declded on August 1 in Paris to send a UN fact-finding mission to the country to arrange a peace settlement. The Fatah Movement, the mainstream group in the Palestine Liberati...The international conference on Kampuchea declded on August 1 in Paris to send a UN fact-finding mission to the country to arrange a peace settlement. The Fatah Movement, the mainstream group in the Palestine Liberation Organization (PLO), opened its fifth general congress on August 3 in Tunis. PLO Chairman and President of the State of Palestine Yasser Arafat and Tunisian President Zine E1 Abidine Ben All addressed the opening ceremony.展开更多
From photometric observations and star counts, the existence of a bar in the central few kpc of the Galaxy is suggested. It is generally thought that our Galaxy is surrounded by a massive invisible halo. The gravitati...From photometric observations and star counts, the existence of a bar in the central few kpc of the Galaxy is suggested. It is generally thought that our Galaxy is surrounded by a massive invisible halo. The gravitational potential of the Galaxy is therefore made nonaxisymmetric generated by the central triaxial bar, by the outer triaxial halo, and/or by the spiral structures. Selecting nearly 300 open clusters with complete spatial velocity measurements and ages, we were able to construct the rotation curve of the Milky Way within a range of 3 kpc of the Sun. Using a dynamic model for an assumed elliptical disk, a clear weak elliptical potential of the disk with ellipticity of ε(R0) = 0.060 4± 0.012 is detected, the Sun is found to be near the minor axis, displaced by 30°±3°. The motion of the clusters is suggested to be on an oval orbit rather than on a circular one.展开更多
The U.S. Senate unanimously confirmed, by a.92 to 0 vote, Representative Dick Cheney as defence secretary on March 17. On March 18, the US space shuttle "Discovery" landed in California, completing a flight ...The U.S. Senate unanimously confirmed, by a.92 to 0 vote, Representative Dick Cheney as defence secretary on March 17. On March 18, the US space shuttle "Discovery" landed in California, completing a flight of nearly five days that covered about three million kilometres. The Second Session of the Seventh National People’s Congress opened on March 20 in Beijing. Chinese Premier Li展开更多
Galactic open clusters (OCs) that survive the early gas-expulsion phase are gradually de- stroyed over time by the action of disruptive dynamical processes. Their final evolutionary stages are characterized by a poo...Galactic open clusters (OCs) that survive the early gas-expulsion phase are gradually de- stroyed over time by the action of disruptive dynamical processes. Their final evolutionary stages are characterized by a poorly populated concentration of stars called an open cluster remnant (OCR). This study is devoted to assessing the real physical nature of the OCR candidate NGC 7193. GMOS/Gemini spectroscopy of 53 stars in the inner target region were obtained to derive radial velocities and at- mospheric parameters. We also employed photometric and proper motion data. The analysis method consists of the following steps: (i) analysis of the statistical resemblance between the cluster and a set of field samples with respect to the sequences defined in color-magnitude diagrams (CMDs); (ii) a 5-dimensional iterative exclusion routine was employed to identify outliers from kinematical and posi- tional data; (iii) isochrone fitting to thes× (J - Ks) CMD of the remaining stars and the dispersion of spectral types along empirical sequences in the (J - H) × (H - Ks) diagram were checked. A group of stars was identified for which the mean heliocentric distance is compatible with that obtained via isochrone fitting and whose metallicities are compatible with each other. Fifteen of the member stars observed spectroscopically were identified together with another 19 probable members. Our results indi- cate that NGC 7193 is a genuine OCR, of a once very populous OC, for which the following parameters were derived: d = 501±46 pc, t = 2.5±1.2 Gyr, ([Fe/H]) = -0.17±0.23 and E(B-V) = 0.05±0.05. Its luminosity and mass functions show depletion of low mass stars, confirming the OCR is in a dynam- ically evolved state.展开更多
基金the National Natural Science Foundation of China(NSFC)through grants 12003022,12373035,12233009 and 12173047support from the Youth Innovation Promotion Association of the CAS(grant No.2022055)。
文摘Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.
文摘Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are:sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.
基金supported by the National Natural Science Foundation of China (NSFC,Grant Nos.11473001,11233004,11078006,11633009 and 11273067)the Minor Planet Foundation of Purple Mountain Observatory+2 种基金supported by the National Key Basic Research Program of China (2014CB845700)the China Postdoctoral Science Foundation (Grant No.2017M610695)supported by Special Funding for Advanced Users,budgeted and administrated by the Center for Astronomical Mega-Science,Chinese Academy of Sciences
文摘The Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center(XSTPS-GAC)is a photometric sky survey that covers nearly 6000 deg^2 towards the Galactic Anti-center(GAC) in the g,r,i bands. Half of its survey field is located on the Galactic Anti-center disk,which makes XSTPSGAC highly suitable to search for new open clusters in the GAC region. In this paper,we report new open cluster candidates discovered in this survey,as well as properties of these open cluster candidates,such as age,distance and reddening,derived by isochrone fitting in the color-magnitude diagram(CMD).These open cluster candidates are stellar density peaks detected in the star density maps by applying the method from Koposov et al. Each candidate is inspected in terms of its true color image composed from three XSTPS-GAC band images. Then its CMD is checked,in order to identify whether the central region stars have a clear isochrone-like trend differing from background stars. The parameters derived from isochrone fitting for these candidates are mainly based on three band photometry of XSTPS-GAC.Moreover,when these new candidates are able to be seen clearly in 2 MASS data,their parameters are also derived based on the 2 MASS(J-H,J) CMD. There are a total of 320 known open clusters rediscovered and 24 new open cluster candidates discovered in this work. Furthermore,the parameters of these new candidates,as well as another 11 previously known open clusters,are properly determined for the first time.
文摘It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is advanced in this paper. The equivalent diameter of the pore of a fibre web is used to calculate the valid opening size instead of the maximum diameter of inscribed circle used, because the fibres in practical fibre webs are flexible elastomers with definite diameters and the pore of fibre web may produce deformation in screening teat and engineering usage. The results show that the theoretical calculations coincide well with the engineering measurements. This method offers a theoretical basis for computer simulation to the performance of filters of heatbonded nonwoven fabrics.
文摘Distinguished Guests,Ladies and Gentlemen,Dear friends,On behalf of the Chinese Association for International Understanding(CAFIU),I would like to start by extending my warmest welcome to all representatives from home and abroad,who come to attend the 2013"Understanding
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.11403004)
文摘This paper presents a preliminary test of the k-th nearest neighbor distance (KNND) method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars (〈 100 pc) from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions (the Hyades and Coma Berenices (Coma Ber) open clusters), and obtain 57 reliable cluster members. Based on these cluster members, the distances to the Hyades and Coma Ber clusters are determined to be 46.0±0.2 and 83.5±0.3 pc, respectively. Our results demonstrate that the KNND method can be used to detect open clusters based on a large volume of astrometry data.
文摘I’d like to take this opportunity,, on behalf of China National Space Administration and the host organization, the Chinese Society of Astronautics, to extend our best wishes to the opening of the Conference and warmly welcome all delegates here both from home and abroad. The Young Astronauts International is an international organization which devotes itself to the space popular science education among young people.
文摘This session of the Forum has the theme, “The Chinese Dream: New Progress in the Cause of Human Rights in China.” This theme concentrates on such important subtopics as “The Chinese Dream and Human Rights” ,
文摘In November 2012, immediately after the close of the 18th National Congress of the Communist Party of China (CPC), CPC Central Committee General Secretary Xi Jinping proposed to "realize the Chinese dream of the great revival of the Chinese nation." He emphasized that the fulfillment of the Chinese dream regarding the great revival of the Chinese nation is simply the realization of the country's prosperity, the nation's revival and the people's happiness. All in all, the Chinese dream is the people's dream.
文摘Since its initiation in 2008, the Beijing Forum on Human Rights has been bent on promoting our mutual understanding and expanding our common grounds. It has carried out very fruitful exchanges and researches around many important questions concerning human rights development, and hence attained great achievements. It has played avery constructive role in promoting exchanges about and cooperation in human rights between China and other countries, becoming an important and influential platform for international dialogs over human rights.
基金Supported by Interreg V-A Romania-Hungary Programme,No.ROHU339.
文摘The hepatitis E virus(HEV),a member of the Hepeviridae family,is a small,non-enveloped icosahedral virus divided into eight distinct genotypes(HEV-1 to HEV-8).Only genotypes 1 to 4 are known to cause diseases in humans.Genotypes 1 and 2 commonly spread via fecal-oral transmission,often through the consum-ption of contaminated water.Genotypes 3 and 4 are known to infect pigs,deer,and wild boars,often transferring to humans through inadequately cooked meat.Acute hepatitis caused by HEV in healthy individuals is mostly asymptomatic or associated with minor symptoms,such as jaundice.However,in immunosup-pressed individuals,the disease can progress to chronic hepatitis and even escalate to cirrhosis.For pregnant women,an HEV infection can cause fulminant liver failure,with a potential mortality rate of 25%.Mortality rates also rise amongst cirrhotic patients when they contract an acute HEV infection,which can even trigger acute-on-chronic liver failure if layered onto pre-existing chronic liver disease.As the prevalence of HEV infection continues to rise worldwide,highlighting the particular risks associated with severe HEV infection is of major medical interest.This text offers a brief summary of the characteristics of hepatitis developed by patient groups at an elevated risk of severe HEV infection.
基金the National Natural Science Foundation ofChina (No. 19873014) and NKBRSFG19990754, and partly by SRF for ROCS, SEM.
文摘We compile a new sample of 89 open clusters with ages, distances and metallicities available. We derive a radial iron gradient of about -0.099±0.008 dex kpc^(-1) (unweighted) for the whole sample, which is somewhat greater than the most recent determination of oxygen gradient from nebulae and young stars. By dividing the clusters into age groups, we show that the iron gradient was steeper in the past and has evolved slowly in time. Current data show a substantial scatter of the cluster metallicities indicating that the Galactic disk has undergone a very rapid, inhomogeneous enrichment. Also, based on a simple, but quite successful model of chemical evolution of the Milky Way disk, we make a detailed calculation of the iron abundance gradient and its time evolution. The predicted current iron gradient is about -0.072 dex kpc^(-1). The model also predicts a steady flattening of the iron gradient with time, which agrees with the result from our open cluster sample.
文摘The international conference on Kampuchea declded on August 1 in Paris to send a UN fact-finding mission to the country to arrange a peace settlement. The Fatah Movement, the mainstream group in the Palestine Liberation Organization (PLO), opened its fifth general congress on August 3 in Tunis. PLO Chairman and President of the State of Palestine Yasser Arafat and Tunisian President Zine E1 Abidine Ben All addressed the opening ceremony.
基金Supported by the National Natural Science Foundation of China.
文摘From photometric observations and star counts, the existence of a bar in the central few kpc of the Galaxy is suggested. It is generally thought that our Galaxy is surrounded by a massive invisible halo. The gravitational potential of the Galaxy is therefore made nonaxisymmetric generated by the central triaxial bar, by the outer triaxial halo, and/or by the spiral structures. Selecting nearly 300 open clusters with complete spatial velocity measurements and ages, we were able to construct the rotation curve of the Milky Way within a range of 3 kpc of the Sun. Using a dynamic model for an assumed elliptical disk, a clear weak elliptical potential of the disk with ellipticity of ε(R0) = 0.060 4± 0.012 is detected, the Sun is found to be near the minor axis, displaced by 30°±3°. The motion of the clusters is suggested to be on an oval orbit rather than on a circular one.
文摘The U.S. Senate unanimously confirmed, by a.92 to 0 vote, Representative Dick Cheney as defence secretary on March 17. On March 18, the US space shuttle "Discovery" landed in California, completing a flight of nearly five days that covered about three million kilometres. The Second Session of the Seventh National People’s Congress opened on March 20 in Beijing. Chinese Premier Li
基金the Brazilian financial agencies FAPEMIG (grant APQ01858-12)CNPq+2 种基金the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technologyfunded by the National Aeronautics and Space Administrationthe National Science Foundation
文摘Galactic open clusters (OCs) that survive the early gas-expulsion phase are gradually de- stroyed over time by the action of disruptive dynamical processes. Their final evolutionary stages are characterized by a poorly populated concentration of stars called an open cluster remnant (OCR). This study is devoted to assessing the real physical nature of the OCR candidate NGC 7193. GMOS/Gemini spectroscopy of 53 stars in the inner target region were obtained to derive radial velocities and at- mospheric parameters. We also employed photometric and proper motion data. The analysis method consists of the following steps: (i) analysis of the statistical resemblance between the cluster and a set of field samples with respect to the sequences defined in color-magnitude diagrams (CMDs); (ii) a 5-dimensional iterative exclusion routine was employed to identify outliers from kinematical and posi- tional data; (iii) isochrone fitting to thes× (J - Ks) CMD of the remaining stars and the dispersion of spectral types along empirical sequences in the (J - H) × (H - Ks) diagram were checked. A group of stars was identified for which the mean heliocentric distance is compatible with that obtained via isochrone fitting and whose metallicities are compatible with each other. Fifteen of the member stars observed spectroscopically were identified together with another 19 probable members. Our results indi- cate that NGC 7193 is a genuine OCR, of a once very populous OC, for which the following parameters were derived: d = 501±46 pc, t = 2.5±1.2 Gyr, ([Fe/H]) = -0.17±0.23 and E(B-V) = 0.05±0.05. Its luminosity and mass functions show depletion of low mass stars, confirming the OCR is in a dynam- ically evolved state.