Color Gradient in the King Type Globular Cluster NGC 7089
We use BV CCD images to investigate the reality of the color gradient within a King type globular cluster NGC 7089. Surface photometry shows that there is a strong radial color gradient in the central region of the cluster in the sense of bluer center with the amplitude of -0.39 +/- 0.07 mag/arcsec2...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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The Korean Space Science Society
1999-12-01
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| Series: | Journal of Astronomy and Space Sciences |
| Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/1999/v16n2/OJOOBS_1999_v16n2_91.pdf |
| _version_ | 1797370496068616192 |
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| author | Young-Jong Sohn Mun-Suk Chun Jae-Woo Lee Jungmin Oh |
| author_facet | Young-Jong Sohn Mun-Suk Chun Jae-Woo Lee Jungmin Oh |
| author_sort | Young-Jong Sohn |
| collection | DOAJ |
| description | We use BV CCD images to investigate the reality of the color gradient within a King type globular cluster NGC 7089. Surface photometry shows that there is a strong radial color gradient in the central region of the cluster in the sense of bluer center with the amplitude of -0.39 +/- 0.07 mag/arcsec2 in (B - V). In the outer region of the cluster, however, the radial color gradient shows a reverse case, i.e., redder toward the center. (B - V) color profile which was derived from resolved stars in VGC 7089 field also shows a significant color gradient in the central region of the clusters, indicating that lights from the combination of red giant stars and blue horizontal branch stars cause the radial color gradient. Color gradient of the outer region of NGC 7089 may be due to the unresolved background of the cluster. Similar color gradients in the central area of clusters have been previously observed exserved exclusively in highly concentrated systems classified as post core collapse clusters. We caution, however, to confirm the reality of the color gradient from resolved stars, we need more accurate imaging data of the cluster with exceptional seeing condition because the effect of completeness correlates with local density of stars. |
| first_indexed | 2024-03-08T18:02:27Z |
| format | Article |
| id | doaj.art-6871257259334b7e9aa68f98d2705245 |
| institution | Directory Open Access Journal |
| issn | 2093-5587 2093-1409 |
| language | English |
| last_indexed | 2024-03-08T18:02:27Z |
| publishDate | 1999-12-01 |
| publisher | The Korean Space Science Society |
| record_format | Article |
| series | Journal of Astronomy and Space Sciences |
| spelling | doaj.art-6871257259334b7e9aa68f98d27052452024-01-02T00:03:44ZengThe Korean Space Science SocietyJournal of Astronomy and Space Sciences2093-55872093-14091999-12-0116291104Color Gradient in the King Type Globular Cluster NGC 7089Young-Jong Sohn0Mun-Suk Chun1Jae-Woo Lee2Jungmin Oh3Center for Space Astrophysics, Yonsei University, Seoul 120-749, KoreaDepartment of Astronomy, Yonsei University, Seoul 120-749, KoreaDepartment of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599-3255, USADepartment of Astronomy, Yonsei University, Seoul 120-749, KoreaWe use BV CCD images to investigate the reality of the color gradient within a King type globular cluster NGC 7089. Surface photometry shows that there is a strong radial color gradient in the central region of the cluster in the sense of bluer center with the amplitude of -0.39 +/- 0.07 mag/arcsec2 in (B - V). In the outer region of the cluster, however, the radial color gradient shows a reverse case, i.e., redder toward the center. (B - V) color profile which was derived from resolved stars in VGC 7089 field also shows a significant color gradient in the central region of the clusters, indicating that lights from the combination of red giant stars and blue horizontal branch stars cause the radial color gradient. Color gradient of the outer region of NGC 7089 may be due to the unresolved background of the cluster. Similar color gradients in the central area of clusters have been previously observed exserved exclusively in highly concentrated systems classified as post core collapse clusters. We caution, however, to confirm the reality of the color gradient from resolved stars, we need more accurate imaging data of the cluster with exceptional seeing condition because the effect of completeness correlates with local density of stars.http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/1999/v16n2/OJOOBS_1999_v16n2_91.pdf |
| spellingShingle | Young-Jong Sohn Mun-Suk Chun Jae-Woo Lee Jungmin Oh Color Gradient in the King Type Globular Cluster NGC 7089 Journal of Astronomy and Space Sciences |
| title | Color Gradient in the King Type Globular Cluster NGC 7089 |
| title_full | Color Gradient in the King Type Globular Cluster NGC 7089 |
| title_fullStr | Color Gradient in the King Type Globular Cluster NGC 7089 |
| title_full_unstemmed | Color Gradient in the King Type Globular Cluster NGC 7089 |
| title_short | Color Gradient in the King Type Globular Cluster NGC 7089 |
| title_sort | color gradient in the king type globular cluster ngc 7089 |
| url | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/1999/v16n2/OJOOBS_1999_v16n2_91.pdf |
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