NGC 637 - Misplaced Pages

Open star cluster in the constellation Cassiopeia

NGC 637

Observation data (J2000.0 epoch)
Right ascension	01 43 04.0
Declination	+64° 02′ 24″
Distance	7.045 ± 1.409 kly (2.160 ± 0.432 kpc)
Apparent magnitude (V)	8.2
Apparent dimensions (V)	4.2′
Physical characteristics
Estimated age	10 ± 5 Myr
Other designations	Cr 17, NGC 637
Associations
Constellation	Cassiopeia
See also: Open cluster, List of open clusters

NGC 637 is an open cluster of stars in the northern constellation of Cassiopeia, positioned about 1.5° to the WNW of the star Epsilon Cassiopeiae. The cluster was discovered on 9 November 1787 by German-born English astronomer William Herschel. It is located in the Perseus Arm of the Milky Way, at a distance of approximately 7,045 light years from the Sun. The cluster is small but compact, and is readily visible in a small telescope.

This is a young cluster with an estimated age of 5–15 million years. It has a Trumpler class of I2m, indicating it is strongly concentrated (I) with an intermediate range of brightness variation (2) and a moderate richness of stars (m). The cluster has 55 members and an angular radius of 4′.2, corresponding to a physical radius of 9.8 ly (3.0 pc). It has a core radius of 0.36′±0.13′.

The seven brightest members are all over 10th magnitude, with five known to be variable. A total of four β Cephei-type variables have been identified, one of the highest such totals for an open cluster. A classical Be star candidate has been detected. The distribution of the cluster's stars on the Hertzsprung–Russell diagram shows a noticeable gap on the main sequence, which is not explained by missing data.

References

^ Wu, Zhen-Yu; et al. (November 2009). "The orbits of open clusters in the Galaxy". Monthly Notices of the Royal Astronomical Society. 399 (4): 2146–2164. arXiv:0909.3737. Bibcode:2009MNRAS.399.2146W. doi:10.1111/j.1365-2966.2009.15416.x. S2CID 6066790.
^ O'Meara, Steve (June 14, 2007). Herschel 400 Observing Guide. Cambridge University Press. p. 296. ISBN 9780521858939.
^ Yadav, R. K. S.; Kumar, Brijesh; Subramaniam, A.; Sagar, Ram; et al. (November 2008). "Optical and near-infrared photometric study of the open cluster NGC 637 and 957". Monthly Notices of the Royal Astronomical Society. 390 (3): 985–996. arXiv:0810.1409. Bibcode:2008MNRAS.390..985Y. doi:10.1111/j.1365-2966.2008.13740.x. S2CID 18096918.
"NGC 637". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-02-29.
Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 1. Sky Publishing Corporation and the European Space Agency. p. 34. ISBN 0-933346-84-0.
"New General Catalog Objects: NGC 600 - 649". cseligman.com. Retrieved 2018-01-05.
^ Kharchenko, N. V.; et al. (August 2005). "Astrophysical parameters of Galactic open clusters". Astronomy and Astrophysics. 438 (3): 1163–1173. arXiv:astro-ph/0501674. Bibcode:2005A&A...438.1163K. doi:10.1051/0004-6361:20042523. S2CID 9079873.
^ Hasan, Priya; et al. (November 2008). "The structure and dynamics of young star clusters: King 16, NGC 1931, NGC 637 and NGC 189". Astrophysics and Space Science. 318 (1–2): 25–33. arXiv:0808.1785. Bibcode:2008Ap&SS.318...25H. doi:10.1007/s10509-008-9888-2. S2CID 18982625.
Handler, G.; Meingast, S. (September 2011). "New β Cephei stars in the young open cluster NGC 637". Astronomy & Astrophysics. 533: 6. arXiv:1105.3121. Bibcode:2011A&A...533A..70H. doi:10.1051/0004-6361/201116874. S2CID 55061600. A70.

External links

NGC 637 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
SEDS

v t e New General Catalogue 500 to 999
500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999
Astronomical catalog List of NGC objects 1–1000

New General Catalogue 500 to 999

Constellation of Cassiopeia

Stars

Bayer	α (Schedar) β (Caph) γ (Navi/Tsih) δ (Ruchbah) ε (Segin) ζ (Fulu) η (Achird) θ (Marfak) ι κ λ μ ν ξ ο π ρ σ τ υ υ (Castula) φ χ ψ ω
Flamsteed	1 2 4 6 9 10 12 42 47 48 (A) 49 50 54
Variable	R S TZ WZ YZ (21) AO AR PZ V373 V509 V547 V669 V705 V762 V863 V773 V987 V1022 V1405
HR	5 91 144 196 244 273 297 743 932 8832 8853 8881
HD	861 7924 7977 15558 17156 (Nushagak) 240210 240237 240429 240430
Other	BD+60°2522 Gliese 49 IRAS 23304+6147 LS I +61 303 PSR J0205+6449 Tycho G 4U 0142+61 WR 2 WR 3

Exoplanets	HD 7924 b HD 17156 b HD 219134 b c d e (h) f g HD 240210 b HD 240237 b

Star clusters	Messier 52 Messier 103 NGC 103 NGC 110 NGC 129 NGC 133 NGC 136 NGC 146 NGC 189 NGC 225 NGC 358 NGC 366 NGC 381 NGC 433 NGC 436 NGC 457 NGC 559 NGC 637 NGC 654 NGC 659 NGC 663 NGC 1027 NGC 7789 NGC 7790 Trumpler 3

Nebulae

NGC	281 7635
Other	3C 58 Cassiopeia A Heart Nebula IC 289 IC 1805 KjPn 8 LBN 114.55+00.22 Sh 2-185 Westerhout 5

Galaxies

NGC	147 185 278
Other	Andromeda VII 3C 20 3C 35 Dwingeloo 1 Dwingeloo 2 MB 3 IC 10 Maffei 1 Maffei 2 QSO B0153+744

Astronomical events	SN 1181 SN 1572 (B)