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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

290 results found.

  1. Swift GRB191226.02: Global MASTER-Net observations report
  2. GRB 191123A: Swift-XRT refined Analysis
  3. GRB 191123A: Swift/UVOT detection
  4. GRB 191101A: Swift/UVOT Upper Limits
  5. GRB 191031A: COATLI Optical Observations
  6. Swift GRB191011.19: Global MASTER-Net observations report
  7. Baksan Neutrino Observatory Alert 190928.37: Global MASTER-Net observations report
  8. Integral GRB190919.99: Global MASTER-Net observations report
  9. LIGO/Virgo S190814bv: MASTER prediscovery and postdiscovery observations DECam candidate DG19wxnjc/AT2019npv field
  10. Baksan Neutrino Observatory Alert 190817.35 Global MASTER-Net observations report
  11. LIGO/Virgo S190814bv Global MASTER-Net observations report
  12. FRB 190806: MASTER optical observation
  13. Fermi trigger No 586896678 Global MASTER-Net observations report
  14. GRB 190731A: no OT detected by MASTER
  15. IceCube Alert 190712.05 Global MASTER-Net observations report
  16. Fermi trigger No 584465880 Global MASTER-Net observations report
  17. Fermi trigger No 584404689 Global MASTER-Net observations report
  18. MAXI GRB190708.83 Global MASTER-Net observations report
  19. LIGO/Virgo S190701ah: Coverage and upper limits from MAXI/GSC observations
  20. Fermi trigger No 583111521 Global MASTER-Net observations report
  21. Swift GRB190624.86 Global MASTER-Net observations report
  22. Swift GRB190613.17 Global MASTER-Net observations report
  23. Fermi trigger No 581841498 Global MASTER-Net observations report
  24. Fermi Fermi trigger No 581002688 Global MASTER-Net observations report
  25. Fermi GRB190525.67 Global MASTER-Net observations report
  26. LIGO/Virgo S190521r Global MASTER-Net observations report
  27. LIGO/Virgo S190519bj Global MASTER-Net observations report
  28. Fermi GRB190517.81 Global MASTER-Net observations report
  29. LIGO/Virgo S190517h Global MASTER-Net observations report
  30. Fermi GRB190515.43 Global MASTER-Net observations report
  31. LIGO/Virgo S190513bm Global MASTER-Net observations report
  32. LIGO/Virgo S190512at Global MASTER-Net observations report
  33. Fermi GRB190510.12 Global MASTER-Net observations report
  34. LIGO/Virgo S190503bf Global MASTER-Net observations report
  35. LIGO/Virgo S190426c: RATIR Optical and NIR Observations of Galaxies
  36. LIGO/Virgo S190425z: RATIR Observations of Galaxies
  37. SWIFT GRB190324.95 Global MASTER-Net observations report
  38. SWIFT GRB190320.05 Global MASTER-Net observations report
  39. GRB190311A: MITSuME Akeno optical observation
  40. GRB190311A: MASTER Global Robotic Net OT optical observation
  41. Swift Trigger 887541: MASTER inspect
  42. GRB190123A: MITSuME Akeno optical upper limits
  43. GRB 190117A: AGILE/MCAL detection of a burst
  44. GRB 190114C: LSGT optical observation
  45. GRB 190114A: Swift/UVOT Observations
  46. Short-duration GRB 181121.4: MASTER-Tavrida possible OT detection near the PGC galaxy during large Fermi error box inspection
  47. GRB 181110A: Swift/UVOT Detection
  48. GRB 181003A: MASTER optical observation
  49. GRB 180925A: Swift/UVOT Detection
  50. GRB 180728A: MASTER early polarization and 19 days monitoring
  51. GRB 180720B: MITSuME Akeno optical observations
  52. IceCube-171106A: MASTER optical observation
  53. GRB 180705A: MASTER optical observation
  54. GRB 180624A: Swift-BAT refined analysis
  55. GRB 180620A iTelescope observation
  56. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  57. GRB 180205A: Swift/UVOT Detection
  58. Swift Trigger on AXP CXOU J164710.2-455216/PSR J1647-4552
  59. GRB 171205A: Host galaxy photometric properties
  60. GRB 171027A: MASTER-OAFA (Argentina) early prompt optical observations
  61. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  62. Trigger 780207: Swift triggers again on AXP CXOU J164710.2-455216/PSR J1647-4552
  63. Swift Trigger on AXP CXOU J164710.2-455216/PSR J1647-4552
  64. GRB 171007A: Swift/UVOT Upper Limits
  65. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  66. AXP CXOU J164710.2-455216: Fermi GBM observation
  67. Swift Trigger AXP CXOU J164710.2-455216: MASTER-OAFA observations
  68. Swift Trigger on AXP CXOU J164710.2-455216
  69. Short GRB 170428A: MASTER-OAFA final reduction of the optical observations
  70. GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
  71. LIGO/Virgo G270580: Las Cumbres Observatory Follow-up Observations
  72. GRB 170127B: MASTER-Kislovodsk early optical observations
  73. GRB 161017A: Lomonosov Gamma Ray and MASTER Optical prompt observations
  74. Trigger 706396: Swift detection of a short burst from PSR 1119-6127
  75. GRB 160726A: Fermi GBM observation
  76. GRB 160714A: MASTER early optical observations
  77. GRB 160227A: Swift/UVOT Detection
  78. GRB 160227A: MASTER prompt OT Detection and LC
  79. GRB 160131A Swift/UVOT Detection
  80. GRB 151210A: GROND Afterglow Confirmation
  81. GRB 150818A: MITSuME Akeno optical upper limits
  82. GRB 150301A: Fermi GBM observation
  83. GRB 150212A: MASTER optical observations
  84. GRB 141026A: Gemini-North optical and NIR imaging
  85. Swift observations of HD 305560
  86. GRB 140930A/MAXI J2259+524: MASTER optical observations
  87. GRB 140907A: MASTER optical observations
  88. GRB 140614B: Swift/UVOT Upper Limits
  89. GRB 140610A: MASTER optical observations
  90. GRB 140423A: TShAO optical observations
  91. GRB 140508A: SAO RAS and MASTER photometric and spectroscopic observations
  92. GRB 140129B: MASTER OT early light curve
  93. GRB 140103A: MASTER-Net early OT detection
  94. IPN Triangulation of SGR-like burst 130913 - probable association with SGR/AXP 1E1841-045
  95. GRB 130725B: Swift/UVOT Observations
  96. Fermi/GBM observation of the Soft Gamma Repeater SGR J1550-5418
  97. Trigger 558399: Swift detection of the Soft Gamma Repeater AXP 1E1547.0-5408
  98. GRB 130511A: SSO 2.3m observation
  99. GRB 130427A: Spectroscopic detection of the SN from the 10.4m GTC
  100. GRB 130427A: photo-z of possible SDSS host galaxy

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