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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"

26507 results found.

  1. GRB110102A: Swift/UVOT observations
  2. GRB110102A: MITSuME Okayama Optical Observation
  3. GRB 110102A: Fermi GBM observation
  4. GRB 110102A: Enhanced Swift-XRT position
  5. GRB 110102A: Swift detection of a burst with an optical detection
  6. GRB 101225A: P60 Observations
  7. GRB 101225A: MAXI/GSC observations
  8. GRB 101225A Late-time emission observed by Swift-BAT
  9. Tentative redshift of GRB101225A (Christmas's burst) from Swift-XRT data
  10. GRB 101225A, Swift-BAT refined analysis
  11. GRB 101225A: Swift/UVOT Detection
  12. GRB 101225A: Swift-XRT refined Analysis
  13. GRB 101225A: Enhanced Swift-XRT position
  14. Trigger 441015 / GRB 101225A: Further NOT optical observation
  15. Trigger 441015 / GRB 101225A: NOT optical afterglow candidate
  16. GRB 101225A (Swift trigger 441015): optical upper limit
  17. Trigger 441015: Swift detection of a possible burst or transient
  18. GRB 101224A: NOT optical observation
  19. GRB 101224A: Pre-event imaging from DeepSky; Detection of a source in the XRT error circle
  20. GRB 101224A: Swift/UVOT Upper Limits
  21. GRB 101224A: Fermi GBM observation
  22. GRB 101224A: Swift-XRT refined Analysis
  23. GRB101224A: MITSuME Okayama optical upper limits
  24. GRB 101224A - UVOT-enhanced XRT position
  25. GRB 101224A: Swift detection of a short burst
  26. GRB 101219A: Chandra Observations
  27. GRB 101219B: Swift/UVOT refined analysis
  28. GRB 101219B: Swift-XRT refined Analysis
  29. GRB 101219B: Enhanced Swift-XRT position
  30. GRB 101219A: MITSuME Ishigakijima Optical upper limits
  31. GRB 101219B: GROND Detection of the Optical/NIR Afterglow
  32. GRB 101219B: Fermi GBM observation
  33. GRB 101219A: IAC80 optical observations
  34. GRB 101219A: Swift-XRT refined Analysis
  35. GRB 101219B: Swift detection of a burst with an optical afterglow
  36. GRB 101219A: Swift/UVOT Upper Limits
  37. GRB 101219A: GROND Upper limits
  38. GRB 101219A: Magellan NIR observations
  39. GRB 101219A: Further Gemini-South Imaging
  40. GRB 101219A: Swift-BAT refined analysis
  41. GRB 101219A - NOT observation - upper limit
  42. GRB 101219A: SARA-N Upper Limit
  43. GRB 101219A: REM optical and NIR observations
  44. GRB 101219A: Swift detection of a short hard burst
  45. GRB 101213A : Suzaku WAM observation of the prompt emission
  46. Redshift solution(s) for GRB101213A from Swift-XRT data
  47. Konus-Wind observation of GRB 101213A
  48. XRF 101117A, RIMOTS optical upper limits
  49. GRB 101213A: Fermi GBM observation
  50. GRB 101213A: Swift-XRT refined Analysis
  51. GRB 101213A: Swift/UVOT Upper Limits
  52. GRB 101213A: Enhanced Swift-XRT position
  53. GRB 101213: object within the X-ray error circle
  54. GRB 101213A: Swift detection of a burst
  55. GRB101204A: Swift/UVOT observations
  56. GRB 101204A: Swift-XRT refined Analysis
  57. GRB101204A GROND Detection of the Optical/NIR Afterglow
  58. GRB 101204A Afterglow Candidate, VATT Observations
  59. GRB 101129A : Suzaku WAM observation of the prompt emission
  60. GRB 101204A Swift-XRT/UVOT afterglow candidate
  61. GRB 101204A detected in ground analysis of BAT data
  62. GRB 101129A SHB found by IPN and in ground analysis of BAT data
  63. GRB 101201A: Fermi GBM observation
  64. GRB 101201A: Swift-XRT refined Analysis
  65. GRB 101201A: Swift/UVOT Detection
  66. GRB 101201A: GROND Detection of the Optical/NIR Afterglow
  67. GRB 101201A detected in ground analysis of BAT data
  68. GRB 101123A: ROTSE optical observations
  69. GRB 101123A: MASTER prompt optical observations
  70. GRB 101123A: Fermi GBM detection
  71. Optical observation of GRB 101024A
  72. GRB 101117B: GROND Upper limits
  73. GRB 101117B: Swift/UVOT Observations of the Optical Afterglow
  74. GRB 101112A: OSN and BTA observations
  75. XRF 101117A: Palomar Transient Factory Observations
  76. GRB 101117B: Swift-XRT refined analysis
  77. GRB101114A: Swift/UVOT Upper Limits
  78. GRB 101117B: Swift-BAT refined analysis
  79. GRB 101117B: Enhanced Swift-XRT position
  80. GRB 101117B: Swift detection of a burst
  81. GRB 101114A: GROND Upper limits
  82. Konus-Wind observation of GRB 101114A
  83. Fermi GBM detection of a burst from a galactic source
  84. GRB 101114A: Swift-XRT candidate afterglow detection and analysis
  85. GRB 101114A, Swift-BAT GRB detected by ground processing
  86. GRB 101112A: Fermi GBM detection
  87. GRB 101112A: optical observations
  88. GRB 101112A - XRT source detection/analysis
  89. GRB 101112A: BOOTES-2/TELMA optical afterglow candidate
  90. GRB101112A: Liverpool Telescope Afterglow Candidate
  91. GRB 101030A : MOA optical observation
  92. GRB 101030A: GROND optical/NIR afterglow candidate
  93. GRB 101030A : Swift XRT refined analysis
  94. GRB 101030A: Swift/UVOT Upper Limits
  95. GRB 101030A: Swift-BAT refined analysis
  96. GRB 101030A: Enhanced Swift-XRT position
  97. GRB 101030A: Swift detection of a burst
  98. GRB 090111, the review of the sky area in plate archives (1976-1996)
  99. Konus-Wind observation of GRB 101023A
  100. GRB 101024A: GROND optical/NIR observations

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