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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"

32494 results found.

  1. GRB 070411: TAROT Calern observatory optical observations
  2. GRB 070419A, deep LBT photometry and possible supernova detection
  3. GRB070520B: optical observations
  4. GRB070520: optical observation
  5. GRB070518: optical observation
  6. GRB070521: optical observation
  7. Swift/UVOT refined analysis of GRB070531
  8. GRB 070531: Swift-BAT refined analysis
  9. GRB 070531: Swift-XRT position
  10. GRB 070531: Liverpool Telescope Optical Observations
  11. GRB 070529: SARA upper limit
  12. Swift/UVOT refined analysis of GRB070529
  13. GRB 070529: MARGE Observations
  14. GRB 070529: Optical aterglow from MIRO
  15. GRB 070529: Gemini Redshift
  16. GRB 070529: Swift-XRT refined analysis
  17. GRB 070529, Swift-BAT refined analysis
  18. GRB 070529: Xinglong TNT Optical Upper Limit
  19. GRB 070412: Deep Keck imaging
  20. Swift Triggers 280447, 280450 and 280451 are invalid
  21. GRB 070518, deep LBT photometry
  22. GRB 070518: MARGE Observations
  23. Konus-Wind observation of GRB 070521
  24. GRB 070518: optical observation
  25. GRB070521: Second Epoch Gemini Imaging
  26. GRB070521: NIR observations
  27. GRB070520B: NIR observations
  28. GRB 070521: Swift/UVOT Upper Limits
  29. GRB 070521, optical observation
  30. GRB 070521: Swift-XRT refined analysis
  31. GRB 070521: Keck imaging
  32. GRB070521: Gemini Observations
  33. GROND upper limits of GRB 070521
  34. GRB 070521 Milagro GeV/TeV Observations
  35. GRB 070520B: SARA upper limit
  36. GRB 070520A: SARA upper limit
  37. GRB 070521: SARA upper limit
  38. GRB 070521: Subaru observations and possible host detection
  39. GRB070518: Optical/NIR observation
  40. GRB 070520B: Swift/UVOT Upper Limits
  41. GRB 070520A: Subaru Observations
  42. GRB 070521, Swift-BAT refined analysis
  43. GRB 070520A: Swift UVOT Upper Limits
  44. GRB 070520B: Swift-XRT refined analysis
  45. GRB070521: P200 Observations
  46. GRB070521 : Faulkes Telescope North Observations
  47. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  48. GRB 070520A: MITSuME Akeno optical upper limits
  49. GRB 070520B, Swift-BAT refined analysis
  50. GRB 070520A, Swift-BAT refined analysis
  51. GRB 070520A: Swift-XRT refined analysis
  52. GRB 070518: TNG observations
  53. GRB 070520: Xinglong EST optical Upper Limit
  54. VLA observation of GRB 070518
  55. GRB 070518: Swift-XRT refined analysis
  56. GRB 070517: Gemini optical imaging
  57. GRB070518: UVOT refined analysis
  58. GRB 070518, Swift-BAT refined analysis
  59. GRB 070518: OT confirmed form Xinglong TNT observation
  60. GRB070517: Swift-XRT Refined Analysis
  61. GRB 070517, Swift-BAT refined analysis
  62. GRB 070509: objects inside XRT error circle
  63. GRB070419A: optical observations
  64. GRB 070419A, Deep LBT photometry
  65. GRB 070509: Swift/UVOT Upper Limits
  66. Konus-Wind and Konus-A observation of GRB 070508
  67. Swift-BAT trigger 278987 is not a GRB
  68. GRB070509: Swift-XRT Refined Analysis
  69. RHESSI Spectrum of GRB070508
  70. GRB 070508: OA fading and tentative redshift
  71. GRB 070509, Swift-BAT refined analysis
  72. GRB 070508: Suzaku/WAM observation of the prompt emission
  73. GRB 070509: REM observations
  74. GRB 070509: ROTSE-III Optical Limits
  75. GRB070508: Swift/UVOT Observations
  76. GRB 070508, SMARTS optical afterglow observation
  77. GRB 070508, Swift-BAT refined analysis
  78. GRB 070508: Multicolor optical observations and possible redshift limit
  79. GRB 070508: Swift-XRT refined analysis
  80. GRB 070508: Optical observation limiting magnitude
  81. GRB 070508: Optical afterglow detection
  82. GRB 070508: REM observations
  83. GRB070412: MAGIC telescope GeV observation
  84. Swift-BAT trigger 278809 is not a GRB
  85. GRB 070506: VLT redshift
  86. GRB070506: Swift/UVOT Observations
  87. GRB070506: Swift XRT refined analysis
  88. GRB 070506, Swift-BAT Refined Analysis
  89. GRB 070412, deep LBT imaging
  90. GRB 070429A: Swift XRT further analysis
  91. GRB070429B: VLT observations
  92. GRB 070429A: optical observations
  93. GRB070429B: position correction
  94. GRB 070309: Swift-XRT afterglow confirmation
  95. GRB070429B: possible host galaxy detection
  96. VLA observation of GRB 070429B
  97. Swift/UVOT observations of GRB070429B
  98. GRB 070429B, Swift-BAT refined analysis
  99. Swift/UVOT observations of GRB070429A
  100. GRB 070429A: Swift XRT refined analysis

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