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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"

36076 results found.

  1. GRB 110205A: Enhanced Swift-XRT position
  2. GRB 110205A: FAST Redshift
  3. GRB 110205A: GRAS005 optical observations
  4. GRB 110205A: PAIRITEL NIR Afterglow Detection
  5. GRB 110205A: Possible Lick/Kast redshift
  6. GRB 110205A: Swift/UVOT Confirmation of Flaring Afterglow
  7. GRB 110205A: Liverpool Telescope Afterglow Confirmation
  8. GRB 110205A: TAROT Calern observatory detection of an optical flare
  9. GRB 110205A: ROTSE-III, Optical Counterpart is flaring to ~14 mag
  10. GRB 110205A: TAROT Calern observatory optical detection
  11. GRB 110205A: Swift detection of a burst with an optical candidate
  12. GRB 110128A: Fermi GBM detection
  13. GRB 110201A: Swift-XRT refined Analysis
  14. GRB110201A: MITSuME Okayama optical upper limits
  15. Swift/UVOT observations of GRB110201A
  16. GRB 110201A: Swift-BAT refined analysis
  17. GRB 110201A: MASTER optical observations
  18. GRB 110201A: Swift detection of a burst
  19. GRB110112B: EVLA Observations
  20. GRB101224A: EVLA Observations
  21. GRB110112A: EVLA Observations
  22. GRB110128A: MITSuME Okayama optical upper limits
  23. GRB 110125A: Fermi GBM detection
  24. GRB 101112A: Maidanak and CrAO optical observations
  25. GRB110128A: TNG NIR observations
  26. GRB 110128A, Swift-BAT refined analysis
  27. GRB 110128A: TAROT-Calern refined analysis
  28. GRB 110128A: Swift/UVOT observations
  29. GRB 110128A: Swift-XRT refined Analysis
  30. GRB 110120A: Suzaku WAM observation of the prompt emission
  31. GRB 110128A: WHT redshifts of nearby field galaxies
  32. GRB 110128A: VLT/X-shooter redshift
  33. GRB 110128A: Enhanced Swift-XRT position
  34. GRB 110128A: Afterglow detection from NOT
  35. GRB 110128A: TAROT Calern observatory upper limits
  36. GRB 110128A: Swift detection of a burst
  37. IBAS Alerts n. 6130 and 6131 are not due to a GRB
  38. Konus-Wind observation of GRB 110120A
  39. GRB 110123A: Fermi GBM detection
  40. GRB 110106B, radio observations
  41. GRB 110120A: MASTER optical observations
  42. GRB 110120A: Fermi LAT detection
  43. GRB 101224A, the review of the sky area in plate archives
  44. IPN triangulation of GRB 110120A
  45. GRB 101225A: CQUEAN optical observation
  46. GRB 110106A: CrAO optical observations
  47. GRB 110119A: Fermi GBM detection
  48. GRB 110120A: Fermi GBM detection
  49. GRB 110119A: Suzaku WAM observation of the prompt emission
  50. GRB 110112A: optical upper limit
  51. GRB 110120A: MASTER optical observations
  52. GRB110119: Swift/UVOT Detection
  53. GRB 110119A: Swift-XRT refined Analysis
  54. GRB110119A: MITSuME Okayama optical upper limits
  55. GRB 110119A: Swift-BAT refined analysis
  56. GRB 110119A: PAIRITEL NIR Afterglow Detection
  57. GRB 110119A: Enhanced Swift-XRT position
  58. GRB 110119A: Swift detection of a burst with an optical detection
  59. GRB110106A, mm-radio observations
  60. GRB 101219B: tentative redshift and spectroscopic supernova detection
  61. GRB 101219B: GROND detection of a SN signature
  62. GRB 101219B: correction
  63. GRB 101219B: Likely the GRB host emission dominates now in the uvw2 filter
  64. New feature in Fermi GBM GRB Ground Position Notices
  65. Swift-BAT Trigger 442539 is not a GRB
  66. Swift Trigger 442539 is probably not a GRB
  67. Short GRB 110112B : early optical limit by "Pi of the Sky"
  68. GRB101225A - timing analysis
  69. GRB 110112B: Fermi GBM observation
  70. The Christmas burst GRB 101225A - optical spectroscopy with GTC
  71. GRB 110112B: Swift XRT and UVOT observations of the INTEGRAL burst
  72. GRB 110112A: MITSuME Akeno and Okayama optical upper limits
  73. GRB 110107A: Swift-XRT afterglow confirmation
  74. GRB 101225A: HST observations - no host detected
  75. GRB 101225A: Redshift retraction and results of additional photometric follow-up at the NOT
  76. GRB 110112B: A short GRB detected by INTEGRAL
  77. GRB 110112A: Swift-XRT refined Analysis
  78. GRB 110112A: Swift/UVOT upper limits
  79. GRB 110112A: WHT candidate afterglow/host galaxy
  80. GRB 110112A: MASTER optical observations
  81. GRB 110112A: Swift-BAT refined analysis
  82. GRB 110112A: Enhanced Swift-XRT position
  83. GRB 110106B: MASTER optical observations
  84. GRB110112A: TNT optical afterglow candidate
  85. GRB 110112A: Swift detection of a possible short burst
  86. GRB 110106B: early optical and near-IR observations
  87. GRB 110107A: Swift/UVOT upper limits
  88. GRB 101225a
  89. GRB 101219b. Possible radio afterglow detection.
  90. GRB 110106B: MASTER early optical observations
  91. GRB 110107A: Swift-XRT Afterglow Candidate
  92. GRB 110107A: Swift-BAT refined analysis
  93. GRB 110107A detected in ground analysis of BAT slew data
  94. GRB 101213A: Gemini-N galaxy redshift
  95. GRB 110106B: Fermi GBM detection
  96. Short GRB 110106A: MASTER OT observations
  97. GRB 110106B: Swift-XRT refined Analysis
  98. GRB 110106B: Gemini-North / WHT detection of a fading afterglow
  99. GRB 110106A: TNG NIR observations
  100. GRB 110106B Gemini-N galaxy redshift

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