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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"

19090 results found.

  1. GRB 090320B: MASTER-Net prompt optical observations
  2. GRB 090323: Fermi GBM Spectral Analysis
  3. GRB 090323 TLS detection - still bright
  4. GRB 090323: UVOT Detection of Afterglow
  5. GRB 090323: P60 Afterglow Confirmation
  6. GRB 090323: GROND Detection of the Afterglow and Photo-z
  7. GRB 090323: Possible XRT Counterpart
  8. GRB 090320C: Fermi GBM Detection
  9. GRB 090320B: Fermi GBM detection.
  10. GRB 090319: Fermi GBM detection
  11. GRB 090320A: Fermi GBM detection
  12. Further 15GHz observations of GRB090313
  13. X-shooter observations of GRB 090313
  14. GRB090313: radio detection with the VLA
  15. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  16. Further radio observation of GRB 090313
  17. GRB 090313: detection with CARMA in 3mm band
  18. GRB090305B: MASTER-net prompt optical short burst observations
  19. GRB 090313: MITSuME Okayama observation
  20. GRB 090313: Additional Gemini-S photometry
  21. GRB 090313: TAROT La Silla observatory optical detection
  22. GRB 090313: Zadko Telescope observations
  23. GRB 090313: Ongoing plateau phase
  24. GRB 090313: Swift-XRT refined analysis
  25. GRB 090313: Swift/UVOT upper limits
  26. GRB 090313, GROND observations
  27. Swift trigger 346250 is probably not a burst
  28. GRB090310: Fermi GBM detection
  29. GRB 090205: Zadko Telescope late-time observations
  30. GRB 090309A: GROND upper limits
  31. GRB 090307A: TAROT Calern observatory optical observations
  32. GRB 090309: Swift/UVOT Upper Limits
  33. GRB090305B: Fermi GBM detection
  34. GRB 090309B: Fermi GBM detection
  35. GRB 090309: Enhanced Swift-XRT position
  36. GRB 090308: GROND observations
  37. GRB 090308: Gemini GMOS Observations
  38. GRB 090309: Swift detection of a burst
  39. GRB 090308B: Fermi GBM detection
  40. GRB 090308: Swift/UVOT Upper Limits
  41. GRB 090307B: Fermi GBM detection
  42. GRB 090306C: Fermi GBM detection
  43. GRB 090307: GROND Upper Limits
  44. GRB 090306B: GROND Upper Limits
  45. GRB 090308: Swift-XRT refined analysis
  46. GRB 090308: Swift detection of a burst
  47. GRB 090306B: Possible XRT afterglow
  48. GRB 090307: Swift-XRT afterglow confirmation and analysis
  49. GRB 090307: Swift-BAT refined analysis of trigger 345551
  50. Swift Trigger 345551 is probably not a GRB
  51. IPN localization of short GRB 090305C
  52. GRB 090306: Swift detection of a possible burst
  53. GRB 090305: Swift/UVOT Upper Limits
  54. GRB 090305: Swift-XRT refined analysis
  55. GRB090305: GMOS-S Candidate Optical Afterglow
  56. GRB 090305: Swift detection of a short burst
  57. GRB 090228B: Fermi GBM detection
  58. GRB 090301B: Fermi GBM detection
  59. GRB 090228: Fermi GBM detection
  60. GRB 090227: Fermi GBM detection
  61. GRB 090206: Fermi GBM detection
  62. GRB 081211B: Nearby cluster
  63. GRB 090222: Fermi GBM detection
  64. GRB 090219: Fermi GBM detection
  65. GRB090217: XRT analysis
  66. GRB 090217: Fermi GBM detection
  67. SGR activity seen by BAT during ICSP Ionospheric Events
  68. GRB 090207 - Fermi GBM Observations
  69. GRB 090129: Fermi GBM detection
  70. VLA radio upper limit on GRB 090205
  71. GRB 090205: Swift/UVOT Upper Limits
  72. GRB 090205: GROND observations and photometric redshift estimate
  73. GRB 090205: VLT candidate afterglow
  74. GRB 090205: Enhanced Swift-XRT position
  75. GRB 090205: Swift detection of a burst
  76. GRB 090202: Fermi GBM detection
  77. GRB 090131: Fermi GBM detection
  78. GRB090201: Swift UVOT upper limits
  79. GRB 090201: object inside the enhanced XRT error circle
  80. GRB 090201: Enhanced Swift-XRT position
  81. GRB 090201: VLT NIR observations
  82. GRB 090201: Swift-BAT refined analysis
  83. GRB 090201: VLT afterglow candidate
  84. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  85. GRB 090201: ROTSE-III Optical Limits
  86. GRB 090126A: Swift/UVOT Upper Limits
  87. Suzaku ToO Observation of AXP 1E 1547.0-5408
  88. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  89. GRB 090102: HST observations and host galaxy
  90. GRB 090126B: Fermi GBM detection
  91. GRB 090118: no afterglow candidate
  92. GRB 090123: GROND detection
  93. GRB 090123: Swift/UVOT Observations
  94. GRB090123: Enhanced Swift-XRT position
  95. GRB 090123: Swift detection of a burst
  96. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  97. Trigger 340734: Swift detection of a possible short burst
  98. GRB 090118: Subaru NIR Observation
  99. GRB 090118: KPNO 4m 2nd Epoch Observations
  100. GRB 090118 (BATSS): GRT Optical Observation

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