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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"

20357 results found.

  1. GRB 090313: Swift detection of a burst
  2. GRB 090313: Swift detection of a burst
  3. Swift trigger 346250 is probably not a burst
  4. GRB 090205: Zadko Telescope late-time observations
  5. GRB 090309A: GROND upper limits
  6. GRB 090307A: TAROT Calern observatory optical observations
  7. GRB 090309: Swift/UVOT Upper Limits
  8. GRB 090309: Enhanced Swift-XRT position
  9. GRB 090308: GROND observations
  10. GRB 090308: Gemini GMOS Observations
  11. GRB 090309: Swift detection of a burst
  12. GRB 090308: Swift/UVOT Upper Limits
  13. GRB 090307: GROND Upper Limits
  14. GRB 090306B: GROND Upper Limits
  15. GRB 090308: Swift-XRT refined analysis
  16. GRB 090308: Swift detection of a burst
  17. GRB 090306B: Possible XRT afterglow
  18. GRB 090307: Swift-XRT afterglow confirmation and analysis
  19. Swift Trigger 345551 is probably not a GRB
  20. IPN localization of short GRB 090305C
  21. GRB 090306: Swift detection of a possible burst
  22. GRB 090305: Swift/UVOT Upper Limits
  23. GRB 090305: Swift-XRT refined analysis
  24. GRB090305: GMOS-S Candidate Optical Afterglow
  25. GRB 090305: Swift detection of a short burst
  26. Konus-Wind observation of bright short GRB 090227B
  27. Konus-Wind observation of GRB 090301A
  28. GRB 081211B: Nearby cluster
  29. Ongoing activity of AXP/SGR 1E1547.0-5408
  30. GRB090217: XRT analysis
  31. Konus-Wind observation of GRB 090217
  32. SGR activity seen by BAT during ICSP Ionospheric Events
  33. VLA radio upper limit on GRB 090205
  34. GRB 090205: Swift/UVOT Upper Limits
  35. GRB 090205: GROND observations and photometric redshift estimate
  36. GRB 090205: VLT candidate afterglow
  37. GRB 090205: Enhanced Swift-XRT position
  38. GRB 090205: Swift detection of a burst
  39. GRB090201: Swift UVOT upper limits
  40. GRB 090201: object inside the enhanced XRT error circle
  41. GRB 090201: Enhanced Swift-XRT position
  42. GRB 090201: VLT NIR observations
  43. GRB 090201: Swift-BAT refined analysis
  44. GRB 090201: VLT afterglow candidate
  45. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  46. GRB 090201: ROTSE-III Optical Limits
  47. GRB 090126A: Swift/UVOT Upper Limits
  48. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  49. Suzaku ToO Observation of AXP 1E 1547.0-5408
  50. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  51. GRB 090102: HST observations and host galaxy
  52. GRB 090118: no afterglow candidate
  53. GRB 090123: GROND detection
  54. GRB 090123: Swift/UVOT Observations
  55. GRB090123: Enhanced Swift-XRT position
  56. GRB 090123: Swift detection of a burst
  57. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  58. Trigger 340734: Swift detection of a possible short burst
  59. AXP 1E1547.0-5408 activity with SGR bursts
  60. GRB 090118: Subaru NIR Observation
  61. GRB 090118: KPNO 4m 2nd Epoch Observations
  62. GRB 090118 (BATSS): GRT Optical Observation
  63. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  64. GRB090118 Swift/UVOT upper limits
  65. GRB 090118: GROND Upper Limits
  66. GRB 090118: Possible burst detection from Swift-BAT slew data
  67. GRB 090117 - Fermi GBM Observations
  68. GRB 090117: GROND Upper Limits
  69. GRB090117 Swift/UVOT upper limits
  70. GRB090117: Swift-XRT detection of a possible candidate afterglow
  71. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  72. GRB 090113: Swift UVOT upper limits
  73. GRB 090113: GROND Upper Limits
  74. GRB 090113: Observations from NOT
  75. GRB 090113: Enhanced Swift-XRT position
  76. GRB 090113: ROTSE-III Optical Limits
  77. GRB 090113: Swift detection of a burst
  78. GRB 090112: Fermi GBM detection
  79. GRB 090111: Swift UVOT Upper Limits
  80. GRB 090111: Swift-XRT refined analysis
  81. GRB 090111: Enhanced Swift-XRT position
  82. GRB 090111: Swift detection of a burst
  83. GRB 090107B: Swift XRT afterglow confirmation
  84. GRB 090107B: Swift/UVOT Observations
  85. GRB 090107B: Swift-XRT detection of possible afterglow
  86. VLA radio upper limit on GRB 090102
  87. GRB 090102: GRT Optical Observation
  88. Swift triggered on the HMXB 1A 1118-61
  89. GRB 090102: P60 Imaging and P200 Spectroscopy
  90. GRB 090102 Observations from IAC80
  91. GRB 090102: GROND observations of the optical afterglow
  92. GRB 090102: Swift-BAT refined analysis
  93. GRB 090102: NOT redshift
  94. GRB 090102: Enhanced Swift-XRT position
  95. GRB 090102: REM observations of a bright afterglow
  96. GRB 090102: Swift detection of a burst with an optical counterpart
  97. GRB 090102: TAROT Calern observatory optical observations
  98. GRB 081230: GROND confirmation of the afterglow
  99. GRB081230: Swift-XRT refined analysis
  100. GRB 081230 Swift/UVOT Observations

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