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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"

28101 results found.

  1. Orphan GRB Afterglow candidate
  2. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  3. GRB 060206: Subaru/FOCAS optical spectroscopy
  4. GRB 060206: IR Detection of the Afterglow
  5. GRB 060206: Lick 3m Spectroscopy
  6. GRB 060204A: ROSAT Pointing
  7. GRB 060206: Super-LOTIS observations
  8. GRB060204A: Swift/UVOT observations
  9. GRB 060206 : Lulin optical observations
  10. GRB060206: Swift XRT Refined Analysis
  11. GRB060206: Liverpool Telescope observation
  12. GRB 060206: Spectroscopic Redshift
  13. GRB060206: P60 Optical Observations
  14. GRB 060206: KAIT observations
  15. GRB060206: Swift XRT Position
  16. GRB060206: SARA Detection
  17. GRB 060206: RAPTOR observations of afterglow candidate variability.
  18. GRB 060206: High redshift burst
  19. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  20. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  21. GRB060206: Optical afterglow
  22. GRB060206: Swift-BAT detection of a burst
  23. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  24. BAT GRB 060204C is probably not a GRB
  25. GRB 060204B: BVRi-band detections of optical afterglow
  26. GRB 060204A: Swift XRT upper limit
  27. GRB060204B: Swift/UVOT refined analysis
  28. GRB 060204C: optical observations
  29. Swift XRT Observation of GRB 060204C
  30. GRB 060204B: ART early limit
  31. GRB060204B: Swift XRT Team Refined Analysis
  32. GRB 060204b: Keck/LRIS Afterglow Confirmation
  33. GRB 060204C: Liverpool Telescopes optical limit
  34. GRB 060204C: Swift-BAT detection of a burst
  35. GRB 060124: Radio Observations
  36. GRB060204B: Faulkes OT candidate
  37. GRB 060204B: ART optical limit
  38. GRB 060204B: Swift detection of a burst
  39. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  40. GRB 060203: RTT150 optical observations
  41. GRB060203: Swift XRT Team Refined Analysis
  42. GRB060203 - Swift UVOT observation
  43. Swift-BAT trigger is GRB 060203
  44. GRB 060203: IR Counterpart
  45. GRB 060203: P60 Confirmation of Optical Afterglow
  46. Possible GRB 060203: candidate optical counterpart
  47. Swift BAT Trigger 180151: Swift XRT source detection
  48. Swift-BAT trigger 180151 is unknown origin at this time
  49. GRB 060202: GETS observation
  50. GRB 060202: Gemini-N J, H, K_s observations
  51. GRB 060202 : Kiso B and R band limit
  52. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  53. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  54. GRB 060202: Refined analysis of the Swift-BAT burst
  55. GRB 060202: Swift/UVOT upper limits
  56. GRB 060202: Swift XRT Team Refined Analysis
  57. GRB 060202 : Lulin R and I band limit
  58. GRB060202: Faulkes North observation
  59. GRB 060202: Swift detection of a burst
  60. GRB 060121: Gemini Late-time Observations
  61. GRB 060130: Swift/XRT observation
  62. GRB 051211A: MDM Observations
  63. GRB 060123: Gemini spectroscopy of the putative host galaxy
  64. GRB 060123: VLA Radio Observations
  65. GRB060130: Optical imaging
  66. GRB 060130, SMARTS optical observations
  67. Possible GRB 051221B: MDM Correction
  68. GRB 060121: Confirmation of NIR Afterglow
  69. GRB060124: optical observation
  70. GRB060124: optical observations
  71. GRB 060123: Swift refined analysis of an unusual GRB
  72. GRB060124, BVRcIc field calibration
  73. GRB060105: refined analysis of the Suzaku observation
  74. GRB 060121: Probable Detection of NIR Afterglow
  75. GRB060124: optical observation
  76. GRB 060116 HST observations
  77. GRB 060124: HETE detection and spectrum of the main peak
  78. Refined XRT Position for GRB 060123
  79. GRB060124: detailed XRT analysis
  80. GRB 060124: ART optical limits during the burst
  81. GRB060123: Optical and IR Imaging
  82. GRB 060123: P200 Observations
  83. GRB 060124: Keck optical spectrum
  84. GRB 060124: MDM Optical Spectrum
  85. GRB 060124: XRT refined analysis
  86. GRB 060123: Swift detection of a very long, faint burst
  87. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  88. GRB 060124: Confirmation of the Afterglow
  89. GRB 060124: XRT position
  90. GRB 060124: Optical Afterglow Candidate from Tautenburg
  91. GRB 060124: Optical Observations at Tautenburg
  92. GRB 060124: Swift-BAT detection of a burst
  93. GRB 060116: Radio Detection
  94. GRB 060121: Swift/UVOT upper limits
  95. GRB 060121: Liverpool Telescopes optical limits
  96. GRB 060121: Swift XRT refined analysis
  97. GRB 060121: I-band Limits
  98. GRB 060121: Confirmation of Afterglow
  99. GRB 060121: candidate optical counterpart
  100. GRB 060121: Swift XRT refined position

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