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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"

22095 results found.

  1. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  2. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  3. GRB060206: Swift-BAT detection of a burst
  4. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  5. GRB060204C: optical observation
  6. GRB 060204A: Swift XRT upper limit
  7. GRB 060204A: FRAM optical observations
  8. GRB060204B: Swift/UVOT refined analysis
  9. GRB 060204C: optical observations
  10. Swift XRT Observation of GRB 060204C
  11. GRB 060204B: ART early limit
  12. GRB060204B: Swift XRT Team Refined Analysis
  13. GRB 060204b: Keck/LRIS Afterglow Confirmation
  14. GRB 060204C: BOOTES-IR optical limits
  15. GRB 060204C: Liverpool Telescopes optical limit
  16. GRB 060204C: ROTSE-III Optical Limits
  17. GRB 060204C: Swift-BAT detection of a burst
  18. GRB 060124: Radio Observations
  19. GRB 060204B: ART optical limit
  20. GRB060204B, optical observation
  21. GRB060204B - SDSS pre-burst observations
  22. GRB 060204B: Swift detection of a burst
  23. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  24. GRB 060203: RTT150 optical observations
  25. GRB060203 - Swift UVOT observation
  26. GRB 060203: IR Counterpart
  27. Possible GRB 060203: optical observations at Asiago
  28. GRB 060202: PROMPT Observations
  29. GRB 060202: GETS observation
  30. GRB 060202: Gemini-N J, H, K_s observations
  31. GRB 060202 : Kiso B and R band limit
  32. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  33. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  34. GRB060202, optical observation
  35. GRB 060202: Swift/UVOT upper limits
  36. GRB 060202 : Lulin R and I band limit
  37. GRB 060202: Swift detection of a burst
  38. GRB 060121: Gemini Late-time Observations
  39. GRB 060130: PROMPT Observations
  40. GRB060130: Further R-band imaging
  41. GRB 060130: Swift/XRT observation
  42. GRB 060123: Gemini spectroscopy of the putative host galaxy
  43. GRB 060123: VLA Radio Observations
  44. GRB060130: Optical imaging
  45. GRB060130: REM infrared observations
  46. GRB 060130, SMARTS optical observations
  47. GRB 060130: FRAM optical observations
  48. GRB 060121: Confirmation of NIR Afterglow
  49. GRB060124, BVRcIc field calibration
  50. GRB 060121: Probable Detection of NIR Afterglow
  51. GRB060124: optical observation
  52. GRB 060116 HST observations
  53. GRB 060124: ART optical limits during the burst
  54. GRB060123: Optical and IR Imaging
  55. GRB 060123: P200 Observations
  56. GRB 060124: R band Observations
  57. GRB 060124 : Optical observation at Xinglong and Kiso
  58. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  59. GRB060123: SDSS pre-burst observations
  60. GRB 060123: Swift detection of a very long, faint burst
  61. GRB 060121: OHP optical limits
  62. GRB 060124: TAROT optical limits
  63. GRB060124, optical observation
  64. GRB 050124 : Kiso Optical limit
  65. GRB 060124: Optical Observations at Tautenburg
  66. GRB 060124: Swift-BAT detection of a burst
  67. GRB 060121: Liverpool Telescopes optical limits
  68. GRB 060121: I-band Limits
  69. GRB 060121: candidate optical counterpart
  70. GRB 060121: Infrared Observations
  71. GRB 060121: optical observations
  72. GRB 060121: Optical imaging
  73. GRB060121 - SDSS pre-burst observations
  74. HETE Alert 4006: MASTER promt optical limit
  75. GRB 060117: PROMPT Observations
  76. GRB060117 - ATCA 3/6cm radio limits - correction
  77. GRB060117 - ATCA 3/6cm radio limits
  78. GRB 060116: UKIRT IR Observations
  79. GRB 060116: PROMPT Observations
  80. GRB 060117: FRAM optical afterglow candidate
  81. GRB 060117: nearby galaxy
  82. GRB 060117: Swift-BAT detection of a bright burst
  83. GRB 060116: VLT optical observations
  84. GRB 060115: PROMPT Observations
  85. GRB 060116: XRT refined analysis
  86. GRB 060116: IR Candidate Afterglow
  87. GRB 060116: Swift/UVOT upper limits
  88. GRB060115: REM observations
  89. GRB 060116 : Lulin optical limit
  90. GRB 060116: ROTSE-III Optical Limits
  91. GRB060116: Faulkes North observation
  92. GRB 060116: Swift-BAT detection of a burst
  93. GRB 060115: Swift/UVOT upper limits
  94. GRB 060114: REM observations
  95. GRB 060115: Swift XRT refined analysis
  96. GRB 060114: Swift/UVOT Observations
  97. GRB060115, optical observation
  98. GRB 060115: MITSuME optical afterglow candidate
  99. GRB 060115: Swift detection of a burst
  100. GRB 060114: Swift XRT upper limit

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