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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"

20885 results found.

  1. GRB 060204B: ART early limit
  2. GRB060204B: Swift XRT Team Refined Analysis
  3. GRB 060204b: Keck/LRIS Afterglow Confirmation
  4. GRB 060204C: BOOTES-IR optical limits
  5. GRB 060204C: Liverpool Telescopes optical limit
  6. GRB 060204C: ROTSE-III Optical Limits
  7. GRB 060204C: Swift-BAT detection of a burst
  8. GRB 060124: Radio Observations
  9. GRB 060204B: ART optical limit
  10. GRB060204B, optical observation
  11. GRB060204B - SDSS pre-burst observations
  12. GRB 060204B: Swift detection of a burst
  13. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  14. GRB 060203: RTT150 optical observations
  15. GRB060203 - Swift UVOT observation
  16. GRB 060203: IR Counterpart
  17. Possible GRB 060203: optical observations at Asiago
  18. GRB 060202: PROMPT Observations
  19. GRB 060202: GETS observation
  20. GRB 060202: Gemini-N J, H, K_s observations
  21. GRB 060202 : Kiso B and R band limit
  22. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  23. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  24. GRB060202, optical observation
  25. GRB 060202: Swift/UVOT upper limits
  26. GRB 060202 : Lulin R and I band limit
  27. GRB 060202: Swift detection of a burst
  28. GRB 060121: Gemini Late-time Observations
  29. GRB 060130: PROMPT Observations
  30. GRB060130: Further R-band imaging
  31. GRB 060130: Swift/XRT observation
  32. GRB 060123: Gemini spectroscopy of the putative host galaxy
  33. GRB 060123: VLA Radio Observations
  34. GRB060130: Optical imaging
  35. GRB060130: REM infrared observations
  36. GRB 060130, SMARTS optical observations
  37. GRB 060130: FRAM optical observations
  38. GRB 060121: Confirmation of NIR Afterglow
  39. GRB060124, BVRcIc field calibration
  40. GRB 060121: Probable Detection of NIR Afterglow
  41. GRB060124: optical observation
  42. GRB 060116 HST observations
  43. GRB 060124: ART optical limits during the burst
  44. GRB060123: Optical and IR Imaging
  45. GRB 060123: P200 Observations
  46. GRB 060124: R band Observations
  47. GRB 060124 : Optical observation at Xinglong and Kiso
  48. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  49. GRB060123: SDSS pre-burst observations
  50. GRB 060123: Swift detection of a very long, faint burst
  51. GRB 060121: OHP optical limits
  52. GRB 060124: TAROT optical limits
  53. GRB060124, optical observation
  54. GRB 050124 : Kiso Optical limit
  55. GRB 060124: Optical Observations at Tautenburg
  56. GRB 060124: Swift-BAT detection of a burst
  57. GRB 060121: Liverpool Telescopes optical limits
  58. GRB 060121: I-band Limits
  59. GRB 060121: candidate optical counterpart
  60. GRB 060121: Infrared Observations
  61. GRB 060121: optical observations
  62. GRB 060121: Optical imaging
  63. GRB060121 - SDSS pre-burst observations
  64. HETE Alert 4006: MASTER promt optical limit
  65. GRB 060117: PROMPT Observations
  66. GRB060117 - ATCA 3/6cm radio limits - correction
  67. GRB060117 - ATCA 3/6cm radio limits
  68. GRB 060116: UKIRT IR Observations
  69. GRB 060116: PROMPT Observations
  70. GRB 060117: FRAM optical afterglow candidate
  71. GRB 060117: nearby galaxy
  72. GRB 060117: Swift-BAT detection of a bright burst
  73. GRB 060116: VLT optical observations
  74. GRB 060115: PROMPT Observations
  75. GRB 060116: XRT refined analysis
  76. GRB 060116: IR Candidate Afterglow
  77. GRB 060116: Swift/UVOT upper limits
  78. GRB060115: REM observations
  79. GRB 060116 : Lulin optical limit
  80. GRB 060116: ROTSE-III Optical Limits
  81. GRB060116: Faulkes North observation
  82. GRB 060116: Swift-BAT detection of a burst
  83. GRB 060115: Swift/UVOT upper limits
  84. GRB 060114: REM observations
  85. GRB 060115: Swift XRT refined analysis
  86. GRB 060114: Swift/UVOT Observations
  87. GRB060115, optical observation
  88. GRB 060115: MITSuME optical afterglow candidate
  89. GRB 060115: Swift detection of a burst
  90. GRB 060114: Swift XRT upper limit
  91. GRB060114, optical observation
  92. GRB 060114: A long GRB detected by INTEGRAL
  93. GRB060114: Faulkes North observation
  94. GRB 060108: IR observations of afterglow
  95. GRB 060108: Evidence for an XRT Position Offset
  96. GRB 060110: KAIT observations
  97. GRB 060111A: refined UVOT anaysis
  98. GRB 060111B: MITSuME detection of optical afterglow
  99. GRB 060111B: TAROT optical observation
  100. GRB060111A: RTT150 optical observations

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