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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"

19546 results found.

  1. GRB 060210: Swift detection of a burst
  2. GRB060210: Optical afterglow
  3. GRB 060209 : TAROT optical observation
  4. GRB 060209(?): Swift-BAT detection of a possible burst
  5. GRB 060206: WSRT Radio Observations
  6. GRB 060203: Swift/UVOT upper limits
  7. GRB 060121 : WIDGET Pre-trigger limit
  8. GRB060204a: Swift XRT Source is not GRB Afterglow
  9. GRB 060206: IR Detection of the Afterglow
  10. GRB 060204A: ROSAT Pointing
  11. GRB060204A: Swift/UVOT observations
  12. GRB 060206: Swift-BAT refined analysis
  13. GRB060206: SDSS Pre-Burst Observations
  14. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  15. GRB060206: Swift-BAT detection of a burst
  16. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  17. GRB060204C: optical observation
  18. GRB 060204A: Swift XRT upper limit
  19. GRB 060204A: FRAM optical observations
  20. GRB060204B: Swift/UVOT refined analysis
  21. GRB 060204C: optical observations
  22. Swift XRT Observation of GRB 060204C
  23. GRB 060204B: ART early limit
  24. GRB 060204b: Keck/LRIS Afterglow Confirmation
  25. GRB 060204C: Liverpool Telescopes optical limit
  26. GRB 060204C: Swift-BAT detection of a burst
  27. GRB060204B, optical observation
  28. GRB060204B - SDSS pre-burst observations
  29. GRB 060204B: Swift detection of a burst
  30. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  31. GRB 060203: RTT150 optical observations
  32. GRB 060203: IR Counterpart
  33. Possible GRB 060203: optical observations at Asiago
  34. GRB 060202: Gemini-N J, H, K_s observations
  35. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  36. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  37. GRB060202, optical observation
  38. GRB 060202: Swift/UVOT upper limits
  39. GRB 060202: Swift XRT Team Refined Analysis
  40. GRB 060202: Swift detection of a burst
  41. GRB 060121: Gemini Late-time Observations
  42. GRB060130: Further R-band imaging
  43. GRB 060130: Swift/XRT observation
  44. GRB 060123: Gemini spectroscopy of the putative host galaxy
  45. GRB060130: Optical imaging
  46. GRB060130: REM infrared observations
  47. GRB 060130, SMARTS optical observations
  48. GRB 060130: FRAM optical observations
  49. GRB 060130: further INTEGRAL IBIS results
  50. Possible GRB 051221B: MDM Correction
  51. GRB 060121: Confirmation of NIR Afterglow
  52. GRB060124, BVRcIc field calibration
  53. GRB060105: refined analysis of the Suzaku observation
  54. GRB 060121: Probable Detection of NIR Afterglow
  55. GRB 060116 HST observations
  56. GRB 060124: ART optical limits during the burst
  57. GRB060123: Optical and IR Imaging
  58. GRB 060123: P200 Observations
  59. GRB 060124: R band Observations
  60. GRB 060124 : Optical observation at Xinglong and Kiso
  61. GRB060123: SDSS pre-burst observations
  62. GRB 060121: OHP optical limits
  63. GRB 060124: TAROT optical limits
  64. GRB060124, optical observation
  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: candidate optical counterpart
  69. GRB 060121: Infrared Observations
  70. GRB 060121: optical observations
  71. GRB 060121: Optical imaging
  72. GRB060121 - SDSS pre-burst observations
  73. GRB 060121: A bright short/hard GRB localized by HETE-2 WXM
  74. HETE Alert 4006: MASTER promt optical limit
  75. GRB060117 - ATCA 3/6cm radio limits - correction
  76. GRB060117 - ATCA 3/6cm radio limits
  77. GRB 060116: possible I-J dropout
  78. GRB 060116: UKIRT IR Observations
  79. GRB 060117: FRAM optical afterglow candidate
  80. GRB 060117: nearby galaxy
  81. GRB 060116: VLT optical observations
  82. GRB 060116: IR Candidate Afterglow
  83. GRB 060116: Swift/UVOT upper limits
  84. GRB060115: REM observations
  85. GRB060116: Faulkes North observation
  86. GRB 060116: Swift-BAT detection of a burst
  87. GRB 060115: Swift/UVOT upper limits
  88. GRB 060114: REM observations
  89. GRB 060114: Swift/UVOT Observations
  90. GRB060115, optical observation
  91. GRB 060115: MITSuME optical afterglow candidate
  92. GRB 060115: Swift detection of a burst
  93. GRB060114, optical observation
  94. GRB060114: Faulkes North observation
  95. GRB 060108: IR observations of afterglow
  96. GRB 060108: Evidence for an XRT Position Offset
  97. GRB 060110: KAIT observations
  98. GRB 060111B: MITSuME detection of optical afterglow
  99. GRB 060111B: TAROT optical observation
  100. GRB060111A: RTT150 optical observations

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