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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"

23410 results found.

  1. GRB 060210 : Xinglong and Lulin optical limit
  2. GRB 060210: Swift detection of a burst
  3. GRB060210: Optical afterglow
  4. GRB 060206: Swift/UVOT Observations
  5. GRB 060209 : TAROT optical observation
  6. GRB 060209(?): Swift-BAT detection of a possible burst
  7. GRB 060203: Swift/UVOT upper limits
  8. GRB 060206: TTT Observations
  9. GRB 060121 : WIDGET Pre-trigger limit
  10. GRB 060206: Tenagra II Observations
  11. GRB060204a: Swift XRT Source is not GRB Afterglow
  12. GRB 060206: IR Detection of the Afterglow
  13. GRB 060206: Lick 3m Spectroscopy
  14. GRB060204A: Swift/UVOT observations
  15. GRB060206: SDSS Pre-Burst Observations
  16. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  17. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  18. GRB060206: Swift-BAT detection of a burst
  19. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  20. GRB060204C: optical observation
  21. GRB 060204A: Swift XRT upper limit
  22. GRB 060204A: FRAM optical observations
  23. GRB060204B: Swift/UVOT refined analysis
  24. GRB 060204C: optical observations
  25. Swift XRT Observation of GRB 060204C
  26. GRB 060204B: ART early limit
  27. GRB060204B: Swift XRT Team Refined Analysis
  28. GRB 060204b: Keck/LRIS Afterglow Confirmation
  29. GRB 060204C: BOOTES-IR optical limits
  30. GRB 060204C: Liverpool Telescopes optical limit
  31. GRB 060204C: ROTSE-III Optical Limits
  32. GRB 060204C: Swift-BAT detection of a burst
  33. GRB 060124: Radio Observations
  34. GRB 060204B: ART optical limit
  35. GRB060204B, optical observation
  36. GRB060204B - SDSS pre-burst observations
  37. GRB 060204B: Swift detection of a burst
  38. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  39. GRB 060203: RTT150 optical observations
  40. GRB060203 - Swift UVOT observation
  41. GRB 060203: IR Counterpart
  42. Possible GRB 060203: optical observations at Asiago
  43. GRB 060202: PROMPT Observations
  44. GRB 060202: GETS observation
  45. GRB 060202: Gemini-N J, H, K_s observations
  46. GRB 060202 : Kiso B and R band limit
  47. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  48. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  49. GRB060202, optical observation
  50. GRB 060202: Swift/UVOT upper limits
  51. GRB 060202 : Lulin R and I band limit
  52. GRB 060202: Swift detection of a burst
  53. GRB 060121: Gemini Late-time Observations
  54. GRB 060130: PROMPT Observations
  55. GRB060130: Further R-band imaging
  56. GRB 060130: Swift/XRT observation
  57. GRB 060123: Gemini spectroscopy of the putative host galaxy
  58. GRB 060123: VLA Radio Observations
  59. GRB060130: Optical imaging
  60. GRB060130: REM infrared observations
  61. GRB 060130, SMARTS optical observations
  62. GRB 060130: FRAM optical observations
  63. GRB 060121: Confirmation of NIR Afterglow
  64. GRB060124, BVRcIc field calibration
  65. GRB 060121: Probable Detection of NIR Afterglow
  66. GRB060124: optical observation
  67. GRB 060116 HST observations
  68. GRB 060124: ART optical limits during the burst
  69. GRB060123: Optical and IR Imaging
  70. GRB 060123: P200 Observations
  71. GRB 060124: R band Observations
  72. GRB 060124 : Optical observation at Xinglong and Kiso
  73. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  74. GRB060123: SDSS pre-burst observations
  75. GRB 060123: Swift detection of a very long, faint burst
  76. GRB 060121: OHP optical limits
  77. GRB 060124: TAROT optical limits
  78. GRB060124, optical observation
  79. GRB 050124 : Kiso Optical limit
  80. GRB 060124: Optical Observations at Tautenburg
  81. GRB 060124: Swift-BAT detection of a burst
  82. GRB 060121: Liverpool Telescopes optical limits
  83. GRB 060121: I-band Limits
  84. GRB 060121: candidate optical counterpart
  85. GRB 060121: Infrared Observations
  86. GRB 060121: optical observations
  87. GRB 060121: Optical imaging
  88. GRB060121 - SDSS pre-burst observations
  89. HETE Alert 4006: MASTER promt optical limit
  90. GRB 060117: PROMPT Observations
  91. GRB060117 - ATCA 3/6cm radio limits - correction
  92. GRB060117 - ATCA 3/6cm radio limits
  93. GRB 060116: UKIRT IR Observations
  94. GRB 060116: PROMPT Observations
  95. GRB 060117: FRAM optical afterglow candidate
  96. GRB 060117: nearby galaxy
  97. GRB 060117: Swift-BAT detection of a bright burst
  98. GRB 060116: VLT optical observations
  99. GRB 060115: PROMPT Observations
  100. GRB 060116: XRT refined analysis

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