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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"

20242 results found.

  1. GRB060218: analysis of the XMM-Newton observation
  2. Swift/UVOT observations of GRB060306
  3. GRB 060306: Swift-XRT team refined analysis
  4. GRB 060306: Swift detection of a bright burst
  5. GRB060218: Ep,i - Eiso correlation
  6. GRB060223b: optical limit
  7. GRB 060223b: Swift/UVOT Upper Limits
  8. GRB 060218/SN 2006aj: K-380 optical observations
  9. GRB 060218/SN 2006aj, SMARTS optical/IR observations
  10. GRB200618: optical polarimetry and photometry
  11. GRB 060223B: Swift XRT possible afterglow
  12. GRB 060218/SN 2006aj: REM optical and near-infrared observations
  13. GRB 060218 : Radio upper limits from GMRT
  14. GRB 060223A:Xinglong optical limits
  15. GRB 060223a: Swift/UVOT refined analysis
  16. GRB 060223B: Swift detection of a bright burst
  17. GRB 060218: rebrightening
  18. GRB 060219: Swift-BAT refined analysis
  19. GRB 060218: Decline in r-band flux
  20. GRB060219: SARA Observations
  21. GRB 060219: Swift/UVOT Upper Limits
  22. GRB 051221B: Swift-XRT Team Refined Analysis
  23. GRB060218: Radio Afterglow Discovery
  24. GRB060219: SDSS pre-burst observations
  25. GRB 060219: Swift-BAT detection of a weak burst
  26. Oddball GRB 060218, transient or GRB?
  27. Brightening of the Optical Counterpart of the Possible GRB 060218
  28. GRB 060218: Pre-burst detection of a possible host galaxy
  29. GRB 060218A: ROTSE-III Possible Optical Flare
  30. GRB 060211B: Swift/UVOT Upper Limits
  31. GRB060218 : SDSS pre-burst observations
  32. GRB 060218: Swift XRT Position
  33. GRB 060213: optical afterglow not confirmed
  34. Swift UVOT observations of GRB060213
  35. GRB060213: Swift XRT observations and possible afterglow candidate
  36. Konus-Wind observation of bright hard GRB 060213
  37. GRB 060213: IPN localization
  38. GRB060211B: REM optical and NIR observations
  39. GRB 060211A: Further refined analysis of the Swift burst
  40. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  41. GRB 060211b: P60 Observations
  42. GRB 060211B: Swift/BAT refined analysis
  43. GRB060210: Swift/UVOT Upper Limits
  44. GRB 060210: Optical Observations
  45. GRB 060211: ROTSE-III Optical Limits
  46. GRB 060211: Swift detection of a long burst
  47. GRB060210: Optical Observations
  48. GRB060210: Early Optical Observations
  49. GRB 060210: optical evolution
  50. GRB 060210: Swift detection of a burst
  51. GRB060210: Optical afterglow
  52. GRB 060209 : TAROT optical observation
  53. GRB 060203: Swift/UVOT upper limits
  54. GRB 060206: TTT Observations
  55. GRB 060121 : WIDGET Pre-trigger limit
  56. GRB060204a: Swift XRT Source is not GRB Afterglow
  57. Orphan GRB Afterglow candidate
  58. GRB 060206: IR Detection of the Afterglow
  59. GRB 060204A: ROSAT Pointing
  60. GRB 060206: Super-LOTIS observations
  61. GRB060204A: Swift/UVOT observations
  62. GRB060206: SDSS Pre-Burst Observations
  63. GRB 060206: High redshift burst
  64. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  65. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  66. GRB060206: Optical afterglow
  67. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  68. GRB060203: WHT Z-band observations
  69. BAT GRB 060204C is probably not a GRB
  70. GRB060204C: optical observation
  71. GRB 060204A: Swift XRT upper limit
  72. GRB 060204A: FRAM optical observations
  73. GRB060204B: Swift/UVOT refined analysis
  74. GRB 060204C: optical observations
  75. Swift XRT Observation of GRB 060204C
  76. GRB 060204B: Swift-BAT refined analysis
  77. GRB 060204B: ART early limit
  78. GRB 060204b: Keck/LRIS Afterglow Confirmation
  79. GRB 060204C: Liverpool Telescopes optical limit
  80. GRB 060204C: ROTSE-III Optical Limits
  81. GRB 060204C: Swift-BAT detection of a burst
  82. GRB060204B, optical observation
  83. GRB060204B - SDSS pre-burst observations
  84. GRB 060204B: Swift detection of a burst
  85. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  86. GRB 060203: RTT150 optical observations
  87. Swift-BAT trigger is GRB 060203
  88. GRB 060203: IR Counterpart
  89. GRB060203: Observations with SARA
  90. GRB 060203: P60 Confirmation of Optical Afterglow
  91. Possible GRB 060203: optical observations at Asiago
  92. GRB 060202: Gemini-N J, H, K_s observations
  93. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  94. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  95. GRB060202, optical observation
  96. GRB 060202: Swift/UVOT upper limits
  97. GRB 060202: Swift detection of a burst
  98. GRB 060121: Gemini Late-time Observations
  99. GRB 060130: PROMPT Observations
  100. GRB060130: Further R-band imaging

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