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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"
  1. GRB 110315A: Swift-XRT refined Analysis
  2. GRB 110315A: Swift-BAT refined analysis
  3. GRB 110315A: Enhanced Swift-XRT position
  4. GRB 110315A: MASTER early optical observations
  5. GRB 110315A: Swift detection of a burst
  6. GRB110312A: MITSuME Okayama Optical upper limits
  7. GRB 110312A: RTT150 optical observations
  8. GRB 110312A: Swift/UVOT Upper Limits
  9. GRB 110312A: Swift-XRT refined Analysis
  10. GRB 110312A: GROND Upper Limits
  11. GRB 110312A: Enhanced Swift-XRT position
  12. GRB 110312A: Swift-BAT refined analysis
  13. GRB 110312A: Swift detection of a burst
  14. GRB 110305A: REM detection of a possible NIR afterglow
  15. GRB110305A: MITSuME Ishigakijima Optical upper limits
  16. GRB 110305A: Swift/UVOT Upper Limits
  17. GRB 110305A: Swift-XRT refined Analysis
  18. GRB 110305A: Enhanced Swift-XRT position
  19. GRB 110305A: Swift-BAT refined analysis
  20. IBAS trigger n. 6138 is not a GRB
  21. GRB 110305A: GROND Detection of Optical Afterglow
  22. GRB 110305A: Swift detection of a burst
  23. GRB 110223A: optical upper limits
  24. GRB 110301A: Fermi GBM detection
  25. GRB101225A: early EVLA Observations of Christmas Burst
  26. Swift/UVOT observations of GRB110223A
  27. No IPN GRB detected in conjunction with candidate GRB 110215
  28. GRB GRB 110223A: MASTER VWF early optical observations
  29. IBAS distribution of coordinates for low significance INTEGRAL GRB triggers
  30. Swift/UVOT observations of GRB110223b
  31. GRB 110223A: Swift-BAT refined analysis
  32. GRB 110223A : early optical limit by "Pi of the Sky"
  33. GRB 110223A: Liverpool Telescope observations
  34. GRB 110223A: Swift-XRT refined Analysis
  35. GRB 110223B: Swift-XRT refined Analysis
  36. GRB 110223A: Enhanced Swift-XRT position
  37. GRB 110223B: Enhanced Swift-XRT position
  38. GRB 110223B: Swift-BAT refined analysis
  39. GRB 110223B: GROND Detection of Optical Afterglow Candidate
  40. GRB 110223A: Observations from BOOTES-2
  41. GRB 110223B: Swift detection of a burst
  42. GRB 110223A: Swift detection of a burst
  43. GRB 101225A, the review of the sky area in plate archives
  44. OT 110215: Further NIR observations from NOT of the GRB candidate
  45. GRB 110213B: Swift/UVOT observations
  46. GRB110213B: X-ray afterglow confirmation
  47. Fermi GBM detection of an SGR-like burst
  48. Swift XRT and UVOT Observations of OT 110215
  49. OT 110215: NIR observations from NOT of GRB candidate
  50. GRB 110213A: optical observations in CrAO
  51. GRB 110213B: GROND observations of the optical/NIR afterglow
  52. GRB 110213A: optical observations in Mondy
  53. Fermi GBM trigger 319534757 (110216319) is not a GRB
  54. GRB110205A: EVLA Observations
  55. OT 110215: possible GRB from 2MASS J00264184+8324093
  56. Swift/UVOT observations of GRB110210a.
  57. GRB 110210A: optical upper limit
  58. GRB 110213B: Gemini South Redshift
  59. GRB 110213B: Possible Host Galaxy in SDSS Stripe 82 Imaging
  60. GRB 110210A: ROVOR Upper Limit
  61. GRB 110213A: YNAO-GMG Observations
  62. GRB 110213B: P60 Optical Afterglow Candidate
  63. GRB 110213A: TNT optical observations
  64. GRB110213A: RAPTOR Early Optical Peak and Plateau Measurements
  65. GRB 110212A: Swift XRT and UVOT observations
  66. Swift GRB110213A: interesting behaviour
  67. GRB 110213A: Fermi GBM observation
  68. GRB 110205A: Konkoly optical observations
  69. GRB 110213B: Swift XRT observation
  70. GRB 110213A: MITSuME Akeno Optical Observation
  71. Konus-Wind observation of GRB 110213A
  72. Konus-Wind observation of GRB 110213B
  73. GRB 110213A: Swift-XRT refined Analysis
  74. GRB 110213B: MAXI/GSC refined analysis
  75. GRB110213A: MITSuME Okayama Optical Observation
  76. GRB 110213A: Swift/UVOT refined analysis
  77. GRB 110213A: THO optical observations
  78. GRB 110213B: MAXI/GSC detection of a probable GRB
  79. GRB 110213A: Lightbuckets Optical Observations
  80. GRB 110213A, Swift-BAT refined analysis
  81. GRB 110213A: optical observations
  82. GRB 110213A: Enhanced Swift-XRT position
  83. GRB110212A: MITSuME Okayama optical upper limits
  84. GRB 110213A: KAIT observations
  85. GRB 110213A: GRAS011 optical observations
  86. GRB 110213A: Bok Telescope Redshift
  87. GRB 110213A: ROTSE-III Detection of Optical Counterpart
  88. GRB 110213A: P60 Optical Afterglow Detection
  89. GRB 110213A: Swift detection of a burst with optical afterglow
  90. GRB 110212A: GRT Optical Observation
  91. GRB 110212A, Swift-BAT refined analysis
  92. GRB 110212A: SARA-N Optical Limits
  93. GRB110212A: BOOTES-2/TELMA optical limits
  94. GRB 110212A: ROTSE-III Optical Limits
  95. GRB 110212A: Swift detection of a burst
  96. GRB 110201A: Subaru/MOIRCS Ks-band photometry
  97. Konus-Wind observation of GRB 110205A (correction to GCN 11659)
  98. GRB 110205A: detection of optical linear polarization from CAHA
  99. GRB 110207A: Suzaku WAM observation of the prompt emission
  100. GRB 110210A: optical upper limit

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