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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 120118B: RTT150 optical observations
  2. GRB 120119A: SMARTS optical/IR afterglow observations
  3. GRB 120119A: Swift-XRT refined Analysis
  4. GRB 120119A: Enhanced Swift-XRT position
  5. GRB 120102A, the review of the sky area in plate archive
  6. GRB 120119A: Fermi GBM observation
  7. GRB 120118B, Swift-BAT refined analysis
  8. Konus-Wind observation of GRB 120119A
  9. GRB 120119A: optical observations
  10. GRB 120118B: TNG NIR observations
  11. GRB 120118B: Swift-XRT refined Analysis
  12. GRB 120118B : Lulin Optical limit
  13. GRB 120119A: MMT redshift confirmation
  14. GRB 120119A: Lick 3m Spectroscopy
  15. GRB 120119A: Gemini-S redshift
  16. GRB 120119A: PROMPT optical observation of early afterglow
  17. GRB 120119A: GROND Detection of the Optical/NIR Afterglow
  18. GRB 120118B: Swift/UVOT Upper Limits
  19. GRB 120119A: Liverpool Telescope afterglow detection
  20. GRB 120119A: PAIRITEL NIR Detection
  21. GRB 120119A: Swift detection of a burst with an optical counterpart
  22. GRB 120118B: NOT observations
  23. GRB 120118B: Enhanced Swift-XRT position
  24. GRB 120118B: Faulkes Telescope South observations
  25. XRF 120118A: early optical limit by "Pi of the Sky"
  26. GRB 120118B: Swift-XRT position
  27. GRB 120118B: MASTER optical observations
  28. GRB 120118B: Swift detection of a burst
  29. XRF 120118A: Optical candidate
  30. XRF 120118A: further INTEGRAL analysis
  31. XRF 120118A: an X-Ray Flash detected by INTEGRAL
  32. GRB 120116A: Swift/UVOT Upper Limits
  33. GRB 120116A: Swift-XRT refined Analysis
  34. GRB 120116A: Enhanced Swift-XRT position
  35. AXP 4U 1042+61: Mondy optical observations
  36. GRB 120116A: Mondy optical observations
  37. GRB 120116A: Gemini optical/IR candidate
  38. GRB 120116A: EVLA observations
  39. GRB 120116A: WHT optical observations
  40. GRB 120116A: Optical observations at Crni Vrh
  41. GRB 120116A: Swift-BAT refined analysis
  42. GRB 120116A: NOT observations
  43. GRB 120116A: IAC80 I-band observations
  44. GRB 120116A: Bassano Bresciano Observatory optical observations
  45. GRB 120116A: MASTER Early optical limit
  46. GRB 120116A: Swift detection of a burst
  47. GRB 120114A found in ground analysis of BAT data
  48. GRB 111228A: optical observations
  49. AXP 4U 0142+61: Swift-BAT refined analysis (trigger 511611)
  50. GRB 120106A: optical upper limit
  51. Swift detection of an SGR burst from AXP 4U 0142+61
  52. GRB 120107A: Suzaku WAM observation of the prompt emission
  53. GRB 110915B, the review of the sky area in plate archives
  54. GRB 120107A: Fermi GBM observation
  55. GRB 120106A: MITSuME Okayama Optical Observation (update)
  56. Konus-Wind observation of GRB 120107A
  57. IPN Triangulation of GRB 120107A
  58. GBM trigger 347620337 (GRB 120107A?) : High-energy photon emission in Fermi/LAT data
  59. GRB 120106A: Swift/UVOT Upper Limits
  60. GRB 120106A: Bassano Bresciano Observatory optical observations
  61. GRB 120106A: MITSuME Okayama Ks-band upper limit
  62. GRB 120106A: MASTER Early OT marginally detection
  63. GRB 120106A: Swift-XRT refined Analysis
  64. INTEGRAL Weak trigger #6433: GRT Optical Observation
  65. GRB 120106A: Swift-BAT refined analysis
  66. GRB 120106A: MITSuME Okayama Optical upper limits
  67. GRB 120106A: Enhanced Swift-XRT position
  68. GRB 120106A: TAROT Calern observatory optical observations
  69. GRB 120106A: MASTER-Tunka optical observations
  70. GRB 120106A: Swift detection of a burst
  71. GRB111228A :LOAO R-band Observations
  72. GRB 111225A, the review of the sky area in plate archives
  73. GRB 111222A, the review of the sky area in plate archives
  74. GRB 111222A: Fermi GBM observations
  75. GRB 111222A: Second Swift observation
  76. GRB111209A: ATCA detection at 5.5, 9, and 18GHz
  77. GRB111225A: RAPTOR Early Detection of the Optical Counterpart
  78. GRB 111211A: Detection of the SN with the 10.4m GTC
  79. GRB 120102A: Fermi GBM observation
  80. Konus-Wind observation of GRB 120102A
  81. GRB 120102A: Swift-BAT refined analysis
  82. GRB 111228A: optical observations in CrAO
  83. GRB 120102A: Swift-XRT refined Analysis
  84. GRB 120102A: Swift/UVOT Detection
  85. GRB 120102A: Enhanced Swift-XRT position
  86. GRB 120102A: Swift detection of a burst with an optical counterpart
  87. GRB 111225A: optical observations in CrAO
  88. GRB 111228A, optical observations
  89. GRB 111228A: LOAO Optical Observation
  90. Konus-Wind observation of GRB 111228A
  91. GRB 111228A: MASTER-Net optical photometry
  92. GRB 111228A: correction for GCN 12787
  93. GRB 111228A: Optical and NIR observations with Kanata telescope
  94. GRB 110915A, the review of the sky area in plate archives
  95. GRB 111228A: correction to GCN 12784
  96. GRB 111228A: SMARTS optical/IR afterglow observations
  97. GRB 111229A: Swift/UVOT Detection
  98. GRB 111229A: Faulkes Telescope South observations
  99. GRB 111229A: Swift-XRT refined Analysis
  100. GRB 111229A: Enhanced Swift-XRT position

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