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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 070615: A long GRB detected by INTEGRAL
  2. SWIFT J195509.6+261406 (GRB 070610): further observations
  3. GRB 070612A: Super-LOTIS observations
  4. GRB 070612A: Rapid Decay
  5. GRB 070612A: Suzaku/WAM observation of the prompt emission
  6. SWIFT J195509.6+261406 / GRB 070610: OPTIMA-Burst observations
  7. GRB070612A: MITSuME Okayama Observation
  8. GRB 070612A: continued SARA observations
  9. GRB 070612A: spectral lag
  10. GRB 070611: Watcher Observations
  11. Swift Trigger 282176 is Cygnus X-1
  12. GRB 070612A: MDM Observations
  13. GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby
  14. GRB 070612B: SARA upper limit
  15. GRB 070612B, Swift-BAT refined analysis
  16. GRB 070612A, Swift-BAT refined analysis
  17. GRB 070612B: Swift-XRT refined analysis
  18. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
  19. GRB 070612B: Swift/UVOT upper limits
  20. GRB 070612B: FRAM limit
  21. GRB070612B: P60 Observations
  22. GRB 070612B: KAIT limits
  23. GRB 070612A: SARA detection of possible OT
  24. GRB 070612B: Swift XRT position from downlink data
  25. GRB 070610: TAROT Calern observatory optical observations
  26. GRB 070610: MITSuME OAO optical upper limit
  27. GRB 070612B: Swift detection of a burst
  28. GRB070612 - SDSS Pre-Burst Observations
  29. GRB 070612: Swift detection of a burst
  30. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  31. GRB 070610: SARA upper limit
  32. GRB 070610: Swift-XRT refined analysis
  33. GRB 070610: TLS RRM sees flaring behaviour - Galactic transient?
  34. GRB 070611: Swift/UVOT Observations
  35. GRB 070611: Swift-XRT refined analysis
  36. GRB 070611, Swift-BAT refined analysis
  37. GRB 070610: Optical observations from OSN
  38. GRB 070610: Watcher Observations
  39. GRB 070611: VLT redshift
  40. GRB 060121 : pseudo-z = 1.9 ('intermediate-duration' burst)
  41. GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
  42. GRB 070611; Swift-XRT position
  43. GRB 070611: ROTSE-III Optical Limits
  44. GRB 070611: Swift detection of a burst
  45. GRB 070610: Swift-UVOT Upper Limits
  46. GRB 070610: OPTIMA-Burst high-time-resolution optical observations
  47. GRB 070610, Swift-BAT refined analysis
  48. GRB 070610; Swift-XRT position
  49. GRB 070610: Swift detection of a burst
  50. GRB 070412: TAROT Calern observatory optical observations
  51. GRB 070411: TAROT Calern observatory optical observations
  52. GRB 070419A, deep LBT photometry and possible supernova detection
  53. GRB070520B: optical observations
  54. GRB070520: optical observation
  55. GRB070518: optical observation
  56. GRB070521: optical observation
  57. Swift/UVOT refined analysis of GRB070531
  58. GRB 070531: NOT nIR observations
  59. GRB 070531: Swift-BAT refined analysis
  60. GRB 070531: I-band observations from IAC80
  61. GRB 070531: Swift-XRT position
  62. GRB 070531: Liverpool Telescope Optical Observations
  63. GRB 070531: Swift detection of a burst
  64. GRB 070529: SARA upper limit
  65. Swift/UVOT refined analysis of GRB070529
  66. GRB 070529: MARGE Observations
  67. GRB 070529: Optical aterglow from MIRO
  68. GRB 070529: Gemini Redshift
  69. GRB 070529: Swift-XRT refined analysis
  70. GRB 070529, Swift-BAT refined analysis
  71. GRB 070529: Xinglong TNT Optical Upper Limit
  72. GRB 070529: Swift detection of a burst with an optical aterglow
  73. GRB 070412: Deep Keck imaging
  74. Swift Triggers 280447, 280450 and 280451 are invalid
  75. Swift trigger 280447 is probably a Galactic transient
  76. GRB 070518, deep LBT photometry
  77. GRB 070518: MARGE Observations
  78. GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
  79. Konus-Wind observation of GRB 070521
  80. GRB 070518: optical observation
  81. GRB070521: Second Epoch Gemini Imaging
  82. GRB070521: NIR observations
  83. GRB070520B: NIR observations
  84. GRB 070521: Swift/UVOT Upper Limits
  85. GRB 070521, optical observation
  86. GRB 070521: Swift-XRT refined analysis
  87. GRB 070521: Keck imaging
  88. GRB070521: Gemini Observations
  89. GROND upper limits of GRB 070521
  90. GRB 070521 Milagro GeV/TeV Observations
  91. GRB 070520B: SARA upper limit
  92. GRB 070520A: SARA upper limit
  93. GRB 070521: SARA upper limit
  94. GRB 070521: Subaru observations and possible host detection
  95. GRB070518: Optical/NIR observation
  96. GRB 070520B: Swift/UVOT Upper Limits
  97. GRB 070520A: Subaru Observations
  98. GRB 070521, Swift-BAT refined analysis
  99. GRB 070520A: Swift UVOT Upper Limits
  100. GRB 070520B: Swift-XRT refined analysis

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