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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"

28061 results found.

  1. GRB 070612A: Super-LOTIS observations
  2. GRB 070612A: Rapid Decay
  3. GRB 070612A: Suzaku/WAM observation of the prompt emission
  4. SWIFT J195509.6+261406 / GRB 070610: OPTIMA-Burst observations
  5. GRB070612A: MITSuME Okayama Observation
  6. GRB 070612A: continued SARA observations
  7. GRB 070611: Watcher Observations
  8. Swift Trigger 282176 is Cygnus X-1
  9. GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby
  10. GRB 070612B: SARA upper limit
  11. GRB 070612B, Swift-BAT refined analysis
  12. GRB 070612A, Swift-BAT refined analysis
  13. SWIFT J195509.6+261406 / GRB 070610: SWIFT continued observations
  14. GRB 070612B: Swift/UVOT upper limits
  15. GRB 070612B: FRAM limit
  16. GRB070612B: P60 Observations
  17. GRB 070612A: SARA detection of possible OT
  18. GRB 070610: TAROT Calern observatory optical observations
  19. GRB 070610: MITSuME OAO optical upper limit
  20. GRB070612 - SDSS Pre-Burst Observations
  21. GRB 070612: Swift detection of a burst
  22. GRB 070610: OPTIMA-Burst detection of continued strong flaring activity
  23. GRB 070610: SARA upper limit
  24. GRB 070610: Swift-XRT refined analysis
  25. GRB 070611: Swift/UVOT Observations
  26. GRB 070611: Swift-XRT refined analysis
  27. GRB 070611, Swift-BAT refined analysis
  28. GRB 070610: Optical observations from OSN
  29. GRB 070610: Watcher Observations
  30. GRB 070611: ROTSE-III Detection of Late Rising Optical Counterpart
  31. GRB 070611: ROTSE-III Optical Limits
  32. GRB 070610: Swift-UVOT Upper Limits
  33. GRB 070610: OPTIMA-Burst high-time-resolution optical observations
  34. GRB 070610, Swift-BAT refined analysis
  35. GRB 070412: TAROT Calern observatory optical observations
  36. GRB 070411: TAROT Calern observatory optical observations
  37. GRB070520B: optical observations
  38. GRB070520: optical observation
  39. GRB070518: optical observation
  40. GRB070521: optical observation
  41. GRB 070531: NOT nIR observations
  42. GRB 070531: Swift-BAT refined analysis
  43. GRB 070531: I-band observations from IAC80
  44. GRB 070531: Liverpool Telescope Optical Observations
  45. GRB 070529: SARA upper limit
  46. Swift/UVOT refined analysis of GRB070529
  47. GRB 070529: Optical aterglow from MIRO
  48. GRB 070529: Swift-XRT refined analysis
  49. GRB 070529, Swift-BAT refined analysis
  50. GRB 070529: Xinglong TNT Optical Upper Limit
  51. GRB 070529: Swift detection of a burst with an optical aterglow
  52. GRB 070412: Deep Keck imaging
  53. Swift trigger 280447 is probably a Galactic transient
  54. GRB 070518, deep LBT photometry
  55. Konus-Wind observation of GRB 070521
  56. GRB070521: Second Epoch Gemini Imaging
  57. GRB 070521: Swift/UVOT Upper Limits
  58. GRB 070521, optical observation
  59. GRB 070521: Swift-XRT refined analysis
  60. GRB 070521: Keck imaging
  61. GRB070521: Gemini Observations
  62. GROND upper limits of GRB 070521
  63. GRB 070520B: SARA upper limit
  64. GRB 070520A: SARA upper limit
  65. GRB 070521: SARA upper limit
  66. GRB 070521: Subaru observations and possible host detection
  67. GRB 070520B: Swift/UVOT Upper Limits
  68. GRB 070520A: Subaru Observations
  69. GRB 070521, Swift-BAT refined analysis
  70. GRB 070520A: Swift UVOT Upper Limits
  71. GRB 070520B: Swift-XRT refined analysis
  72. GRB 070521: TAROT La Silla observatory optical observations
  73. GRB070521 - SDSS Pre-Burst Observations
  74. GRB 070521: Swift detection of a burst
  75. GRB 070520A: MITSuME Akeno optical upper limits
  76. GRB 070520B, Swift-BAT refined analysis
  77. GRB 070520A, Swift-BAT refined analysis
  78. GRB 070520A: Swift-XRT refined analysis
  79. GRB 070518: TNG observations
  80. GRB 070520B: Swift detection of a burst
  81. GRB 070520: Xinglong EST optical Upper Limit
  82. GRB 070520: Swift detection of a burst
  83. VLA observation of GRB 070518
  84. GRB 070518: Swift-XRT refined analysis
  85. GRB070518: UVOT refined analysis
  86. GRB 070518, Swift-BAT refined analysis
  87. GRB 070518: OT confirmed form Xinglong TNT observation
  88. GRB 070518: Swift detection of a burst with optical afterglow
  89. GRB070517: Swift-XRT Refined Analysis
  90. GRB 070517, Swift-BAT refined analysis
  91. GRB 070517: Optical search
  92. GRB 070517: Swift detection of a burst
  93. GRB 070509: objects inside XRT error circle
  94. GRB 070512: IPN localization and Konus spectrum of a bright burst
  95. GRB070419A: optical observations
  96. GRB 070509: Swift/UVOT Upper Limits
  97. Konus-Wind and Konus-A observation of GRB 070508
  98. GRB 070510: Swift detection of a possible burst
  99. GRB070509: Swift-XRT Refined Analysis
  100. GRB 070509, Swift-BAT refined analysis

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