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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"

28079 results found.

  1. GRB 070520A: Subaru Observations
  2. GRB 070520A: Swift UVOT Upper Limits
  3. GRB 070520B: Swift-XRT refined analysis
  4. GRB 070521: optical limit by Pi of the Sky
  5. GRB070521: P200 Observations
  6. GRB070521 : Faulkes Telescope North Observations
  7. GRB 070521: TAROT La Silla observatory optical observations
  8. GRB070521: Bright SDSS Galaxy Near XRT Error Circle
  9. GRB 070521: Swift detection of a burst
  10. GRB 070520A: MITSuME Akeno optical upper limits
  11. GRB 070520A: Swift-XRT refined analysis
  12. GRB 070518: TNG observations
  13. GRB 070520B: Swift detection of a burst
  14. GRB 070520: Swift detection of a burst
  15. VLA observation of GRB 070518
  16. GRB 070518: Swift-XRT refined analysis
  17. GRB 070517: Gemini optical imaging
  18. GRB070518: UVOT refined analysis
  19. GRB070518: OSN observation
  20. GRB 070518: Swift detection of a burst with optical afterglow
  21. GRB070517: Swift-XRT Refined Analysis
  22. GRB 070517: Swift detection of a burst
  23. GRB 070509: objects inside XRT error circle
  24. GRB070419A: optical observations
  25. GRB 070419A, Deep LBT photometry
  26. GRB 070509: Swift/UVOT Upper Limits
  27. GRB 070510: Swift detection of a possible burst
  28. GRB070509: Swift-XRT Refined Analysis
  29. GRB 070508: OA fading and tentative redshift
  30. GRB 070509: REM observations
  31. GRB 070509: Swift detection of a burst
  32. GRB 070509: ROTSE-III Optical Limits
  33. GRB070508: Swift/UVOT Observations
  34. GRB 070508, SMARTS optical afterglow observation
  35. GRB 070508: Multicolor optical observations and possible redshift limit
  36. GRB 070508: Swift-XRT refined analysis
  37. GRB 070508: Optical afterglow detection
  38. GRB 070508: REM observations
  39. GRB 070508: Swift detection of an intense burst with an optical counterpart
  40. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  41. GRB070506: Swift/UVOT Observations
  42. GRB070506: Swift XRT refined analysis
  43. GRB 070506: Swift detection of a burst with optical afterglow
  44. GRB 070412, deep LBT imaging
  45. GRB 070429A: Swift XRT further analysis
  46. GRB070429B: VLT observations
  47. GRB 070429A: optical observations
  48. GRB070429B: position correction
  49. GRB 070309: Swift-XRT afterglow confirmation
  50. GRB070429B: possible host galaxy detection
  51. VLA observation of GRB 070429B
  52. Swift/UVOT observations of GRB070429B
  53. Swift/UVOT observations of GRB070429A
  54. GRB 070429A: Swift XRT refined analysis
  55. GRB 070429A: optical and NIR observations
  56. GRB 070429B: Swift XRT refined analysis
  57. GRB 070429B: ROTSE-III Optical Limits
  58. GRB 070429B: Swift detection of a short burst
  59. GRB 070429: ROTSE-III Optical Limits
  60. GRB 070429: Swift detection of a burst
  61. LT monitoring of GRB070412
  62. GRB 070427: Swift detection of a burst
  63. GRB 070411, further deep LBT photometry
  64. GRB 070411: Late-time Keck imaging
  65. GRB 070420, SMARTS optical/IR afterglow observations
  66. GRB 070411, deep LBT photometry
  67. GRB 070411: break in the optical light curve
  68. GRB070419A: Kuiper Optical detection
  69. GRB070419a: Swift UVOT observations
  70. GRB 070420: optical rebrightening observed at Mt. John
  71. GRB 070420: Swift XRT refined analysis
  72. GRB070420: Swift UVOT continuing observations
  73. GBR 070419A: Swift/XRT refined analysis
  74. GRB 070420: TAROT La Silla observatory optical observations
  75. GRB 070420: NIR and optical afterglow confirmed
  76. GRB 070420: Swift detection of a burst with optical afterglow
  77. GRB 070419A: MITSuME Okayama Observations
  78. GRB 070419A: Early Super-LOTIS Observations
  79. GRB 070419A Swift-BAT Refined Analysis
  80. GRB 070419A: RAPTOR Detection of Early Emission
  81. GRB 070419B: Swift XRT refined analysis
  82. GRB 070419: Keck/LRIS Absorption Redshift
  83. GRB 070419B: optical afterglow confirmation
  84. GRB 070419A, Optical observations
  85. GRB 070411: Deep VLT detection
  86. GRB 070419A: SARA observations
  87. GRB 070419A: NAYUTA Optical Observation
  88. GRB 070419B optical afterglow candidate
  89. GRB 070419B: optical afterglow candidate
  90. GRB 070419A: Lulin Optical observation
  91. Infrared detection of GRB070419A with UKIRT
  92. GRB 070419A: Kiso Optical observation
  93. GRB070330: Correction to UVOT position
  94. GRB 070419: P60 Confirmation of Optical Afterglow
  95. GRB 070419B: Swift detection of a burst
  96. GRB 070419 optical afterglow candidate
  97. GRB 070419A: ROTSE-III Optical Limits
  98. GRB 070419: Swift detection of a burst
  99. Trigger 276045: Swift detection of a possible burst
  100. GRB 070406: Swift XRT refined analysis

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