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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"

28055 results found.

  1. GRB 111016A: P60 Afterglow Candidate
  2. GRB 111016A: Swift-XRT refined Analysis
  3. GRB 111016A: Enhanced Swift-XRT position
  4. GRB 111016A: Swift-XRT observations
  5. GRB 111016A: Swift detection of a burst
  6. GRB 110921A: optical observations
  7. GRB 111008A: Swift/UVOT Upper Limits
  8. GRB 111008A: IAC80 I-band observations
  9. GRB 111008A: Swift-XRT refined Analysis
  10. GRB 111008A, GROND observations
  11. GRB 111008A: NOT optical observation
  12. GRB 111008A: Gemini optical counterpart
  13. GRB 111008A: Enhanced Swift-XRT position
  14. GRB 111008A, Swift-BAT refined analysis,
  15. GRB 111008A: Swift detection of a burst
  16. GRB 111005A: ATCA 18 GHz detection
  17. GRB 111005A: ATCA radio upper limit
  18. GRB 111005A : miniTAO/ANIR NIR observations
  19. GRB 111005A: GROND NIR observations
  20. GRB 111005A: VLT IR observations
  21. GRB 111005A: Swift-BAT refined analysis
  22. GRB 111005A: Swift detection of a burst
  23. GRB 111003A: Fermi GBM detection
  24. GRB 110921A: MITSuME-Akeno Optical photometry
  25. Skynet/Dolomiti observations of GRB 110928A
  26. Skynet observations of GRB 110928A
  27. GRB 110928A: RAPTOR Limits During Gamma-ray Emitting Interval
  28. GRB 110928A: Swift/UVOT Upper Limits
  29. GRB 110928A: Swift-XRT refined Analysis
  30. GRB 110825A: GROND Observations
  31. GRB 110928A: Enhanced Swift-XRT position
  32. GRB 110928A: P60 Observations
  33. GRB 110928A: Further PAIRITEL NIR Observations
  34. GRB 110928A: Swift-BAT refined analysis
  35. GRB 110928A: Swift-XRT observations
  36. GRB 110928A: Swift/UVOT finding chart observation
  37. GRB 110928A: PAIRITEL NIR Observations
  38. GRB 110928A: ROTSE-III Optical Limits
  39. GRB 110924A: Swift detection of a possible burst
  40. GCN for GRB 110921B
  41. GRB 110921A: Swift/UVOT Observations
  42. GRB 110921A: NOT observations
  43. GRB 110921A: Fermi GBM observation
  44. GRB 110921A: TNT astrometry
  45. GRB 110921A: Swift-XRT refined Analysis
  46. GRB 110921A, Swift-BAT refined analysis
  47. GRB 110921A: optical observations in Mt. Terskol and Maidanak observatories
  48. GRB 110921A: Enhanced Swift-XRT position
  49. GRB 110918A: Swift-XRT refined Analysis
  50. GRB 110921A: Swift detection of a burst
  51. GRB 110915B : X-ray afterglow confirmation
  52. GRB 110918A: Swift/UVOT Detection of the Optical Counterpart
  53. GRB 110918A optical observation
  54. GRB 110918A: GROND detection of the afterglow candidate
  55. GRB 110918A: INT optical detection of Swift candidate afterglow
  56. GRB 110918A: Swift-XRT observations
  57. GRB110918A: BOOTES-1 optical limit
  58. Swift detection of short bursts from PSR J1647-4552
  59. GRB 110915A: Konus-Wind and Swift/BAT joint spectral analysis
  60. GRB 110915B: GROND Observations of the Optical/NIR Afterglow Candidate
  61. GRB 110915A: Swift/UVOT Upper Limits
  62. GRB 110915B: Swift/UVOT Upper Limits
  63. GRB 110915A: GROND Upper limits
  64. GRB 110915A, Swift-BAT refined analysis
  65. GRB 110915A: Swift-XRT refined Analysis
  66. GRB 110915B: Afterglow candidate from OSN
  67. GRB 110915A: Deep Near-IR Limits from Magellan
  68. GRB 110915B: XRT afterglow candidate
  69. GRB 110903A: Suzaku WAM observation of the prompt emission
  70. GRB 110915A: Deep Gemini-South i/z-band imaging
  71. GRB110915A MITSuME Okayama J-band upper-limit
  72. GRB 110915A: MITSuME Okayama and Ishigakijima Optical upper limits
  73. GRB 110915A: NOT observations
  74. GRB 110915A: 1.23m CAHA I-band observations
  75. GRB 110915B: SuperAGILE localization of a long GRB
  76. GRB 110915A: Enhanced Swift-XRT position
  77. GRB 110915A: GMG optical upper limit
  78. GRB 110915A: MASTER-Net early limit
  79. GRB 110915A: Swift detection of a burst
  80. GRB 110825A: Further Swift/XRT Observations
  81. GRB 110731A: SAO RAS and Terskol observations
  82. GRB 110906A(?): Burst detection (unconfirmed) from Swift-BAT slew data
  83. GRB 110905A: Potential BAT trigger on MAXI J1836-194
  84. GRB 110903A: Swift/UVOT Upper Limits
  85. GRB 110903A: Swift-XRT observations
  86. GRB 110820A: optical upper limit
  87. SGR Swift J1834.9-0846: Correction to the Swift-BAT refined spectral analysis
  88. Trigger 502024: Swift detection of KS 1741-293
  89. GRB110825A: Fermi GBM observation
  90. SGR Swift J1834.9-0846: Swift-BAT refined analysis of trigger 501752
  91. Swift detection of an SGR burst from Swift J1834.9-0846
  92. GRB 110825A: Suzaku WAM observation of the prompt emission
  93. GRB 110825A: GMG optical observation
  94. GRB 110827A, Swift-BAT refined analysis
  95. GRB 110825A: optical afterglow candidate
  96. GRB 110825A: field inspection and possible host galaxy
  97. GRB110825A: Swift target of opportunity observation
  98. IPN triangulation of GRB110825A (very intense, long-duration)
  99. GRB 110820A, the review of the sky area in plate archives
  100. Swift-BAT Trigger 501485 is noise

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