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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"

16158 results found.

  1. GRB 071025A: RAPTOR Observations of Complex Early Optical Behavior
  2. GRB071021: MARGE Optical Limits
  3. GRB071020, optical upper limit
  4. GRB071025: Optical Pre-imaging from Palomar
  5. GRB 071025: Swift-XRT Team refined analysis
  6. GRB 071025: ROTSE-III Refined Analysis
  7. GRB 071025: Swift XRT refined position
  8. GRB 071025: ROTSE-III Detection of Optical Counterpart
  9. GRB 071021: R-band detection and analysis
  10. GRB 071020: BTA spectroscopy
  11. GRB071021: Optical+NIR observations
  12. Optical observations of GRB 071020
  13. GRB 071021: (Relatively shallow) IR non-detections; motivation for optical spectroscopy
  14. GRB071010b: optical observation
  15. GRB071021: MITSuME Okayama Optical Upper Limits
  16. GRB 071010B: Fading quickly
  17. GRB 071021: optical and NIR observations
  18. GRB 071021: possible high-z burst
  19. GRB071018: 2nd epoch obsevations of Xinglong TNT
  20. GRB 071021: retraction of Faulkes Telescope South candidate
  21. GRB 071021: Swift-XRT Team refined analysis
  22. GRB 071021: Xinglong TNT optical Upper Limit
  23. GRB 071021 : Lulin R-band limit
  24. GRB 071021: Faulkes Telescope South optical candidate
  25. GRB 071010B: Independent Confirmation of Break
  26. GRB071020A: Xinglong TNT Optical afterglow observations
  27. GRB 071020A: IR Imaging with PAIRITEL
  28. GRB 071020: VLT spectroscopy
  29. GRB 071020: ROTSE-III Analysis of Optical Counterpart
  30. GRB 071020A: ROTSE-III Detection of Optical Counterpart
  31. GRB 071018: Mercator Telescope optical observations
  32. GRB071010b: optical observations
  33. GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break
  34. GRB 071013: TNT optical data refined analysis
  35. GRB071013: optical observations
  36. GRB 071010B: Optical observations of EST
  37. GRB 071011: MITSuME Optical Observations
  38. GRB 070920A: deep optical observations at the NOT
  39. GRB 071010B: Photometry after 1.6 days
  40. GRB 071010B: Keck/LRIS Photometry
  41. GRB 071013: Optical observations
  42. GRB 071013: optical observations at NOT
  43. GRB071013: optical limit
  44. GRB071010B, BVRcIc field calibration
  45. GRB 20071013: Xinglong TNT optical Upper Limit
  46. GRB 071011: Optical Limit after 13.95hrs
  47. GRB 071011: Xinglong TNT Optical afterglow observations
  48. GRB 071010B correction to GCN 6892 optical observations
  49. GRB 071011: Swift-XRT refined analysis
  50. VLA non-detection of GRB 071010A
  51. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  52. GRB 071011, Optical afterglow
  53. GRB 071011: Confirmation of P60 optical afterglow
  54. GRB 071010B: Optical Detection
  55. GRB 071011: Kanazawa Optical limits
  56. GRB 071011: P60 Optical Afterglow Candidate
  57. GRB 071011: MARGE Optical Limits
  58. GRB 071010B optical photometry
  59. GRB 071011: XRT afterglow detection
  60. GRB 071010B: Gemini Spectroscopic Observations
  61. GRB 071011: NAYUTA Optical Observation
  62. GRB 071010A: Continued Keck Imaging
  63. GRB 071011: Optical afterglow candidate
  64. Optical Observation: GRB 071010
  65. Optical observations: GRB 071010A
  66. GRB071010B: Swift/XRT detection
  67. GRB 071010A: bright NIR afterglow
  68. GRB071008: optical observations
  69. GRB 071010B possible optical transient
  70. GRB 071010: Swift-XRT observation
  71. GRB 071010 REM NIR observations
  72. GRB 071003: XRT refined analysis
  73. Radio detection of GRB 071003 with the VLA
  74. GRB 071003: VLT spectroscopy
  75. GRB 071003: Keck spectroscopy
  76. GRB 071003: Possible rebrightening
  77. GRB 071003 : Lulin R-band observations
  78. GRB 071003: Swift XRT position
  79. GRB 071003: OA power-law decay indices from KAIT
  80. GRB 071003 Optical observations
  81. GRB 071003: P60 Confirmation of Optical Afterglow
  82. GRB 071003: KAIT optical afterglow observations
  83. GRB 070911, SMARTS optical/IR afterglow observations
  84. GRB 070920B: ROTSE-III Early Optical Limits
  85. GRB 070920B: TAROT La Silla observatory optical observations
  86. INTEGRAL ToO observations of SGR1806-20
  87. GRB 070920b, SMARTS optical observation
  88. GRB 070917: Confirmation of the X-ray afterglow
  89. GRB 070920b: LCO optical observations
  90. GRB 070920B: NOT optical observations
  91. GRB 070920: TAROT Calern observatory optical observations
  92. GRB070917: Confirmation of optical afterglow
  93. GRB920925C: search for host galaxy
  94. GRB070917: optical observations
  95. GRB 070917: P60 Observations
  96. GRB 070917: KAIT optical limits
  97. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  98. GRB 070913: Afterglow candidate detected by TAROT La Silla observatory
  99. GRB 070913: SMARTS optical/IR observations
  100. GRB 070913: TAROT La Silla observatory optical observations

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