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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. Swift/UVOT observations of GRB071118
  2. GRB 071117: Swift-XRT revised position
  3. Konus-Wind and Konus-A observations of GRB 071117
  4. Swift XRT follow-up observations of GRB071008
  5. Swift/UVOT upper limits for GRB 071117
  6. GRB071118: Swift XRT refined analysis
  7. GRB 071117: Gemini Optical Afterglow Discovery
  8. GRB 071118, Swift-BAT refined analysis
  9. GRB 071117: TAROT La Silla observatory optical observations
  10. GRB 071112B: Gemini Image Differencing
  11. GRB 071118: Swift detection of a burst
  12. GRB 071117: Gemini Observations
  13. GRB 071117: Las Campanas optical observations
  14. GRB 071117: Swift-XRT refined analysis
  15. GRB 071117, Swift-BAT refined analysis
  16. VLT FORS2 observations of short hard GRB071112B
  17. GRB 071117: Swift/XRT position
  18. GRB 071117: Initial Swift/UVOT observations
  19. GRB 071117: Swift detection of a bright burst
  20. Swift detection of MXB 0656-072
  21. VLA radio upper limit on GRB 071112C
  22. ATCA radio observations of short hard burst GRB 071112B
  23. GRB 071112C: Optical and NIR data observed with KANATA
  24. Correction to the Swift-BAT Transient Identification (trigger=296683)
  25. GRB 071112C: WSRT Radio Observations
  26. GRB071112C: Errata of MITSuME Ic band photometry
  27. GRB 071112C: optical observation
  28. GRB 071112C: optical observation
  29. GRB 071112C: emission lines and refined VLT redshift
  30. GRB 071112C MITSuME Akeno early optical observation
  31. GRB 071112C: Gemini Absorption Redshift
  32. GRB 071112B: 2nd epoch of Magellan i-band imaging
  33. GRB 071112C: SARA upper limit
  34. GRB 071112C : Second Epoch Lulin R-band observations
  35. GRB071112C MITSuME Okayama Optical Observation
  36. GRB 071112C: Swift-BAT refined analysis
  37. GRB 071112C: Swift/UVOT observations
  38. GRB 071112C: Swift XRT refined analysis
  39. GRB 071112C: Optical observations at Crni Vrh
  40. Swift UVOT upper limits of GRB071112B
  41. GRB 071112C: VLT redshift
  42. GRB 071112B: Magellan i-band imaging
  43. GRB 071112B: Gemini Optical Imaging (Correction)
  44. GRB 071112B: Gemini Optical Imaging
  45. GRB 071112B: Swift-XRT preliminary analysis
  46. GRB 071112B, Swift-BAT partial refined analysis of the SHB
  47. GRB071112C: NOT observations
  48. GRB 071112C: Palomar Pre-Imaging
  49. Swift-BAT trigger 296491 is not a GRB
  50. GRB 071112C : Lulin R-band observation
  51. GRB 071112C: RTT150 optical observations
  52. GRB 071112C: TAROT Calern observatory optical observations
  53. Swift XRT follow-up observations of GRB071028B
  54. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  55. GRB 071112C: Optical and NIR afterglows observed with KANATA
  56. GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
  57. GRB 071112B: ROTSE-III Rapid Optical Limits
  58. GRB 071112C: Swift detection of a burst with an optical counterpart
  59. GRB 071112B: Swift detection of a short hard burst
  60. GRB 071112: Swift detection of a possible burst
  61. GRB071109: Super-LOTIS observations
  62. VLA IInd observation of INTEGRAL burst GRB 071109
  63. Swift/UVOT initial analysis of GRB071109
  64. GRB 071109: further Swift-XRT analysis
  65. GRB 071109: TAROT Calern observatory optical observations
  66. No radio detection at Swift-XRT position
  67. GRB 071109: Swift-XRT possible X-ray counterpart
  68. VLA prompt radio detection of the INTEGRAL burst 071109
  69. GRB 071109: IBIS refined analysis
  70. GRB 071109: BOOTES-2 prompt optical observations
  71. GRB 071109: A long GRB detected by INTEGRAL
  72. GRB 071104: Swift-XRT Team Refined Analysis
  73. GRB 071104: Possible Swift UVOT Afterglow Candidate
  74. GRB 071104: Swift-XRT position
  75. GRB 071104: Gamma Ray Burst Localization by SuperAGILE
  76. GRB071010b: optical observation
  77. Swift XRT and UVOT observations of GRB071028B
  78. GRB 071101, Swift-BAT refined analysis
  79. GRB 071101: Swift-XRT Team refined analysis
  80. GRB071101: Optical and NIR upper limits by KANATA
  81. GRB0711101: Two new source from Xinglong TNT observation
  82. GRB 071101: TAROT Calern observatory optical observations
  83. GRB 071101: Swift XRT position
  84. GRB071101 LOAO B,V,R,I observation
  85. GRB 071101: BOOTES-2 prompt optical observations
  86. GRB 071101: a nearby galaxy
  87. GRB 071101: Swift detection of a burst
  88. GRB 071031, Swift-BAT refined analysis
  89. GRB 071031: Swift/UVOT detection of afterglow
  90. GRB 071031: Swift-XRT Team refined analysis
  91. GRB 071020: MITSuME Akeno optical observations
  92. GRB 071031: REM NIR and Optical observation
  93. GRB 071031, SMARTS afterglow observations
  94. GRB 071031: VLT high-resolution spectroscopy
  95. GRB071031: Rapid PROMPT Detections
  96. GRB 071031: GROND detection in all bands
  97. GRB 071031: Swift detection of a burst with an optical counterpart
  98. GRB 071028B Swift-BAT detection of a burst
  99. GRB071025: Optical+NIR observations
  100. GRB 071028: SARA observations of variable source

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