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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"

28043 results found.

  1. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  2. GRB 071227: Suzaku WAM observation of the prompt emission
  3. GRB 071227: optical afterglow
  4. Further Swift-BAT analysis of GRB 071227
  5. Konus-Wind observation of GRB 071227
  6. GRB 071227: Swift-XRT refined analysis
  7. GRB 071227: VLT probable redshift of the candidate host galaxy
  8. GRB071227: Swift/UVOT refined analysis
  9. GRB 071227: REM NIR and Optical observations
  10. Swift-BAT refined analysis of short GRB 071227
  11. GRB 071227: Swift detection of a burst
  12. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  13. GRB 071125: Suzaku WAM observation of the prompt emission
  14. GRB 070429B: Probable host galaxy and redshift
  15. GRB 071129, Swift-BAT refined analysis
  16. GRB 071126: Enhanced Swift-XRT position
  17. GRB071122: Swift/UVOT Observations
  18. GRB071104: NIR Afterglow Candidate at TNG
  19. GRB 071122, Swift-BAT refined analysis
  20. GRB 071122 Swift-XRT refined analysis
  21. GRB 071122: P60 Optical Afterglow Candidate
  22. GRB 071122: Swift detection of a burst
  23. GRB 071118: P60 Observations
  24. GRB071118 MITSuME OAO optical observation
  25. GRB 071118: Observations from OSN
  26. GRB 071117: VLT observations and probable redshift
  27. Swift/UVOT observations of GRB071118
  28. Konus-Wind and Konus-A observations of GRB 071117
  29. Swift XRT follow-up observations of GRB071008
  30. Swift/UVOT upper limits for GRB 071117
  31. GRB071118: Swift XRT refined analysis
  32. GRB 071117: Gemini Optical Afterglow Discovery
  33. GRB 071118, Swift-BAT refined analysis
  34. GRB 071117: TAROT La Silla observatory optical observations
  35. GRB 071118: Swift detection of a burst
  36. GRB 071117: Gemini Observations
  37. GRB 071117: Swift-XRT refined analysis
  38. GRB 071117, Swift-BAT refined analysis
  39. Swift detection of MXB 0656-072
  40. GRB 071112C: Optical and NIR data observed with KANATA
  41. GRB 071112C MITSuME Akeno early optical observation
  42. GRB 071112C: SARA upper limit
  43. GRB 071112C : Second Epoch Lulin R-band observations
  44. GRB071112C MITSuME Okayama Optical Observation
  45. GRB 071112C: Swift-BAT refined analysis
  46. GRB 071112C: Swift XRT refined analysis
  47. Swift UVOT upper limits of GRB071112B
  48. GRB 071112B: Gemini Optical Imaging
  49. GRB 071112B: Swift-XRT preliminary analysis
  50. GRB 071112B, Swift-BAT partial refined analysis of the SHB
  51. GRB 071112C : Lulin R-band observation
  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: Swift detection of a burst with an optical counterpart
  57. GRB 071112B: Swift detection of a short hard burst
  58. GRB 071112: Swift detection of a possible burst
  59. Swift/UVOT initial analysis of GRB071109
  60. GRB 071109: further Swift-XRT analysis
  61. GRB 071109: TAROT Calern observatory optical observations
  62. GRB 071109: Swift-XRT possible X-ray counterpart
  63. GRB 071109: IBIS refined analysis
  64. GRB 071104: Swift-XRT Team Refined Analysis
  65. GRB 071104: Possible Swift UVOT Afterglow Candidate
  66. GRB 071104: Swift-XRT position
  67. GRB 071104: Gamma Ray Burst Localization by SuperAGILE
  68. Swift XRT and UVOT observations of GRB071028B
  69. GRB 071101, Swift-BAT refined analysis
  70. GRB 071101: Swift-XRT Team refined analysis
  71. GRB071101: Optical and NIR upper limits by KANATA
  72. GRB0711101: Two new source from Xinglong TNT observation
  73. GRB 071101: TAROT Calern observatory optical observations
  74. GRB071101 LOAO B,V,R,I observation
  75. GRB 071101: Swift detection of a burst
  76. GRB 071031, Swift-BAT refined analysis
  77. GRB 071031: Swift-XRT Team refined analysis
  78. GRB 071020: MITSuME Akeno optical observations
  79. GRB 071031: REM NIR and Optical observation
  80. GRB 071031: Swift detection of a burst with an optical counterpart
  81. GRB 071028B Swift-BAT detection of a burst
  82. GRB 071028: SARA observations of variable source
  83. Swift UVOT upper limits to GRB071028
  84. GRB071028: Xinglong EST V-band upper limit
  85. GRB 071028: Swift-XRT Team refined analysis
  86. GRB 071028, Swift-BAT refined analysis
  87. GRB 071028: Swift detection of a burst
  88. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  89. GRB071021: MARGE Optical Limits
  90. GRB071020, optical upper limit
  91. GRB 071025: SARA VRI upper limits
  92. Swift UVOT upper limits
  93. GRB071025: Xinglong TNT I-band upper limit
  94. GRB 071025: Swift-XRT Team refined analysis
  95. GRB 060602A: host redshift
  96. GRB 071025, Swift-BAT refined analysis
  97. GRB071021 : CFHT Ks-band observation
  98. GRB 071025: ROTSE-III Refined Analysis
  99. GRB 071025a: PAIRITEL observations
  100. GRB 071025: ROTSE-III Detection of Optical Counterpart

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