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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"

37423 results found.

  1. GRB 071118: P60 Observations
  2. GRB071118 MITSuME OAO optical observation
  3. GRB 071118: Observations from OSN
  4. GRB 071117: VLT observations and probable redshift
  5. Swift/UVOT observations of GRB071118
  6. GRB 071117: Swift-XRT revised position
  7. Konus-Wind and Konus-A observations of GRB 071117
  8. Swift XRT follow-up observations of GRB071008
  9. Swift/UVOT upper limits for GRB 071117
  10. GRB071118: Swift XRT refined analysis
  11. GRB 071117: Gemini Optical Afterglow Discovery
  12. GRB 071118, Swift-BAT refined analysis
  13. GRB 071112B: Gemini Image Differencing
  14. GRB 071118: Swift detection of a burst
  15. GRB 071117: Gemini Observations
  16. GRB 071117: Las Campanas optical observations
  17. GRB 071117: Swift-XRT refined analysis
  18. VLT FORS2 observations of short hard GRB071112B
  19. GRB 071117: Swift/XRT position
  20. GRB 071117: Initial Swift/UVOT observations
  21. GRB 071117: Swift detection of a bright burst
  22. Swift detection of MXB 0656-072
  23. VLA radio upper limit on GRB 071112C
  24. ATCA radio observations of short hard burst GRB 071112B
  25. GRB 071112C: Optical and NIR data observed with KANATA
  26. Correction to the Swift-BAT Transient Identification (trigger=296683)
  27. GRB 071112C: WSRT Radio Observations
  28. GRB071112C: Errata of MITSuME Ic band photometry
  29. GRB 071112C: optical observation
  30. GRB 071112C: optical observation
  31. GRB 071112C: emission lines and refined VLT redshift
  32. GRB 071112C MITSuME Akeno early optical observation
  33. GRB 071112C: Gemini Absorption Redshift
  34. GRB 071112B: 2nd epoch of Magellan i-band imaging
  35. GRB 071112C: SARA upper limit
  36. GRB 071112C : Second Epoch Lulin R-band observations
  37. GRB071112C MITSuME Okayama Optical Observation
  38. GRB 071112C: Swift-BAT refined analysis
  39. GRB 071112C: Swift/UVOT observations
  40. GRB 071112C: Swift XRT refined analysis
  41. GRB 071112C: Optical observations at Crni Vrh
  42. Swift UVOT upper limits of GRB071112B
  43. GRB 071112C: VLT redshift
  44. GRB 071112B: Magellan i-band imaging
  45. GRB 071112B: Gemini Optical Imaging (Correction)
  46. GRB 071112B: Gemini Optical Imaging
  47. GRB 071112B: Swift-XRT preliminary analysis
  48. GRB071112C: NOT observations
  49. Swift-BAT trigger 296491 is not a GRB
  50. GRB 071112C : Lulin R-band observation
  51. Swift XRT follow-up observations of GRB071028B
  52. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  53. GRB 071112C: Optical and NIR afterglows observed with KANATA
  54. GRB 071112C: ROTSE-III Confirmation of Optical Counterpart
  55. GRB 071112B: ROTSE-III Rapid Optical Limits
  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. GRB071109: Super-LOTIS observations
  60. VLA IInd observation of INTEGRAL burst GRB 071109
  61. Swift/UVOT initial analysis of GRB071109
  62. GRB 071109: further Swift-XRT analysis
  63. No radio detection at Swift-XRT position
  64. GRB 071109: Swift-XRT possible X-ray counterpart
  65. VLA prompt radio detection of the INTEGRAL burst 071109
  66. GRB 071109: IBIS refined analysis
  67. GRB 071109: BOOTES-2 prompt optical observations
  68. GRB 071109: A long GRB detected by INTEGRAL
  69. GRB 071104: Swift-XRT Team Refined Analysis
  70. GRB 071104: Possible Swift UVOT Afterglow Candidate
  71. GRB 071104: Gamma Ray Burst Localization by SuperAGILE
  72. GRB071010b: optical observation
  73. Swift XRT and UVOT observations of GRB071028B
  74. GRB 071101: Swift-XRT Team refined analysis
  75. GRB071101: Optical and NIR upper limits by KANATA
  76. GRB0711101: Two new source from Xinglong TNT observation
  77. GRB 071101: Swift XRT position
  78. GRB071101 LOAO B,V,R,I observation
  79. GRB 071101: BOOTES-2 prompt optical observations
  80. GRB 071101: Swift detection of a burst
  81. GRB 071031: Swift/UVOT detection of afterglow
  82. GRB 071031: Swift-XRT Team refined analysis
  83. GRB 071020: MITSuME Akeno optical observations
  84. GRB 071031: REM NIR and Optical observation
  85. GRB 071031, SMARTS afterglow observations
  86. GRB 071031: VLT high-resolution spectroscopy
  87. GRB 071031: Swift detection of a burst with an optical counterpart
  88. GRB 071028B Swift-BAT detection of a burst
  89. GRB 071028: SARA observations of variable source
  90. Swift UVOT upper limits to GRB071028
  91. GRB071028: Xinglong EST V-band upper limit
  92. GRB 071028: Swift-XRT Team refined analysis
  93. GRB 071028: Swift detection of a burst
  94. GRB 071025: Kuiper Telescope Optical Observations
  95. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  96. GRB 071018: Revised BAT position
  97. GRB071021: MARGE Optical Limits
  98. GRB071020, optical upper limit
  99. GRB 071025: SARA VRI upper limits
  100. GRB 071025 Milagro GeV/TeV Observations

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