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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"

28047 results found.

  1. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  2. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  3. XRF 080109 in NGC2770: Detectable Superluminal Motion
  4. Refined Swift-XRT analysis of the transient in NGC 2770
  5. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  6. GRB 071227: Suzaku WAM observation of the prompt emission
  7. GRB 071227: optical afterglow
  8. Further Swift-BAT analysis of GRB 071227
  9. Konus-Wind observation of GRB 071227
  10. GRB 071227: Swift-XRT refined analysis
  11. GRB 071227: VLT probable redshift of the candidate host galaxy
  12. GRB071227: Swift/UVOT refined analysis
  13. GRB 071227: REM NIR and Optical observations
  14. Swift-BAT refined analysis of short GRB 071227
  15. GRB 071227: Swift detection of a burst
  16. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  17. GRB 071125: Suzaku WAM observation of the prompt emission
  18. GRB 070429B: Probable host galaxy and redshift
  19. GRB 071129, Swift-BAT refined analysis
  20. GRB 071126: Enhanced Swift-XRT position
  21. GRB071122: Swift/UVOT Observations
  22. GRB071104: NIR Afterglow Candidate at TNG
  23. GRB 071122, Swift-BAT refined analysis
  24. GRB 071122 Swift-XRT refined analysis
  25. GRB 071122: P60 Optical Afterglow Candidate
  26. GRB 071122: Swift detection of a burst
  27. GRB 071118: P60 Observations
  28. GRB071118 MITSuME OAO optical observation
  29. GRB 071118: Observations from OSN
  30. GRB 071117: VLT observations and probable redshift
  31. Swift/UVOT observations of GRB071118
  32. Konus-Wind and Konus-A observations of GRB 071117
  33. Swift XRT follow-up observations of GRB071008
  34. Swift/UVOT upper limits for GRB 071117
  35. GRB071118: Swift XRT refined analysis
  36. GRB 071117: Gemini Optical Afterglow Discovery
  37. GRB 071118, Swift-BAT refined analysis
  38. GRB 071117: TAROT La Silla observatory optical observations
  39. GRB 071118: Swift detection of a burst
  40. GRB 071117: Gemini Observations
  41. GRB 071117: Swift-XRT refined analysis
  42. GRB 071117, Swift-BAT refined analysis
  43. Swift detection of MXB 0656-072
  44. GRB 071112C: Optical and NIR data observed with KANATA
  45. GRB 071112C MITSuME Akeno early optical observation
  46. GRB 071112C: SARA upper limit
  47. GRB 071112C : Second Epoch Lulin R-band observations
  48. GRB071112C MITSuME Okayama Optical Observation
  49. GRB 071112C: Swift-BAT refined analysis
  50. GRB 071112C: Swift XRT refined analysis
  51. Swift UVOT upper limits of GRB071112B
  52. GRB 071112B: Gemini Optical Imaging
  53. GRB 071112B: Swift-XRT preliminary analysis
  54. GRB 071112B, Swift-BAT partial refined analysis of the SHB
  55. GRB 071112C : Lulin R-band observation
  56. GRB 071112C: TAROT Calern observatory optical observations
  57. Swift XRT follow-up observations of GRB071028B
  58. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  59. GRB 071112C: Optical and NIR afterglows observed with KANATA
  60. GRB 071112C: Swift detection of a burst with an optical counterpart
  61. GRB 071112B: Swift detection of a short hard burst
  62. GRB 071112: Swift detection of a possible burst
  63. Swift/UVOT initial analysis of GRB071109
  64. GRB 071109: further Swift-XRT analysis
  65. GRB 071109: TAROT Calern observatory optical observations
  66. GRB 071109: Swift-XRT possible X-ray counterpart
  67. GRB 071109: IBIS refined analysis
  68. GRB 071104: Swift-XRT Team Refined Analysis
  69. GRB 071104: Possible Swift UVOT Afterglow Candidate
  70. GRB 071104: Swift-XRT position
  71. GRB 071104: Gamma Ray Burst Localization by SuperAGILE
  72. Swift XRT and UVOT observations of GRB071028B
  73. GRB 071101, Swift-BAT refined analysis
  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: TAROT Calern observatory optical observations
  78. GRB071101 LOAO B,V,R,I observation
  79. GRB 071101: Swift detection of a burst
  80. GRB 071031, Swift-BAT refined analysis
  81. GRB 071031: Swift-XRT Team refined analysis
  82. GRB 071020: MITSuME Akeno optical observations
  83. GRB 071031: REM NIR and Optical observation
  84. GRB 071031: Swift detection of a burst with an optical counterpart
  85. GRB 071028B Swift-BAT detection of a burst
  86. GRB 071028: SARA observations of variable source
  87. Swift UVOT upper limits to GRB071028
  88. GRB071028: Xinglong EST V-band upper limit
  89. GRB 071028: Swift-XRT Team refined analysis
  90. GRB 071028, Swift-BAT refined analysis
  91. GRB 071028: Swift detection of a burst
  92. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  93. GRB071021: MARGE Optical Limits
  94. GRB071020, optical upper limit
  95. GRB 071025: SARA VRI upper limits
  96. Swift UVOT upper limits
  97. GRB071025: Xinglong TNT I-band upper limit
  98. GRB 071025: Swift-XRT Team refined analysis
  99. GRB 060602A: host redshift
  100. GRB 071025, Swift-BAT refined analysis

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