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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"

3050 results found.

  1. GRB 120728A: Swift-XRT refined Analysis
  2. GRB 120728A: GROND observations
  3. GRB 120724A: Swift-XRT refined Analysis
  4. GRB 120709A: Swift re-observation of the field of the X-ray counterpart candidate.
  5. GRB 120722A: Swift-XRT refined Analysis
  6. GRB 120716A: Swift-XRT detection
  7. GRB 120714B: Swift-XRT refined Analysis
  8. GRB 120714A: GROND upper limits
  9. GRB 120714B: GROND confirmation of fading afterglow
  10. GRB 120714A: Swift-XRT refined Analysis
  11. GRB 120712A: Swift-XRT refined Analysis
  12. GRB 120711B: Swift-XRT refined Analysis
  13. GRB 120709A: Swift/UVOT Observations
  14. GRB 120711A: Fermi LAT detection
  15. GRB 120711A: Swift-XRT observations
  16. GRB 120709A: Swift-XRT observations
  17. GRB 120703A: Swift-XRT refined Analysis
  18. GRB 120701A: Swift-XRT afterglow detection and analysis
  19. GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis
  20. GRB120624B: Chandra observations and afterglow detection
  21. GRB 120624B Further Swift-XRT analysis
  22. GRB 120624B: Swift-XRT observations
  23. GRB 120624B: Fermi-LAT Detection
  24. GRB 120612A: Swift-XRT refined Analysis
  25. GRB 120521C: Swift-XRT refined Analysis
  26. GRB 120521B: GROND Upper limits
  27. GRB 120521A: Swift-XRT refined Analysis
  28. GRB 120521C: PAIRITEL NIR Upper Limits
  29. GRB 120521B: Swift-XRT refined Analysis
  30. GRB 120514A: Swift-XRT refined Analysis
  31. GRB 120510A: Swift XRT and UVOT observations
  32. GRB 120422A: VLT/X-shooter spectroscopy of the GRB counterpart
  33. GRB 120422A: Swift-XRT refined Analysis
  34. GRB 120419A: Swift-XRT and UVOT observations
  35. GRB 120403B: Swift-XRT refined Analysis
  36. GRB 120404A: Swift-XRT refined Analysis
  37. GRB 120403B: AAT nIR observations
  38. GRB 120401A: Swift-XRT refined Analysis
  39. The Swift-XRT source associated with trigger 518853 is a cosmic ray
  40. GRB 120328A: Swift-XRT refined Analysis
  41. GRB 120326A: PAIRITEL NIR Observations
  42. GRB 120327A: Swift-XRT refined Analysis
  43. GRB 120326A: Swift-XRT refined Analysis
  44. GRB 120324A: Swift-XRT refined Analysis
  45. GRB 120320A: Swift-XRT refined Analysis
  46. GRB 120302A: Swift XRT refined analysis
  47. GRB 120312A: Swift-XRT refined Analysis
  48. GRB 120311B: Swift-XRT refined Analysis
  49. GRB 120311A: Swift-XRT refined Analysis
  50. GRB 120308A: Further PAIRITEL NIR Observations
  51. GRB 120308A: Swift-XRT refined Analysis
  52. GRB 120308A: PAIRITEL NIR observations
  53. GRB 120305A: Swift-XRT refined Analysis
  54. GRB 111222A: Swift observation on 2012 February 06/07
  55. GRB 120226A: Fermi-LAT detection of a burst
  56. GRB 120224A: Swift-XRT refined Analysis
  57. GRB 120219A: Swift-XRT refined Analysis
  58. GRB 120215A: Swift-XRT refined Analysis
  59. GRB 120213A: Swift-XRT refined Analysis
  60. GRB 120212A: Swift-XRT refined Analysis
  61. GRB 120212A: Errata of subject in GCNC 12936
  62. GRB 120211A: MITSuME Okayama Ks-band Observation
  63. GRB 120211A: Swift-XRT refined Analysis
  64. GRB 120211A: MITSuME Okayama Ks-band upper limit
  65. Swift detection of a burst from LS I +61 303
  66. GRB 120202A: Swift/XRT and UVOT observations
  67. GRB 120121A: Swift-XRT refined Analysis
  68. GRB 120119A: Swift-XRT refined Analysis
  69. GRB 120118B: Swift-XRT refined Analysis
  70. GRB 120119A: PAIRITEL NIR Detection
  71. GRB 120116A: Swift-XRT refined Analysis
  72. GRB 120106A: MITSuME Okayama Ks-band upper limit
  73. GRB 120106A: Swift-XRT refined Analysis
  74. GRB 111222A: Second Swift observation
  75. GRB 120102A: Swift-XRT refined Analysis
  76. GRB 111228A: correction for GCN 12787
  77. GRB 111228A: Optical and NIR observations with Kanata telescope
  78. GRB 111229A: Swift-XRT refined Analysis
  79. GRB 111225A: Lightbuckets Optical Observations
  80. GRB 111228A: Swift-XRT refined Analysis
  81. GRB 111228A: PAIRITEL NIR Detection
  82. XMM-Newton observation of the short GRB 111020A
  83. GRB 111225A: PAIRITEL NIR Upper Limits
  84. GRB 111225A: Swift-XRT refined Analysis
  85. GRB 111222A: Swift/UVOT Observations
  86. GRB 111222A: Swift-XRT observations
  87. GRB 111215B: Swift-XRT observations
  88. GRB 111205A: Confirmation of X-ray Afterglow
  89. GRB 111215A: TNG K-band observations
  90. GRB 111215A: Swift-XRT refined Analysis
  91. GRB 111211A: Swift/UVOT Detection
  92. GRB 111212A: Swift-XRT refined Analysis
  93. GRB 111211A: Swift/XRT target of opportunity observation
  94. GRB 111210A: Swift-XRT refined Analysis
  95. GRB 111208A: Swift-XRT refined analysis
  96. GRB 111208A: Lightbuckets Optical Observations
  97. GRB 111209A: Swift-XRT refined Analysis
  98. GRB 111209A: Swift UVOT refined analysis
  99. GRB 111209A: Swift Burst of Interest
  100. GRB111209A : planned XMM-Newton observation

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