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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"

36141 results found.

  1. GRB 110106A: CrAO optical observations
  2. GRB 110119A: Fermi GBM detection
  3. GRB 110120A: Fermi GBM detection
  4. GRB 110119A: Suzaku WAM observation of the prompt emission
  5. GRB 110112A: optical upper limit
  6. GRB 110120A: MASTER optical observations
  7. GRB110119: Swift/UVOT Detection
  8. GRB 110119A: Swift-XRT refined Analysis
  9. GRB110119A: MITSuME Okayama optical upper limits
  10. GRB 110119A: Swift-BAT refined analysis
  11. GRB 110119A: PAIRITEL NIR Afterglow Detection
  12. GRB 110119A: Enhanced Swift-XRT position
  13. GRB 110119A: Swift detection of a burst with an optical detection
  14. GRB110106A, mm-radio observations
  15. GRB 101219B: tentative redshift and spectroscopic supernova detection
  16. GRB 101219B: GROND detection of a SN signature
  17. GRB 101219B: correction
  18. GRB 101219B: Likely the GRB host emission dominates now in the uvw2 filter
  19. New feature in Fermi GBM GRB Ground Position Notices
  20. Swift-BAT Trigger 442539 is not a GRB
  21. Swift Trigger 442539 is probably not a GRB
  22. Short GRB 110112B : early optical limit by "Pi of the Sky"
  23. GRB101225A - timing analysis
  24. GRB 110112B: Fermi GBM observation
  25. The Christmas burst GRB 101225A - optical spectroscopy with GTC
  26. GRB 110112B: Swift XRT and UVOT observations of the INTEGRAL burst
  27. GRB 110112A: MITSuME Akeno and Okayama optical upper limits
  28. GRB 110107A: Swift-XRT afterglow confirmation
  29. GRB 101225A: HST observations - no host detected
  30. GRB 101225A: Redshift retraction and results of additional photometric follow-up at the NOT
  31. GRB 110112B: A short GRB detected by INTEGRAL
  32. GRB 110112A: Swift-XRT refined Analysis
  33. GRB 110112A: Swift/UVOT upper limits
  34. GRB 110112A: WHT candidate afterglow/host galaxy
  35. GRB 110112A: MASTER optical observations
  36. GRB 110112A: Swift-BAT refined analysis
  37. GRB 110112A: Enhanced Swift-XRT position
  38. GRB 110106B: MASTER optical observations
  39. GRB110112A: TNT optical afterglow candidate
  40. GRB 110112A: Swift detection of a possible short burst
  41. GRB 110106B: early optical and near-IR observations
  42. GRB 110107A: Swift/UVOT upper limits
  43. GRB 101225a
  44. GRB 101219b. Possible radio afterglow detection.
  45. GRB 110106B: MASTER early optical observations
  46. GRB 110107A: Swift-XRT Afterglow Candidate
  47. GRB 110107A: Swift-BAT refined analysis
  48. GRB 110107A detected in ground analysis of BAT slew data
  49. GRB 101213A: Gemini-N galaxy redshift
  50. GRB 110106B: Fermi GBM detection
  51. Short GRB 110106A: MASTER OT observations
  52. GRB 110106B: Swift-XRT refined Analysis
  53. GRB 110106B: Gemini-North / WHT detection of a fading afterglow
  54. GRB 110106A: TNG NIR observations
  55. GRB 110106B Gemini-N galaxy redshift
  56. GRB 110106B: Liverpool Telescope observations
  57. GRB 110106A: ISAS-Kanazawa optical upper limit
  58. GRB 110106A: MITSuME Okayama optical upper limits
  59. GRB 110106B: WHT candidate afterglow
  60. GRB 110106B: Swift-BAT refined analysis
  61. GRB 110106B: Enhanced Swift-XRT position
  62. GRB 110106A: Swift/UVOT Upper Limits
  63. GRB 110106A: TNG redshift of the closeby galaxy
  64. GRB 110106A: Swift-XRT refined Analysis
  65. GRB110106B: Xinglong TNT upper limit
  66. GRB 110106A: Swift-BAT refined analysis
  67. GRB 110106A: Enhanced Swift-XRT position
  68. GRB 110106B: Swift detection of a burst
  69. GRB 110106A: TNG optical observations and candidate counterparts
  70. GRB 110106A: MASTER optical observations
  71. GRB 101225A: Keck redshift
  72. GRB110106A: Xinglong TNT upper limit
  73. GRB 110106A: Swift detection of a burst
  74. GRB 101225A: Host galaxy
  75. GRB 101219A: Gemini-North host redshift
  76. GRB 110102A: Swift-XRT refined Analysis
  77. GRB 101219B: After 2 weeks still detected by Swift/UVOT
  78. Konus-Wind observation of GRB 110102A
  79. GRB110102A: Swift/UVOT observations
  80. GRB110102A: MITSuME Okayama Optical Observation
  81. GRB 110102A: Fermi GBM observation
  82. GRB 110102A: Swift-BAT refined analysis
  83. GRB 110102A: Enhanced Swift-XRT position
  84. GRB 110102A: Swift detection of a burst with an optical detection
  85. GRB 101225A: optical break from NOT observation
  86. GRB 101225A: MMT spectroscopy
  87. GRB 101225A: P60 Observations
  88. GRB 101225A: MAXI/GSC observations
  89. GRB 101225A Late-time emission observed by Swift-BAT
  90. GRB 101225: Optical follow-up of the Christmas burst
  91. GRB 101225A: WHT observations
  92. Tentative redshift of GRB101225A (Christmas's burst) from Swift-XRT data
  93. GRB 101225A, Swift-BAT refined analysis
  94. GRB 101225A: Swift/UVOT Detection
  95. GRB 101225A: Swift-XRT refined Analysis
  96. GRB 101225A: Enhanced Swift-XRT position
  97. Trigger 441015 / GRB 101225A: Further NOT optical observation
  98. Trigger 441015 / GRB 101225A: NOT optical afterglow candidate
  99. GRB 101225A (Swift trigger 441015): optical upper limit
  100. Trigger 441015: Swift detection of a possible burst or transient

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