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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"

41703 results found.

  1. GRB 150818A: Mondy optical observations
  2. GRB150819A: NOT imaging
  3. Konus-Wind observation of GRB 150819B
  4. GRB 150818A: Continued NOT monitoring - afterglow confirmation
  5. GRB 150819B: Fermi GBM detection
  6. GRB 150818A: 10.4m GTC spectroscopy and host galaxy
  7. IPN Triangulation of GRB 150819B (short / very intense)
  8. GRB 150818A: Mondy optical observations
  9. GRB 150818A: MITSuME Ishigakijima upper limits
  10. GRB 150819A: RATIR Optical Observations
  11. GRB 150819A: Swift-XRT refined Analysis
  12. GRB 150818A: MITSuME Akeno optical upper limits
  13. GRB 150819A: Swift-BAT refined analysis
  14. GRB 150819A: MASTER-IAC early upper limit
  15. GRB 150819A: Swift/UVOT Upper Limits
  16. GRB 150818A: Swift-XRT update, correction to GCN 18162
  17. GRB150818A: NOT imaging
  18. GRB 150819A: Swift detection of a burst
  19. GRB 150818A: Swift-XRT refined Analysis
  20. GRB 150818A: Swift/UVOT Detection
  21. GRB 150817A: AAO optical observations
  22. GRB 150817A: LCOGT observations
  23. GRB 150818A: Swift-BAT refined analysis
  24. GRB 150817A: Continued RATIR Optical Observations - Afterglow Confirmation
  25. GRB 150818A: Swift/UVOT candidate afterglow
  26. GRB 150818A: Planned XMM-Newton observation
  27. GRB 150817A: P60 Observations
  28. GRB 150818A: Swift detection of a burst
  29. MASTER OT inside bright ESO240-010 galaxy detection during FERMI trigger GRB150816.83 inspection
  30. GRB 150817A: Swift/UVOT Upper Limits
  31. GRB 150817A: Fermi GBM observation
  32. GRB 150817A: Swift-BAT refined analysis
  33. GRB 150817A: Swift-XRT refined Analysis
  34. GRB 150817A: Continued RATIR Observations, Revised Candidate
  35. GRB 150817A: RATIR Optical Afterglow Candidate
  36. GRB 150817A: Swift detection of a burst
  37. Fermi GBM Trigger 150815694 is not a GRB
  38. GRB 150811A: Continued RATIR Observations
  39. GRB 150811A: Continued RATIR Observations
  40. GBM Trigger 150813665 is not a GRB
  41. Swift Trigger 652046 is a particle shower event
  42. Konus-Wind observation of GRB 150811B
  43. Swift Trigger 652046 is probably not a GRB
  44. GRB 150811A: KAIT Refined Analysis
  45. GRB 150811A: VLA Detection
  46. IPN Triangulation of GRB 150811B
  47. GRB 150811A: Continued RATIR Observations
  48. GRB 150811A: Swift/UVOT further observations
  49. GRB 150811B: Fermi GBM detection
  50. GRB 150811A: Swift-BAT refined analysis
  51. GRB 150811A: SAO RAS optical observations
  52. GRB 150811A: Swift-XRT refined Analysis
  53. GRB 150810A: Fermi GBM detection
  54. GRB 150811A: P60 Observations
  55. GRB 150811A: LCOGT-McDonald afterglow detection
  56. GRB 150811A: Swift/UVOT Detection
  57. GRB 150811A: KAIT optical candidate
  58. GRB 150811A: RATIR Optical Afterglow Detection
  59. GRB 150811A: Swift detection of a burst
  60. Fermi GBM GRB Trigger 460608875: iPTF P48 Observations
  61. Fermi GBM trigger 150807969 is not a GRB
  62. Fermi GBM trigger 150806450 is not a GRB
  63. GRB 150728A: TNG optical observations
  64. Fermi GBM trigger 150805556 is not a GRB
  65. GRB 150727A: IRSF NIR observation
  66. GRB 150801A: Swift-XRT observations
  67. GRB 150801B: Swift/UVOT Upper Limits
  68. GRB 150801B: Swift-BAT refined analysis
  69. GRB 150801B: Swift-XRT refined Analysis
  70. Fermi GBM triggers 150730606 150731173 and 150801590 are not due to GRBs
  71. Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
  72. GRB 150721A (Fermi GBM Trigger 459150552): iPTF P48 Observations
  73. GRB 150801B: Swift detection of a burst
  74. GRB 150801A: Tiled Swift observations
  75. GRB 150801A: MAXI/GSC detection
  76. GRB 150724B: Swift-XRT afterglow detection
  77. GRB 150424A: HST imaging
  78. GRB150724B: Retraction of the uvot detection
  79. GRB 150728A: Continued RATIR Optical Observations
  80. GRB 150728A: TSHAO optical observations
  81. GRB 150728A: RATIR Optical Observations
  82. GRB 150727A: Continued RATIR Optical Observations - Fading
  83. GRB 150728A: AAO optical observations
  84. GRB 150728A: Swift-XRT refined Analysis
  85. GRB 150728A: Swift/UVOT Upper Limits
  86. GRB 150728A: Swift-BAT refined analysis
  87. GRB 150728A: FTN observations
  88. GRB 150727A: RATIR Optical Observations
  89. GRB 150728A: Swift detection of a GRB
  90. GRB 150727A: Swift-BAT refined analysis
  91. GRB 150727A: Watcher optical upper limit
  92. GRB 150727A: Swift/UVOT Detection
  93. GRB 150727A: LCOGT-Cerro Tololo observations
  94. GRB 150727A: Swift-XRT refined Analysis
  95. GRB 150727A: Fermi GBM detection
  96. GRB 150727A: VLT/X-shooter redshift
  97. GRB 150724B: Continued RATIR Optical Observations
  98. GRB 150724B: MASTER upper limit
  99. GRB 150727A: Swift detection of a burst with an optical counterpart
  100. GRB 150724B: Swift/UVOT Detection

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