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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"

20960 results found.

  1. GRB 160327A: RATIR Optical and NIR Afterglow Detection
  2. GRB 160325A: GROND Upper Limits
  3. GRB 160325A: Further Swift/UVOT Observations
  4. GRB 160325A: afterglow confirmation
  5. LIGO/Virgo G211117: CALET GBM Observations
  6. GRB160325A: REM NIR observations
  7. Swift detects GX 301-2 in very high state
  8. GRB 160321A: AbAO optical observations
  9. GRB 160321A: Swift/UVOT Upper Limits
  10. GRB 160321A: MASTER observations zero Galaxy latitude GRB
  11. GRB 160310A: Terskol 2-m observations
  12. GRB 160131A: 15 GHz upper limits from AMI-LA
  13. GRB 160314A: Continued RATIR Optical and NIR Observations
  14. GRB 160314A: GROND optical/NIR observations
  15. GRB 160314A: ISON-Ussuriysk optical upper limit, updated photometry and correction of GCN 19184
  16. GRB 160314A: RATIR Optical and NIR Observations
  17. GRB 160314A: Mondy optical observations
  18. GRB 160313A: Swift/UVOT Upper Limits
  19. GRB 160314A: VLT/X-shooter redshift
  20. GRB 160314A: NOT afterglow observations
  21. GRB 160314A: Optical observations from OSN
  22. GRB 160314A: Swift/UVOT Detection
  23. GRB 160228A: GROND afterglow confirmation and X-shooter host candidate redshift
  24. GRB 160314A: Weihai optical upper limit
  25. GRB 160313A: Chante-Perdrix Observatory optical observations
  26. GRB 160313A: MASTER-Net optical observations
  27. GRB 160313A: LT observations
  28. GRB 160313A: TAROT Calern observatory optical observations
  29. GRB 160313A: RATIR Optical and NIR Observations
  30. GRB 160313A: SAO RAS observations
  31. GRB 160310A: MASTER-Kislovods observations
  32. GRB 160310A: Further NOT observations
  33. GRB 160310A: Swift/UVOT Upper Limits
  34. GRB 160310A: RATIR Optical and NIR Observations
  35. GRB 160310A: NOT optical observations
  36. GRB 160310A: LCOGT-SAAO optical upper limits
  37. GRB 160310A: Swift-XRT observations
  38. GRB 160310A: Swift ToO observations
  39. GRB 160303A: X-shooter spectroscopy
  40. Swift trigger 677890 is noise
  41. GRB 160303A: Continued optical monitoring from NOT
  42. GRB 160303A: JCMT SCUBA-2 sub-mm observation
  43. GRB160303A: further GROND observations
  44. GRB 160303A: 9.8 GHz VLA upper limit
  45. GRB 160303A: MMT Optical Detection
  46. GRB 160303A: Continued RATIR Optical and NIR Observations
  47. LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
  48. GRB 160303A: GROND Optical Detection
  49. GRB 160303A: Observations from T150 OSN
  50. GRB 160303A: Optical observations from the NOT
  51. GRB 160303A: Swift/UVOT Detection
  52. GRB 160303A: RAPTOR Observations During Gamma-Ray Emitting Interval
  53. GRB 160303A: LCOGT-FTN optical observations
  54. GRB 160228A: Swift/UVOT Upper Limits
  55. GRB 160227A: Swift/UVOT Detection
  56. GRB 160228A: Mondy optcial observations
  57. GRB 160228A: RATIR Optical and NIR Observations
  58. GRB 160228A: MASTER-Amur prompt observations
  59. GRB 160227A: MASTER prompt OT Detection and LC
  60. GRB 160228A: GROND Afterglow Candidate
  61. GRB 160228A: optical observations
  62. GRB 160227A: NOT redshift
  63. GRB 160225A: TSHAO optical afterglow detection
  64. GRB 160225.81/FERMI Trigg 478121069: MASTER OT J095503.19-355149.4 follow up observations
  65. GRB 160225A: Continued RATIR Optical and NIR Observations
  66. GRB 160225.81/FERMI Trigg 478121069: MASTER OT J095503.19-355149.4 detection
  67. GRB 160225A: MASTER-Amur observations
  68. GRB 160225A: RATIR Optical and NIR Observations
  69. GRB 160225A: Swift/UVOT Upper Limits
  70. GRB 160225A: NOT optical observations
  71. GRB 160225A: WHT LIRIS observations
  72. GRB 160223A: RATIR Optical and NIR Observations
  73. GRB 160225A: MASTER-Amur early observations
  74. GRB 160223A: Swift-XRT afterglow detection
  75. GRB 160221A: Swift-XRT afterglow detection
  76. GRB 160223A: AbAO optical observations
  77. GRB 160223B: MASTER-Amur early observations
  78. GRB 160223B: Khureltogot optical observations
  79. GRB 160223B: Swift-XRT observations
  80. GRB 160223B: LCOGT-FTN optical observations
  81. GRB 160223B: Swift ToO observations
  82. GRB 160223A: GROND optical/NIR afterglow
  83. LVC GW 150914: TAROT/TZAC Final analysis correction
  84. GRB 160221A: GROND upper limits
  85. Correction to the title of Swift GCN 19051
  86. GRB 160220B: Further GROND Observations
  87. Further Swift/UVOT observations of GRB 160220B
  88. GRB 160221A: Swift-XRT observations
  89. GRB 160221A: MASTER-SAAO early observations
  90. GRB 160221A: Swift ToO observations
  91. GRB 160220B: GROND Observations
  92. GRB 160220A: nIR observations at AAT
  93. GRB160220B: Swift/UVOT observations
  94. LIGO/Virgo GW150914
  95. GRB160220A: Swift/UVOT observations
  96. Swift Trigger 674752 is likely a noise fluctuation in the direction of IGR17488-3253
  97. GRB 160220A: TAROT Calern and TAROT La Silla observatory optical observations
  98. GRB 160220A: MASTER-Amur observations
  99. GRB 160220A: GROND Optical/NIR Upper Limits
  100. GRB 160220A: Swift-XRT observations

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