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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"

8480 results found.

  1. GRB 160303A: Swift detection of a burst, possibly short
  2. GRB 160228A: Swift/UVOT Upper Limits
  3. GRB 160228A: Mondy optcial observations
  4. GRB 160228A: RATIR Optical and NIR Observations
  5. GRB 160228A: GROND Afterglow Candidate
  6. GRB 160228A: Swift detection of a burst
  7. GRB 160227A: Swift detection of a burst with an optical counterpart
  8. GRB 160225A: LOAO optical upper limit
  9. GRB 160225A: Continued RATIR Optical and NIR Observations
  10. GRB 160225A: RATIR Optical and NIR Observations
  11. GRB 160225A: Swift detection of a burst
  12. GRB 160223A: Swift-XRT afterglow detection
  13. GRB 160223A: AbAO optical observations
  14. GRB 160223B: LCOGT-FTN optical observations
  15. GRB 160223B: Swift ToO observations
  16. GRB 160221A: Swift ToO observations
  17. GRB 160216A: Swift detection of a burst
  18. GRB 160206B: Fermi GBM detection
  19. Swift Trigger 672897 is probably not an astrophysical event
  20. GRB 160206B: iPTF P48 Observations and Optical Transient Candidates
  21. GRB 160206A: Tiled Swift observations
  22. GRB 160203A: GROND Afterglow Candidate
  23. GRB 160203A: Swift detection of a burst
  24. Konus-Wind observation of GRB 160131A
  25. GRB 160131A: Swift detection of a burst with an optical counterpart
  26. GRB 160127A: TAROT La Silla observatory optical light curve
  27. GRB 160127A: Swift detection of a burst with an optical counterpart
  28. GRB 160123A: Swift detection of a burst
  29. GRB 160121A: Swift detection of a burst
  30. GRB 160119A: afterglow confirmation from the NOT
  31. GRB 160119A: NOT and GTC afterglow candidate
  32. GRB 160117B: Early iTelescope observation
  33. GRB 160119A: Swift detection of a burst
  34. LIGO/Virgo G211117: Refined localization from CBC parameter estimation
  35. GRB 160117B: Swift detection of a burst with optical counterpart
  36. IPN Triangulation of GRB 160113A
  37. GRB 151225A: Correction to the trigger time of GCN 18724
  38. GRB 160113A: Swift-XRT observations
  39. GRB 160113A: Swift ToO observations
  40. GRB 160113A: iPTF P48 Observations and Optical Transient Candidates
  41. LIGO/Virgo G184098: Refined localizations from CBC parameter estimation
  42. LIGO/Virgo G211117: iPTF Observations of PS15dpn
  43. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  44. LIGO/Virgo G211117: INAF TNG follow-up of Kanata telescope candidate
  45. GRB 160104A: LCOGT-FTN afterglow candidate
  46. GRB 160104A: Swift detection of a burst
  47. LIGO/Virgo G211117: Fermi/LAT observations
  48. LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
  49. GRB 160102A: Tiled Swift observations
  50. GRB 160101A: Tiled Swift observations
  51. LIGO/Virgo G211117: FLOYDS Classification of SMTJ13331687-1607330 as a Two-Week-Old Type Ia Supernova
  52. LIGO/Virgo G211117: LBT follow-up imaging of iPTF15fhq
  53. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  54. LIGO/Virgo G211117: LBT Follow-up of iPTF15fen
  55. Trigger 668879: Swift detection of V 404 Cyg again
  56. Trigger 668877: Swift detection of V 404 Cyg
  57. LIGO/Virgo G211117: SkyMapper observations and transient candidate
  58. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  59. GRB 151228B: Swift-BAT refined analysis
  60. GRB 151229A: Swift detection of a short burst
  61. LIGO/Virgo G211117: Fermi GBM Observations
  62. GRB 151228B: Swift detection of a burst with an optical detection
  63. LIGO/Virgo G211117: Identification of a GW CBC Candidate
  64. LIGO/Virgo G184098: Fermi-LAT search for high-energy gamma-ray counterpart
  65. GRB151215A: P60 Optical Afterglow Candidate
  66. GRB 151215A: Swift detection of a burst
  67. GRB 151212A: GROND Optical Afterglow Candidate
  68. GRB 151212A: Tiled Swift observations
  69. GRB 151210A: Optical afterglow candidate from LCOGT-Cerro Tololo
  70. GRB 151210A: Swift detection of a burst
  71. GRB 151205C: Tiled Swift observations
  72. GRB151205B: Initial UVOT observations
  73. GRB 151205A: Swift detection of a burst
  74. GRB 151127A: Swift detection of a short burst
  75. GRB 151122A: Swift ToO observations
  76. Swift Trigger 664610: is unlikely a GRB
  77. LIGO/Virgo G194575: Updated significance from offline GW analysis
  78. GRB 151120A: Swift ToO observations
  79. LIGO/Virgo G194575: Fermi GBM Observations
  80. GRB 151118A: Swift detection of a burst
  81. GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
  82. GRB 151114A: Swift detection of a burst with an optical counterpart
  83. GRB 151112A: GROND Detection of the Optical/NIR Afterglow Candidate
  84. GRB 151112A: initial UVOT observations
  85. GRB 151111A: GROND marginal detection of a afterglow candidate
  86. GRB 151111A: Fermi GBM observation
  87. GRB 151111A: LCOGT-FTS afterglow observations
  88. GRB 151111A: Swift detection of a burst
  89. LIGO/Virgo G194575: INAF-Asiago Telescope further analysis of iPTF candidates
  90. LIGO/Virgo G194575: MAXI/GSC further analysis
  91. LIGO/Virgo G194575: LT Spectroscopy of iPTF-15dmk
  92. GRB 151031A: Swift detection of a burst
  93. GRB 151029A: Swift detection of a burst with an optical counterpart
  94. GRB 151027B: NOT optical afterglow candidate
  95. LIGO/Virgo G194575 : RATIR Observation of La Silla - QUEST Candidate
  96. GRB 151027B: Swift detection of its 1000-th burst
  97. LIGO/Virgo G194575: iPTF Optical Transient Candidates
  98. GRB 151027A: Swift detection of a burst with a bright optical afterglow
  99. LIGO/Virgo G194575: MAXI/GSC observations
  100. Possible Fermi-LAT Gamma-ray counterpart for LIGO/Virgo G194575

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