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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

43720 results found.

  1. LIGO/Virgo G211117: FLOYDS Classification of SMTJ13331687-1607330 as a Two-Week-Old Type Ia Supernova
  2. LIGO/Virgo G211117: LBT follow-up imaging of iPTF15fhq
  3. GRB 151231B: Fermi GBM observation
  4. GRB 151231A: Fermi GBM observation
  5. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  6. Trigger 668949: Swift detection of V 404 Cyg
  7. LIGO/Virgo G211117: MAXI/GSC observations
  8. MASTER-NET observations of V404Cyg Swift Trigger 668877
  9. LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
  10. Konus-Wind observation of GRB 151227B
  11. LIGO/Virgo G211117: VLA follow-up
  12. LIGO/Virgo G211117: LBT Follow-up of iPTF15fen
  13. Trigger 668879: Swift detection of V 404 Cyg again
  14. Trigger 668877: Swift detection of V 404 Cyg
  15. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  16. LIGO/Virgo G211117: INAF TNG follow-up of MASTER OT J020906.21+013800.1
  17. LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
  18. IPN Triangulation of GRB 151227B
  19. GRB 151228A: Correction to GCN 18770
  20. LIGO/Virgo G211117: SkyMapper observations and transient candidate
  21. GRB 151228A: Swift-XRT refined Analysis
  22. V404Cyg Swift Trigger 668097: CrAO RT-22 radio observations
  23. LIGO/Virgo G211117: MASTER Observations of the 3 iPTF candidates
  24. V404Cyg Swift Trigger 668097: AbAO optical observations
  25. GRB 151228B: Swift/UVOT Detection
  26. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  27. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  28. GRB 151229A Swift-BAT Spectral lag analysis
  29. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  30. GRB 151228B: MITSuME Akeno optical upper limits
  31. GRB 151229A: Swift-XRT refined Analysis
  32. GRB 151229A: Fermi GBM observation
  33. GRB 151228B: Fermi GBM observation
  34. GRB 151228A: Swift-BAT refined analysis
  35. GRB 151228B: Swift-BAT refined analysis
  36. GRB 151229A: Swift-BAT refined analysis
  37. GRB 151229A: Enhanced Swift-XRT position
  38. GRB 151228B: Swift-XRT refined Analysis
  39. LIGO/Virgo G211117: Further Swift-XRT sources
  40. GRB 151228A: T60 observations
  41. GRB 151229A: Swift detection of a short burst
  42. LIGO/Virgo G211117: DESGW program observations with DECam
  43. GRB 151228B: Enhanced Swift-XRT position
  44. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  45. LIGO/Virgo G211117: Fermi GBM Observations
  46. GRB 151228B: Swift detection of a burst with an optical detection
  47. LIGO/Virgo G211117: MASTER Observations and Inspection + OT
  48. LIGO/Virgo G211117: INTEGRAL was inactive at the time of the event
  49. GRB 151228A: Fermi GBM observation
  50. LIGO/Virgo G211117: Pan-STARRS1 observations 2015-12-28
  51. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  52. LIGO/Virgo G211117: Further Swift-XRT sources
  53. LIGO/Virgo G211117: Swift-XRT sources
  54. GRB 151228A: Swift detection of a short burst
  55. LIGO/Virgo G211117: SWASP optical observations
  56. LIGO/Virgo G211117: Identification of a GW CBC Candidate
  57. GRB 151227B: Fermi GBM detection
  58. GRB 151227A: Fermi GBM detection
  59. GRB 151212A iTelescope observation
  60. GRB 151225A: CALET Gamma-Ray Burst Monitor detection of a possible short GRB
  61. Konus-Wind observation of GRB 151222A
  62. Fermi GBM trigger 472694170/151224997 is not a GRB
  63. V404Cyg Swift Trigger 668097: TSHAO optical observations
  64. IPN Triangulation of GRB 151222A (short/hard)
  65. Fermi GBM trigger 151221730 is not a GRB
  66. Trigger 668097: Swift detection of V 404 Cyg
  67. GRB 151222A: Fermi GBM detection
  68. Fermi GBM trigger 151221690 is not a GRB
  69. Fermi GBM trigger 472271765/151220108 is not a GRB
  70. GRB 151221A: INTEGRAL detection of a short burst or possible SGR
  71. Fermi GBM trigger 472166503/151218890 is not a GRB
  72. LIGO/Virgo G184098: Fermi-LAT search for high-energy gamma-ray counterpart
  73. GRB 151215A: TSHAO optical observations
  74. GRB151215A: Continued P60 Observations
  75. GRB 151212B: CALET Gamma-Ray Burst Monitor detection
  76. GRB 151216A: MAXI/GSC detection
  77. GRB 151210B: Fermi GBM observation
  78. GRB151215A: Early optical light curve from pt5m, La Palma
  79. GRB 151210B: CALET Gamma-Ray Burst Monitor detection
  80. GRB 151215A: Swift-XRT refined Analysis
  81. GRB 151215A: Swift-BAT refined analysis
  82. GRB 151215A: MASTER early OT detection and light curve
  83. GRB 151215A: NOT spectroscopy and redshift
  84. GRB 151215A: Enhanced Swift-XRT position
  85. GRB 151215A: GROND Detection of the Optical/NIR Afterglow
  86. GRB 151215A: Prompt enhanced Swift-XRT position
  87. GRB151215A: P60 Optical Afterglow Candidate
  88. GRB 151215A: Swift detection of a burst
  89. LIGO/Virgo G184098: LOFAR follow-up
  90. GRB 151212A: GROND Optical Afterglow Candidate
  91. GRB 151212A: Swift-XRT afterglow detection
  92. GRB 151212A: Tiled Swift observations
  93. GRB 151212A: MAXI/GSC detection
  94. GRB 151210A: Swift/UVOT Upper Limits
  95. GRB 151210A: Swift-BAT refined analysis
  96. GRB 151210A: Swift-XRT refined Analysis
  97. GRB 151210A: Enhanced Swift-XRT position
  98. GRB 151210A: GROND Afterglow Confirmation
  99. GRB 151210A: Optical afterglow candidate from LCOGT-Cerro Tololo
  100. GRB 151210A: Swift detection of a burst

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