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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"

4046 results found.

  1. GRB 160425A: Swift detection of an unusual burst with an optical afterglow
  2. LIGO/Virgo G211117: LOFAR follow-up
  3. GRB 160325A: GROND Upper Limits
  4. SGR 0755-2933, Swift-BAT refined analysis
  5. Swift detection of a likely new SGR: SGR 0755-2933
  6. LIGO/Virgo G194575: EWE for NOWT follow-up of northern sky
  7. GRB 160314A: Swift detection of a burst
  8. LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
  9. GRB 160228A: GROND Afterglow Candidate
  10. GRB 160220A: MASTER-Amur observations
  11. LIGO/Virgo G184098: Correction for GCN Circular 18361
  12. LIGO/Virgo G211117: LOFAR follow-up
  13. GRB 160206B: iPTF P48 Observations and Optical Transient Candidates
  14. GRB 160131A: Mondy optcial observations
  15. GRB 160131A: MITSuME Ishigakijima Optical Observation
  16. GRB 160131A: Khureltogot optical observations
  17. GRB 160131A: Xinglong 60cm WFT optical observation
  18. GRB 160121A: TSHAO optical afterglow confirmation
  19. GRB 151228B: AbAO optical upper limit
  20. GRB 160117B: GROND optical/NIR afterglow observations
  21. LIGO/Virgo G211117: VISTA imaging
  22. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  23. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  24. LIGO/Virgo G211117: LOFAR follow-up
  25. LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
  26. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  27. LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
  28. LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
  29. GRB 151229A: MITSuME Akeno optical upper limits
  30. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  31. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  32. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  33. GRB 151229A: MITSuME Okayama upper limits
  34. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  35. GRB 151228B: MITSuME Akeno optical upper limits
  36. GRB 151229A: Fermi GBM observation
  37. GRB 151228B: Fermi GBM observation
  38. LIGO/Virgo G211117: Further Swift-XRT sources
  39. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  40. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  41. IBAS Alert 7313 is SGR J1935+2154
  42. GRB 151221A: INTEGRAL detection of a short burst or possible SGR
  43. GRB 151216A: MAXI/GSC detection
  44. GRB 151205C: Optical follow-up observations at Kiso
  45. GRB 130831A: MASTER early OT detection and LC
  46. GRB 151205C: MAXI/GSC detection
  47. Fermi GBM trigger 470712580/151202062 is not a GRB
  48. Swift-BAT refined analysis of trigger 664624 from SGR J1819-1600
  49. Swift-BAT probable detection of an outburst from SGR J1819-1600 (AX J1818.8-1559)
  50. GRB 151120A: Swift-XRT afterglow detection
  51. Swift-BAT trigger 663164 is not a burst.
  52. GRB 151027A: Mondy optical observations
  53. LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
  54. LIGO/Virgo G194575: INAF-TNG follow-up of iPTF15dkm and iPTF15dlj
  55. GRB 151029A: MITSuME Ishigakijima upper limits
  56. GRB 151029A: LCOGT-FTS afterglow observations
  57. LIGO/Virgo G194575: VLA follow-up
  58. GRB 151029A: GROND afterglow observations
  59. GRB 151027A: LCOGT-McDonald afterglow observations
  60. LIGO/Virgo G194575: further Pan-STARRS observations of the RA=1hr localisation region
  61. LIGO/Virgo G194575: Near-infrared follow-up with OAO-WFC
  62. LIGO/Virgo G194575: MAXI/GSC observations
  63. GRB 151021A: Swift detection of a burst
  64. Fermi GBM trigger 466316973/151012187 is not a GRB
  65. Konus-Wind observation of GRB 151001B
  66. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  67. GRB 151001B: Swift detection of a burst
  68. IPN Triangulation of GRB 150922A (short/hard)
  69. LIGO/Virgo G184098: TAROT network optical observations
  70. LIGO/Virgo G184098: Observations from the TOROS collaboration
  71. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  72. GRB 150911A: WHT optical imaging
  73. GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day
  74. GRB 150910A: Swift detection of a burst with an optical afterglow
  75. GRB 150907B: MASTER-SAAO early optical observations
  76. GRB 150906A: Fermi GBM detection
  77. GRB 150902A: Swift-XRT observations
  78. GRB 150831B: MASTER-IAC early optical observations
  79. Fermi GBM trigger 150829183 is not a GRB
  80. Fermi GBM trigger 150828520 is not a GRB
  81. Konus-Wind observation of GRB 150818A
  82. IPN Triangulation of GRB 150819B (short / very intense)
  83. Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
  84. GRB 150728A: TSHAO optical observations
  85. Trigger 650221: Swift detection of a IGR J00291+5934
  86. SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
  87. Trigger 649113: Swift detection of SGR 1E 1841-045
  88. Swift-XRT observations of GRB 150710A
  89. Fermi Gamma-ray Burst Monitor trigger bn150629779 is not a GRB
  90. GRB 150627A: Swift/UVOT Detection
  91. GRB 150627A: Swift-XRT afterglow detection
  92. V404 Cyg: MASTER Swift, Integral alert observations
  93. GRB 150622A: MAXI/GSC detection
  94. GRB 150608A: MAXI/GSC detection
  95. GRB 150530A: Swift detection of a burst
  96. GRB 150523A: Suzaku WAM observation of the prompt emission
  97. Konus-Wind observation of GRB 150523A
  98. GRB 150523A: Fermi-LAT detection
  99. GRB 150523A: Fermi GBM detection
  100. GRB 150424A: 9.8 GHz VLA detection

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