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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"

3850 results found.

  1. LIGO/Virgo G211117: Astrosat CZTI upper limits
  2. GRB 160506A: Swift detection of a burst
  3. MASTER search for counterpart to the IceCube event 67093193 (run 127853)
  4. GRB 160425A: SMARTS optical/IR observations
  5. GRB 160425A: Swift detection of an unusual burst with an optical afterglow
  6. LIGO/Virgo G211117: LOFAR follow-up
  7. GRB 160325A: GROND Upper Limits
  8. SGR 0755-2933, Swift-BAT refined analysis
  9. Swift detection of a likely new SGR: SGR 0755-2933
  10. LIGO/Virgo G194575: EWE for NOWT follow-up of northern sky
  11. GRB 160314A: Swift detection of a burst
  12. LIGO/Virgo G211117: GRAWITA LBT follow-up of PS15dpn
  13. GRB 160228A: GROND Afterglow Candidate
  14. GRB 160220A: MASTER-Amur observations
  15. LIGO/Virgo G184098: Correction for GCN Circular 18361
  16. LIGO/Virgo G211117: LOFAR follow-up
  17. GRB 160206B: iPTF P48 Observations and Optical Transient Candidates
  18. GRB 160131A: Mondy optcial observations
  19. GRB 160131A: MITSuME Ishigakijima Optical Observation
  20. GRB 160131A: Khureltogot optical observations
  21. GRB 160131A: Xinglong 60cm WFT optical observation
  22. GRB 160121A: TSHAO optical afterglow confirmation
  23. GRB 151228B: AbAO optical upper limit
  24. GRB 160117B: GROND optical/NIR afterglow observations
  25. LIGO/Virgo G211117: VISTA imaging
  26. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  27. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  28. LIGO/Virgo G211117: LOFAR follow-up
  29. LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
  30. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  31. LIGO/Virgo G211117: Liverpool Telescope followup of EM candidates
  32. LIGO/Virgo G211117: OAO-WFC NIR follow-up observations
  33. GRB 151229A: MITSuME Akeno optical upper limits
  34. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  35. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  36. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  37. GRB 151229A: MITSuME Okayama upper limits
  38. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  39. GRB 151228B: MITSuME Akeno optical upper limits
  40. GRB 151229A: Fermi GBM observation
  41. GRB 151228B: Fermi GBM observation
  42. LIGO/Virgo G211117: Further Swift-XRT sources
  43. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  44. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  45. IBAS Alert 7313 is SGR J1935+2154
  46. GRB 151221A: INTEGRAL detection of a short burst or possible SGR
  47. GRB 151216A: MAXI/GSC detection
  48. GRB 151205C: Optical follow-up observations at Kiso
  49. GRB 130831A: MASTER early OT detection and LC
  50. GRB 151205C: MAXI/GSC detection
  51. Fermi GBM trigger 470712580/151202062 is not a GRB
  52. Swift-BAT refined analysis of trigger 664624 from SGR J1819-1600
  53. Swift-BAT probable detection of an outburst from SGR J1819-1600 (AX J1818.8-1559)
  54. GRB 151120A: Swift-XRT afterglow detection
  55. Swift-BAT trigger 663164 is not a burst.
  56. GRB 151027A: Mondy optical observations
  57. LIGO/Virgo G194575: LT Spectroscopy of iPTF candidates
  58. LIGO/Virgo G194575: INAF-TNG follow-up of iPTF15dkm and iPTF15dlj
  59. GRB 151029A: MITSuME Ishigakijima upper limits
  60. GRB 151029A: LCOGT-FTS afterglow observations
  61. LIGO/Virgo G194575: VLA follow-up
  62. GRB 151029A: GROND afterglow observations
  63. GRB 151027A: LCOGT-McDonald afterglow observations
  64. LIGO/Virgo G194575: further Pan-STARRS observations of the RA=1hr localisation region
  65. LIGO/Virgo G194575: Near-infrared follow-up with OAO-WFC
  66. LIGO/Virgo G194575: MAXI/GSC observations
  67. GRB 151021A: Swift detection of a burst
  68. Fermi GBM trigger 466316973/151012187 is not a GRB
  69. Konus-Wind observation of GRB 151001B
  70. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  71. GRB 151001B: Swift detection of a burst
  72. IPN Triangulation of GRB 150922A (short/hard)
  73. LIGO/Virgo G184098: TAROT network optical observations
  74. LIGO/Virgo G184098: Observations from the TOROS collaboration
  75. LIGO/Virgo G184098: TAROT La Silla Observatory optical observations (TZAC)
  76. GRB 150911A: WHT optical imaging
  77. GRB 150910A: MITSuME Ishigakijima Optical Observation after 1 day
  78. GRB 150910A: Swift detection of a burst with an optical afterglow
  79. GRB 150907B: MASTER-SAAO early optical observations
  80. GRB 150906A: Fermi GBM detection
  81. GRB 150902A: Swift-XRT observations
  82. GRB 150831B: MASTER-IAC early optical observations
  83. Fermi GBM trigger 150829183 is not a GRB
  84. Fermi GBM trigger 150828520 is not a GRB
  85. Konus-Wind observation of GRB 150818A
  86. IPN Triangulation of GRB 150819B (short / very intense)
  87. Fermi GBM GRB Trigger 458852670: iPTF P48 Observations
  88. GRB 150728A: TSHAO optical observations
  89. Trigger 650221: Swift detection of a IGR J00291+5934
  90. SGR 1E 1841-045 (Swift trigger 649113): Terskol upper limit
  91. Trigger 649113: Swift detection of SGR 1E 1841-045
  92. Swift-XRT observations of GRB 150710A
  93. Fermi Gamma-ray Burst Monitor trigger bn150629779 is not a GRB
  94. GRB 150627A: Swift/UVOT Detection
  95. GRB 150627A: Swift-XRT afterglow detection
  96. V404 Cyg: MASTER Swift, Integral alert observations
  97. GRB 150622A: MAXI/GSC detection
  98. GRB 150608A: MAXI/GSC detection
  99. GRB 150530A: Swift detection of a burst
  100. GRB 150523A: Suzaku WAM observation of the prompt emission

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