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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"

5401 results found.

  1. GRB 160131A: LCOGT-FTN optical afterglow observations
  2. GRB 160127A: VLA Detection
  3. GRB 160127A: Swift/UVOT Detection
  4. GRB 160127A: Swift detection of a burst with an optical counterpart
  5. GRB160119A: BOOTES-2/TELMA Early Upper Limits
  6. LIGO/Virgo G184098: MASTER final result
  7. GRB 160117B: Early iTelescope observation
  8. GRB 160119A: Swift detection of a burst
  9. GRB 160117B: VLT/X-shooter spectroscopy
  10. LIGO/Virgo G211117: Preliminary VLA observation summary of PS15dpn
  11. IPN Triangulation of GRB 160113A
  12. LIGO/Virgo G211117: Further Swift-XRT sources
  13. LIGO/Virgo G211117: Swift observations of PS15dpn
  14. LIGO/Virgo G211117: VISTA imaging
  15. GRB 160104A: Continued MITSuME Akeno Optical Observation
  16. LIGO/Virgo G211117: Subaru Hyper Suprime-Cam follow-up observation
  17. GRB 160107A: MAXI/GSC detection
  18. IPN Triangulation of GRB 151225A (short/hard)
  19. LIGO/Virgo G211117: Further Swift-XRT sources
  20. LIGO/Virgo G211117: Liverpool Telescope classification of EM candidates
  21. LIGO/Virgo G211117: Summary of Pan-STARRS transients
  22. GRB 160104B: MAXI/GSC detection
  23. LIGO/Virgo G211117: LOFAR follow-up
  24. LIGO/Virgo G211117: PESSTO classification of Pan-STARRS transients
  25. LIGO/Virgo G211117: CSS/CRTS observations on 29/30 Dec 2015 UT
  26. GRB 160102A: MAXI/GSC detection
  27. LIGO/Virgo G211117: 44 transients from Pan-STARRS data during 2015-12-28/30
  28. LIGO/Virgo G211117: MAXI/GSC observations
  29. LIGO/Virgo G211117: LBT Follow-up of iPTF15fen
  30. LIGO/Virgo G211117: MAGIC very-high energy gamma-ray observations
  31. LIGO/Virgo G211117: SkyMapper observations and transient candidate
  32. LIGO/Virgo G211117: Optical Observations with Kiso Schmidt telescope and KWFC
  33. LIGO/Virgo G211117: List of near-term future observation regions by Project Mini-GWAC of SVOM
  34. LIGO/Virgo G211117: iPTF Optical Transient Candidates
  35. LIGO/Virgo G211117: La Silla - QUEST observations 2015 Dec 28, 29
  36. LIGO/Virgo G211117: Further Swift-XRT sources
  37. GRB 151228A: T60 observations
  38. LIGO/Virgo G211117: Optical NIR observation with Kanata telescope
  39. LIGO/Virgo G211117: Optical follow-up with Kanata telescope
  40. LIGO/Virgo G211117: MASTER Observations and Inspection + OT
  41. LIGO/Virgo G211117: INTEGRAL was inactive at the time of the event
  42. GRB 151228A: Fermi GBM observation
  43. LIGO/Virgo G211117: INAF VST-ESO PARANAL observations
  44. LIGO/Virgo G211117: Further Swift-XRT sources
  45. GRB 151228A: Swift detection of a short burst
  46. LIGO/Virgo G211117: Identification of a GW CBC Candidate
  47. GRB 151212A iTelescope observation
  48. V404Cyg Swift Trigger 668097:
  49. GRB 151216A: MAXI/GSC detection
  50. GRB151215A: Early optical light curve from pt5m, La Palma
  51. GRB 151215A: MASTER early OT detection and light curve
  52. GRB 151215A: Swift detection of a burst
  53. GRB 151212A: GROND Optical Afterglow Candidate
  54. GRB 151212A: Swift-XRT afterglow detection
  55. GRB 151212A: MAXI/GSC detection
  56. GRB 151210A: GROND Afterglow Confirmation
  57. GRB 151210A: Optical afterglow candidate from LCOGT-Cerro Tololo
  58. GRB 151210A: Swift detection of a burst
  59. GRB 151205C: Optical follow-up observations at Kiso
  60. Swift detection of 4U 1850-03
  61. GRB 130831A: MASTER early OT detection and LC
  62. Fermi GBM trigger 470375959/151128166 is not a GRB
  63. GRB 151118A iTelescope observation
  64. GRB 151118A: Early optical limit from pt5m, La Palma
  65. GRB 151118A: ISON-NM early optical limit
  66. GRB GRB 151118A: MASTER-NET optical observations
  67. GRB 151118A: Optical observations from OSN
  68. GRB 151118A: Swift detection of a burst
  69. GRB 151114A: Swift/UVOT Detection
  70. GRB 151114A: Swift detection of a burst with an optical counterpart
  71. GRB 151112A: MAXI/GSC detection
  72. GRB 151111A: GROND marginal detection of a afterglow candidate
  73. GRB 151111A: LCOGT-FTS afterglow observations
  74. LIGO/Virgo G194575: La Silla QUEST, Pan-STARRS and PESSTO observations of iPTF15dld
  75. LIGO/Virgo G194575: VLA follow-up
  76. LIGO/Virgo G194575: INAF-TNG follow-up of iPTF15dkm and iPTF15dlj
  77. GRB 151027A: MAXI/GSC detection
  78. Konus-Wind observation of GRB 151027A
  79. GRB 151027B: VLT/X-shooter redshift
  80. LIGO/Virgo G194575: iPTF Optical Transient Candidates
  81. GRB 151027A: Early RAPTOR Observations
  82. LIGO/Virgo G194575: MASTER Optical Inspection
  83. GRB 151027A: Fermi GBM observation
  84. GRB 151027A : ISON-NM early optical detection
  85. GRB 151027A: Swift detection of a burst with a bright optical afterglow
  86. GRB 151021A: Skynet PROMPT-CTIO/DSO17 observations of the optical afterglow
  87. LIGO/Virgo G194575: Kanata/J-GEM optical follow-up
  88. GRB 151023A
  89. LIGO/Virgo G194575: LOFAR follow-up
  90. LIGO/Virgo G184098: Further VST-ESO PARANAL observations
  91. LIGO/VIRGO G184098 : PESSTO classification of PS15cbm in the northern region
  92. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  93. LIGO/Virgo G184098: ongoing Pan-STARRS search for optical transients
  94. IPN Triangulation of GRB 150919A (short / hard)
  95. LIGO/Virgo G184098: Pan-STARRS1 observations of the northern sky region
  96. LIGO/Virgo G184098: Observations from the TOROS collaboration
  97. LIGO/Virgo G184098: iPTF Optical Transient Candidates
  98. LIGO/Virgo G184098: Swift follow-up observations
  99. GRB 150910A: TSHAO optical observations
  100. GRB 150915A: MASTER-NET optical observations

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