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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"

3118 results found.

  1. GRB 180402A: Swift-XRT refined Analysis
  2. GRB 180402A: KAIT Optical Upper Limit
  3. GRB180314A: GROND detection of the afterglow
  4. GRB 180305A: Fermi-LAT detection
  5. IPN Triangulation of GRB 180223A (long)
  6. GRB 180113A: AstroSat CZTI detection
  7. GRB 180116A CALET Gamma-Ray Burst Monitor detection
  8. GRB 180113A CALET Gamma-Ray Burst Monitor detection
  9. Konus-Wind observation of GRB 180113B
  10. GRB 180116A: MAXI/GSC detection
  11. Konus-Wind observation of GRB 180113A
  12. GRB 180113A: Fermi GBM observation
  13. GRB 180113A: Swift detection of a burst
  14. GRB 180102A: MASTER-Net robotic report
  15. IPN Triangulation of GRB 171216B
  16. GRB 171205A: CHILESCOPE optical observations
  17. GRB 171123A: Swift detection of a burst
  18. GRB 171112A: MAXI/GSC detection
  19. IPN Triangulation of GRB 171108A (short)
  20. GRB 171108A: Fermi GBM detection
  21. GRB 171102B: TShAO optical upper limit
  22. Konus-Wind observation of GRB 171027A
  23. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  24. GRB 171011A: MASTER-SAAO optical observations
  25. GRB 171011A: Swift detection of a burst
  26. LIGO/Virgo G299232: LOFAR follow-up
  27. GRB 170921A: Swift-XRT refined Analysis
  28. LIGO/Virgo G297595: NIR Observations following GW170814
  29. LIGO/Virgo G298048: AST3-2 observations of SSS17a/DLT17ck from Antarctica
  30. GRB 170912B: Swift detection of a burst
  31. LIGO/Virgo G297595: Las Cumbres Observatory Optical Follow-Up
  32. GRB 170906A: Swift/UVOT Detection
  33. LIGO/Virgo G299232: Swift-XRT sources
  34. GRB 170906A: MASTER-OAFA (Argentina) early automatic OT detection
  35. GRB 170906C: Swift-XRT observations
  36. GRB 170906A: Swift detection of a burst with an optical afterglow
  37. LIGO/Virgo G299232: LOFAR follow-up
  38. LIGO/Virgo G298048: Chandra X-ray Update on GW170817
  39. LIGO/Virgo G297595: DECam observations of BBH merger region of interest
  40. LIGO/Virgo G298048: Chandra monitoring of the X-ray emission from SSS17a
  41. LIGO/Virgo G299232: GRAWITA Asiago optical observations
  42. GRB 170827A: ePESSTO NTT afterglow candidate
  43. LIGO/Virgo G299232: LOFAR follow-up
  44. LIGO/Virgo G297595: INTEGRAL pointed follow-up observations
  45. LIGO/Virgo G299232: FOUND COINCIDENT IceCube neutrino observation
  46. LIGO/Virgo G298936 TAROT/TZAC observations
  47. LIGO/Virgo G298048: MASTER Global-Net early optical observations and the Possible KiloNova SSS17a in NGC 4993 photometry and merging rate
  48. LIGO/Virgo G298048: Near-infrared fading from Gemini-South
  49. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  50. LIGO/Virgo G298936 : Fermi-LAT search for a high-energy gamma-ray counterpart
  51. LIGO/Virgo G298389 : MAXI/GSC observations
  52. LIGO/Virgo G298048: TOROS Spectra observation with CASLEO
  53. LIGO/Virgo G298048: TOROS optical counterpart search (continuation)
  54. GRB 170817B: Insight-HXMT observation
  55. LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
  56. LIGO/Virgo G298048: Observation of the potential optical counterpart in NGC 4993
  57. LIGO/Virgo G298048: REM optical/NIR observations
  58. LIGO/Virgo G298048: Subaru HSC follow-up observations
  59. GRB 170817B: Fermi GBM detection
  60. LIGO/Virgo G298048: Potential optical counterpart discovered by Swope telescope
  61. GRB 170817A: Fermi GBM detection
  62. LIGO/Virgo G297595: Subaru Hyper Suprime-Cam follow-up observations
  63. LIGO/Virgo G297595: REM optical/NIR observations
  64. GRB 170808A: MAXI/GSC detection
  65. GRB 170804A: Swift/UVOT Detection
  66. GRB 170804A: Enhanced Swift-XRT position
  67. GRB 170804A: Swift detection of a burst with optical counterpart
  68. GRB 170728B: MASTER-IAC first minute short GRB early OT detection
  69. GRB 170728B, Swift-BAT refined analysis
  70. GRB 170728B: LT afterglow confirmation
  71. Fermi GBM trigger 522470841/170723116 is not a GRB
  72. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  73. GRB 170711A: ISON/Terskol and AbAO optical observations
  74. GRB 170711A: Prompt enhanced Swift-XRT position
  75. IPN Triangulation of GRB 170708A (short)
  76. GRB 170710A: Swift detection of a burst
  77. GRB 170705A: MASTER-OAFA early OT observations
  78. GRB 170705A: Swift detection of a burst with an optical counterpart
  79. GRB 170626A: TShAO optical observations
  80. GRB 170531B: Swift/UVOT Detection
  81. GRB 170519A: CrAO optical observations
  82. Konus-Wind observation of GRB 170527A
  83. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  84. GRB 170522A: Global MASTER-Net job
  85. IPN Triangulation of GRB 170522B (long/intense)
  86. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  87. LIGO/Virgo G284239: TZAC TAROT network observations with TRE/TCA/TCH
  88. GRB 170423A: Fermi GBM detection
  89. Swift Trigger 748858: MASTER-OAFA early optical observations
  90. IPN Triangulation of GRB 170403A (short)
  91. DOAO 1m telescope V, R, I observation of GRB 170317A
  92. GRB 170317A: Swift detection of a burst with an optical counterpart
  93. LIGO/Virgo G277583: ERRATUM LV GCN 20871: TAROT Calern (TCA) observations
  94. LIGO/Virgo G277583: TAROT Calern (TCA) observations
  95. LIGO/Virgo G277583: SVOM/Mini-GWAC observations of the initial skymap
  96. LIGO/Virgo G270580: optical observations and classification of PS and MASTER sources
  97. IPN Triangulation of GRB 170305A (short)
  98. LIGO/Virgo G275697: Further Swift-XRT sources
  99. LIGO/Virgo G275697: SVOM/Mini-GWAC observations of the initial skymap
  100. LIGO/Virgo G275697: iPTF Optical Transient Candidates

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