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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"

2724 results found.

  1. GRB180523B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 548793993)
  2. GRB 180512A: NOT upper limits
  3. GRB 180512A: Swift detection of a burst
  4. Swift trigger 831888: misidentification of 4U 1416-62
  5. GRB 180425A: Swift detection of a burst
  6. GRB 180410A: Fermi GBM observation
  7. GRB 180411A: Swift-BAT refined analysis
  8. GRB 180411A: Swift-XRT refined Analysis
  9. GRB 180411A: Swift detection of a burst
  10. GRB 180404A: Swift detection of a burst with an optical afterglow
  11. GRB 180402A: Swift-XRT refined Analysis
  12. GRB 180402A: KAIT Optical Upper Limit
  13. GRB180314A: GROND detection of the afterglow
  14. IPN Triangulation of GRB 180223A (long)
  15. GRB 180113A: AstroSat CZTI detection
  16. GRB 180116A CALET Gamma-Ray Burst Monitor detection
  17. GRB 180113A CALET Gamma-Ray Burst Monitor detection
  18. Konus-Wind observation of GRB 180113B
  19. GRB 180116A: MAXI/GSC detection
  20. Konus-Wind observation of GRB 180113A
  21. GRB 180113A: Fermi GBM observation
  22. GRB 180113A: Swift detection of a burst
  23. GRB 180102A: MASTER-Net robotic report
  24. IPN Triangulation of GRB 171216B
  25. GRB 171205A: CHILESCOPE optical observations
  26. GRB 171123A: Swift detection of a burst
  27. GRB 171112A: MAXI/GSC detection
  28. IPN Triangulation of GRB 171108A (short)
  29. GRB 171108A: Fermi GBM detection
  30. GRB 171102B: TShAO optical upper limit
  31. Konus-Wind observation of GRB 171027A
  32. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  33. GRB 171011A: MASTER-SAAO optical observations
  34. GRB 171011A: Swift detection of a burst
  35. LIGO/Virgo G299232: LOFAR follow-up
  36. GRB 170921A: Swift-XRT refined Analysis
  37. LIGO/Virgo G297595: NIR Observations following GW170814
  38. LIGO/Virgo G298048: AST3-2 observations of SSS17a/DLT17ck from Antarctica
  39. GRB 170912B: Swift detection of a burst
  40. LIGO/Virgo G297595: Las Cumbres Observatory Optical Follow-Up
  41. GRB 170906A: Swift/UVOT Detection
  42. LIGO/Virgo G299232: Swift-XRT sources
  43. GRB 170906A: MASTER-OAFA (Argentina) early automatic OT detection
  44. GRB 170906C: Swift-XRT observations
  45. GRB 170906A: Swift detection of a burst with an optical afterglow
  46. LIGO/Virgo G299232: LOFAR follow-up
  47. LIGO/Virgo G298048: Chandra X-ray Update on GW170817
  48. LIGO/Virgo G297595: DECam observations of BBH merger region of interest
  49. LIGO/Virgo G298048: Chandra monitoring of the X-ray emission from SSS17a
  50. LIGO/Virgo G299232: GRAWITA Asiago optical observations
  51. GRB 170827A: ePESSTO NTT afterglow candidate
  52. LIGO/Virgo G299232: LOFAR follow-up
  53. LIGO/Virgo G297595: INTEGRAL pointed follow-up observations
  54. LIGO/Virgo G299232: FOUND COINCIDENT IceCube neutrino observation
  55. LIGO/Virgo G298936 TAROT/TZAC observations
  56. LIGO/Virgo G298048: MASTER Global-Net early optical observations and the Possible KiloNova SSS17a in NGC 4993 photometry and merging rate
  57. LIGO/Virgo G298048: Near-infrared fading from Gemini-South
  58. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  59. LIGO/Virgo G298936 : Fermi-LAT search for a high-energy gamma-ray counterpart
  60. LIGO/Virgo G298389 : MAXI/GSC observations
  61. LIGO/Virgo G298048: TOROS Spectra observation with CASLEO
  62. LIGO/Virgo G298048: TOROS optical counterpart search (continuation)
  63. GRB 170817B: Insight-HXMT observation
  64. LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
  65. LIGO/Virgo G298048: Observation of the potential optical counterpart in NGC 4993
  66. LIGO/Virgo G298048: REM optical/NIR observations
  67. LIGO/Virgo G298048: Subaru HSC follow-up observations
  68. GRB 170817B: Fermi GBM detection
  69. LIGO/Virgo G298048: Potential optical counterpart discovered by Swope telescope
  70. GRB 170817A: Fermi GBM detection
  71. LIGO/Virgo G297595: Subaru Hyper Suprime-Cam follow-up observations
  72. LIGO/Virgo G297595: REM optical/NIR observations
  73. GRB 170808A: MAXI/GSC detection
  74. GRB 170804A: Swift/UVOT Detection
  75. GRB 170804A: Enhanced Swift-XRT position
  76. GRB 170804A: Swift detection of a burst with optical counterpart
  77. GRB 170728B: MASTER-IAC first minute short GRB early OT detection
  78. GRB 170728B, Swift-BAT refined analysis
  79. GRB 170728B: LT afterglow confirmation
  80. Fermi GBM trigger 522470841/170723116 is not a GRB
  81. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  82. GRB 170711A: ISON/Terskol and AbAO optical observations
  83. GRB 170711A: Prompt enhanced Swift-XRT position
  84. IPN Triangulation of GRB 170708A (short)
  85. GRB 170710A: Swift detection of a burst
  86. GRB 170705A: MASTER-OAFA early OT observations
  87. GRB 170705A: Swift detection of a burst with an optical counterpart
  88. GRB 170626A: TShAO optical observations
  89. GRB 170519A: CrAO optical observations
  90. Konus-Wind observation of GRB 170527A
  91. LIGO/Virgo G268556: optical observations and classification of Pan-STARRS1 transients
  92. GRB 170522A: Global MASTER-Net job
  93. IPN Triangulation of GRB 170522B (long/intense)
  94. LIGO/Virgo G277583: UH88/SNIFS classification of ATLAS and PS1 transients
  95. LIGO/Virgo G284239: TZAC TAROT network observations with TRE/TCA/TCH
  96. GRB 170423A: Fermi GBM detection
  97. Swift Trigger 748858: MASTER-OAFA early optical observations
  98. IPN Triangulation of GRB 170403A (short)
  99. DOAO 1m telescope V, R, I observation of GRB 170317A
  100. GRB 170317A: Swift detection of a burst with an optical counterpart

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