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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"

5050 results found.

  1. GRB 171120A: Fermi-LAT detection
  2. GRB 171115A: Swift-XRT refined Analysis
  3. FACT follow-up of IceCube20171106
  4. GRB 171112A: MAXI/GSC detection
  5. IceCube-171106A: Swift Observations
  6. HAWC follow-up of IceCube-171106A
  7. GRB 171030A: MASTER inspection of the IPN error box of the short GRB.
  8. GRB 171102B: MITSuME Akeno optical upper limits
  9. GRB 171102B: Swift-XRT refined Analysis
  10. Swift Trigger 783893 is probably not a GRB
  11. GRB 171027A: Swift-XRT refined Analysis
  12. GRB 171027A: MASTER-OAFA (Argentina) early prompt optical observations
  13. GRB 171027A: Swift detection of a burst
  14. GRB 171013B CALET Gamma-Ray Burst Monitor detection
  15. GRB 171020A: Swift-XRT refined Analysis
  16. GRB 171013A: Swift detection of a possible burst
  17. GRB 171010B: Swift detection of a burst
  18. GRB 171010A: Swift-XRT afterglow detection
  19. GRB 171007A: Swift-XRT refined Analysis
  20. LIGO/Virgo G298048: LWA radio observations
  21. GRB 171004A: Swift-XRT refined Analysis
  22. LIGO/Virgo G299232: SWASP optical imaging coverage
  23. LIGO/Virgo G299232: MAGIC Cherenkov Telescopes observations
  24. LIGO/Virgo G299232: LOFAR follow-up
  25. GRB 171003A: Swift detection of a burst or a Galactic Transient
  26. GRB 171001A: Swift-XRT refined Analysis
  27. LIGO/Virgo G298048: Record of all e-MERLIN results to date on SSS17a
  28. IPN Triangulation of GRB 170921B
  29. GRB 170921A: LCO 2m telescope observations
  30. GRB 170921A: Swift-XRT refined Analysis
  31. LIGO/Virgo G298048: SSS17a photometry of CHILESCOPE observatory
  32. LIGO/Virgo G297595: NIR Observations following GW170814
  33. LIGO/Virgo G298048: AST3-2 observations of SSS17a/DLT17ck from Antarctica
  34. LIGO/Virgo G297595: DLT40 follow-up observation
  35. GRB 170912A: Swift-XRT refined Analysis
  36. LIGO/Virgo G299232: Khureltogot observations
  37. GRB 170912B: Swift-XRT refined Analysis
  38. GRB 170911A: Fermi GBM observation
  39. LIGO/Virgo G297595: Las Cumbres Observatory Optical Follow-Up
  40. GRB 170911A: MAXI/GSC detection
  41. LIGO/Virgo G298048: LWA Detection
  42. GRB 170906B: Swift-XRT refined Analysis
  43. LIGO/Virgo G299232: Swift-XRT sources
  44. GRB 170906A: Swift-XRT refined Analysis
  45. GRB 170906C: Swift-XRT refined Analysis
  46. GRB 170906A: MASTER-OAFA (Argentina) early automatic OT detection
  47. LIGO/Virgo G298389: Fermi GBM Flux Upper Limits
  48. GRB 170903A: Swift-XRT refined Analysis
  49. LIGO/Virgo G297595: DECam observations of BBH merger region of interest
  50. LIGO/Virgo G299232: GRAWITA Asiago optical observations
  51. LIGO/Virgo G296853: PIRATE observations
  52. LIGO/Virgo G299232 TZAC/TAROT observations
  53. GRB 170827A: ePESSTO NTT afterglow candidate
  54. GRB 170827A: REM optical/NIR observations
  55. GRB 170826B: Fermi GBM detection
  56. LIGO/Virgo G298936 TAROT/TZAC observations
  57. LIGO/Virgo G298936 : MAXI/GSC observations
  58. LIGO/Virgo G298048: MASTER Global-Net early optical observations and the Possible KiloNova SSS17a in NGC 4993 photometry and merging rate
  59. LIGO/VIRGO G298048: AAT/AAO spectroscopic observations of the GW counterpart candidate SSS17a/DLT17ck
  60. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  61. GRB 170822A: Swift-XRT refined Analysis
  62. LIGO/Virgo G298048: NuSTAR limits on X-ray emission
  63. LIGO/Virgo G298048: Continued VLA observations
  64. LIGO/Virgo G298048: HSC observations of the OT candidate of G298048
  65. LIGO/Virgo G298048: GROND photometry of candidate optical counterpart reveals brightening in the NIR
  66. LIGO/Virgo G298048: Rapid Evolution of Possible Counterpart
  67. LIGO/Virgo G298048: New MASTER observations of the OT in NGC 4993
  68. LIGO/Virgo G298048: REM optical/NIR observations
  69. LIGO/Virgo G298048: Subaru HSC follow-up observations
  70. LIGO/Virgo G297595: Subaru Hyper Suprime-Cam follow-up observations
  71. LIGO/Virgo G297595: REM optical/NIR observations
  72. GRB 170813A: Swift-XRT refined Analysis
  73. GRB 170810A: Swift-XRT refined Analysis
  74. LIGO/Virgo G296853: no INTEGRAL data at the time of the event
  75. LIGO/Virgo G296853: Fermi-LAT search for high-energy gamma-ray counterpart
  76. GRB 170804A: Swift-XRT refined Analysis
  77. GRB 170803A: Swift-XRT refined Analysis
  78. GRB 170728A: Swift-XRT refined Analysis
  79. GRB 170728B: Swift-XRT refined Analysis
  80. GRB 170714A: z-band afterglow candidate for OSIRIS/GTC
  81. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  82. GRB 170711A: Swift-XRT refined Analysis
  83. GRB 170710A: Swift-XRT refined Analysis
  84. GRB 170705A: Swift-XRT refined Analysis
  85. GRB 170705A: MASTER-OAFA early OT observations
  86. GRB 170629A: Swift-XRT refined Analysis
  87. GRB 170629A: Fermi GBM observation
  88. GRB 170626A: Swift-XRT refined Analysis
  89. LIGO/Virgo G288732: Fermi GBM Upper Limits for the LIGO Trigger and LAT Candidate
  90. GRB 170610A: MAXI/GSC detection
  91. LIGO/Virgo G288732 : MAXI/GSC observations
  92. GRB 170607A: Swift-XRT refined Analysis
  93. GRB 170519A: TShAO and AbAO optical observations
  94. GRB 170604A: Swift/UVOT Observations
  95. GRB 170604A: Swift-XRT refined Analysis
  96. GRB 170604A: Enhanced Swift-XRT position
  97. GRB 170604A: Swift-BAT refined analysis
  98. GRB 170604A: optical observations
  99. GRB 170604A: Swift detection of a burst
  100. GRB 170531B: Swift-BAT refined analysis

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