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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"

104 results found.

  1. GRB260310A: Palomar 60-inch photometry of an extremely bright late-time afterglow with a temporal break at 8 days
  2. GRB 230307A: possibly the second highest GRB energy fluence ever identified
  3. GRB 230307A: GECAM detection of an extremely bright burst
  4. GRB 221009A: Determination of the black holes mass and spin
  5. GRB 221009A: a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger
  6. GRB 221009A: Fermi-LAT refined analysis
  7. GRB 211023A: OAJ Bright Afterglow Confirmation
  8. GRB 190114C: Possible host galaxy in Pan-STARRS
  9. GRB 180720B: Testing the universality of the newly born neutron star in BdHNe
  10. GRB 160509A: TLS Tautenburg Afterglow Detection
  11. GRB 150513A: request for X-ray follow up
  12. GRB 140330A: intense and persistent gamma-ray emission detected by AGILE
  13. GRB 130831A: VLT/FORS2 spectroscopic detection of a supernova
  14. GMRT radio observation of GRB 130603B
  15. GRB 130427A / SN 2013cq: Hubble Space Telescope Observations
  16. VLT observations of GRB 130427A
  17. GRB 130427A: Konkoly optical observations
  18. GRB 130427A:: BTA spectroscopic observations on May 10/11.
  19. GRB 130427A: Continued RATIR Optical and NIR Observations - Photometric Evidence for a New Component
  20. GRB 130427A: Skynet detections of a possible supernova
  21. GRB 130427A: Spectroscopic detection of the SN from the 10.4m GTC
  22. GRB 130427A: optical observations
  23. GRB 130514A: P60 Observations
  24. GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
  25. GRB 130427A: host galaxy observations
  26. GRB 130427A: Keck/LRIS Observations
  27. GRB 130427A: Ten nights of Skynet/PROMPT/GORT observations
  28. GRB 130427A: Continued RATIR Optical and NIR Observations
  29. GRB 130427A, LBT optical spectrum
  30. GRB 130427A, Watcher afterglow detection
  31. GRB 130427A: Excess optical emission consistent with an emerging supernova
  32. GRB 130427A: Amateur observations from Sweden
  33. GRB 130427A: Tautenburg afterglow observations
  34. GRB 130427A: RHESSI observations
  35. GRB 130427A: optical observations in CrAO
  36. GRB 130505A: E_iso record retraction
  37. GRB 130427A: correction to GCN 14487
  38. GRB 130505A: Largest E_iso ever measured
  39. GRB 130427A: Non-observation of VHE emission with HAWC
  40. GRB 130427A: Pan-STARRS 1 optical observations
  41. GRB 130427A: MITSuME Ishigakijima Optical Observation after 5 days
  42. GRB 130427A: Predictions about the occurrence of a supernova
  43. GRB 130427A: KAIT optical observations
  44. GRB 130427A: SARA-N optical observations
  45. GRB 130427A: VLA 20 GHz detection
  46. GRB 130427A: ABT optical observations
  47. GRB 130427A: High-energy neutrino search
  48. GRB 130427A: GMRT radio detection
  49. GRB 130427A: Continued GMG optical observations
  50. GRB 130427A: Nishi-Harima Optical Spectroscopic Observations
  51. GRB 130427A: photo-z of possible SDSS host galaxy
  52. GRB 130427A: high energy gamma-ray detection by AGILE
  53. GRB 130427A: Continued RATIR Optical and NIR Observations
  54. GRB 130427A: MITSuME Ishigakijima Optical Observation after 2 days
  55. GRB 130427A: Challis Observatory optical observations
  56. GRB 130427A: Continued Skynet/PROMPT Observations
  57. GRB 130427A: further GMG observations
  58. GRB 130427A: Fermi-LAT refined analysis
  59. GRB 130427A: SARA-N detection
  60. GRB 130427A: Continued RATIR Optical and NIR Observations
  61. GRB 130427A: CrAO RT-22 36 GHz observation
  62. GRB 130427A in the Ep,i - Eiso plane
  63. GRB 130427A: Improved Swift-XRT analysis
  64. GRB 130427A: MITSuME Okayama and Ishigakijima Optical Observation after 1 day
  65. GRB 130427A: Skynet/PROMPT Observations
  66. GRB 130427A: Nishi-Harima NIR Observations
  67. GRB 130427A: CARMA 3mm observations
  68. GRB 130427A : Xinglong TNT optical observation
  69. GRB 130427A: VLT/X-shooter redshift confirmation
  70. GRB 130427A optical time series
  71. GRB 130427A, Optical Observations
  72. GRB 130427A: Continued iTelescope T21 optical observations
  73. Konus-Wind observation of GRB 130427A
  74. GRB 130427A: Kanata/HOWPol optical imaging polarimetry
  75. GRB 130427A: Swift-XRT refined Analysis
  76. GRB 130427A: SPI-ACS/INTEGRAL observations
  77. GRB 130427A: Continued RATIR Optical and NIR Observations
  78. GRB 130427A: CARMA 85 GHz detection
  79. GRB 130427A: SNUO/SOAO/BOAO Observation
  80. GRB 130427A: VLA 5 GHz detection
  81. GRB 130427A: NOT optical photometry and redshift
  82. GRB 130427A: RAPTOR Bright Counterpart Before Swift Trigger
  83. GRB 130427A: T100 observations
  84. GRB 130427A: optical observations in CrAO
  85. GRB 130427A: Fermi GBM observation
  86. GRB 130427A: Fermi-LAT detection of a burst
  87. GRB 130427A: Swift-BAT refined analysis
  88. GRB 130427A: Zadko observatory - Gingin optical observations
  89. GRB 130427A: GMG optical observation
  90. GRB 130427A: MITSuME Okayama Optical Observation
  91. GRB 130427A: Optical Observations
  92. GRB 130427A: MAXI/GSC detection
  93. GRB 130427A: RATIR Optical and NIR Observations
  94. GRB 130427A: Weihai optical observations
  95. GRB 130427A: iTelescope T11 optical observations
  96. GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
  97. GRB 130427A: Gemini-North redshift
  98. GRB 130427A: MITSuME Akeno Optical observation(T0+8000s~)
  99. GRB 130427A: PAIRITEL NIR Detections
  100. GRB 130427A: Faulkes Telescope North detection

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