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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"

24827 results found.

  1. Fermi trigger No 582159815 Global MASTER-Net observations report
  2. GRB 190613B: SEDM Observations
  3. GRB 190613A: SEDM Observations
  4. GRB 190610A: Swift/UVOT Upper Limits
  5. GRB 190610A: Swift-XRT observations
  6. GRB 190613B: Optical observation from Asiago Schmidt
  7. GRB 190613B: GROND Detection of the Optical/NIR Afterglow
  8. GRB 190613B: Insight-HXMT/HE detection
  9. GRB 190613B: Optical observations from NOT
  10. GRB 190613B: Swift-XRT refined Analysis
  11. GRB 190613B: Swift-BAT refined analysis
  12. GRB 190613A, Swift-BAT refined analysis
  13. GRB 190613B: Swift/UVOT Detection
  14. GRB 190613A: Fermi GBM detection
  15. GRB 190613A: Swift/UVOT Detection
  16. GRB 190613B: Fermi GBM observation
  17. GRB 190611B: BALROG localization (Fermi Trigger 581986074 / GRB 190611950)
  18. GRB 190613B: Enhanced Swift-XRT position
  19. IPN Triangulation of GRB 190611B
  20. GRB 190613A: Swift-XRT refined Analysis
  21. GRB 190613A: Enhanced Swift-XRT position
  22. GRB 190613B: BALROG localization (Fermi Trigger 582115625 / GRB 190613449)
  23. GRB 190613B: Swift detection of a burst with an optical counterpart
  24. GRB 190613A: MASTER OT detection
  25. GRB 190613A: BALROG localization (Fermi Trigger 582091643 / GRB 190613172)
  26. GRB 190613A: Swift detection of a burst with an optical counterpart
  27. Fermi trigger No 581986074 Global MASTER-Net observations report
  28. GRB 190611B: Fermi GBM detection
  29. GRB 190611A: Swift-XRT refined Analysis
  30. GRB 190611A: Swift/UVOT Upper Limits
  31. GRB 190611A: Optical observations from VLT/FORS2
  32. GRB 190611A, Swift-BAT refined analysis
  33. GRB 190611A: Enhanced Swift-XRT position
  34. GRB 190611A: Swift detection of a burst
  35. GRB 190610A: Swift-BAT refined analysis
  36. GRB 190610A: Insight-HXMT/HE detection
  37. GRB190610B: BALROG localization (Fermi Trigger 581882394 / GRB 190610750)
  38. GRB 190610A: Swift detection of a short burst
  39. GRB190609A: BALROG localization (Fermi Trigger 581758450 / GRB 190609315)
  40. GRB 190606A: Insight-HXMT/HE detection
  41. LIGO/Virgo S190425z: Swift UVOT - no new sources identified, and a summary of the Swift UVOT processing of GW triggers.
  42. GRB 190604B: VLT Afterglow Detection
  43. GRB 190605B: Insight-HXMT/HE detection
  44. GRB 190604A: Insight-HXMT/HE detection
  45. GRB 190604B: Kitab observatory optical upper limit
  46. GRB 190604B: Swift-BAT refined analysis
  47. GRB 190604B: BOOTES-3 early optical limits
  48. GRB 190604B: Swift-XRT refined Analysis
  49. GRB190604B: GROWTH-India telescope followup - no optical counterpart found
  50. GRB190604B: Swift/UVOT detection
  51. GRB 190604B: Enhanced Swift-XRT position
  52. GRB190530A: Photometric follow-up with GROWTH-India telescope
  53. GRB 190604B: Swift detection of a burst
  54. Fermi trigger No 581337762 Global MASTER-Net observations report
  55. GRB190604A: BALROG localization (Fermi Trigger 581337762 / GRB 190604446)
  56. LIGO/Virgo S190602aq: Upper limits from CALET observations
  57. LIGO/Virgo S190602aq: Upper limits from Insight-HXMT/HE observations
  58. GRB 190531B: Swift/UVOT Upper Limits
  59. GRB 190530A: R-band observation from HCT
  60. LIGO/Virgo S190602aq: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  61. LIGO/Virgo S190602aq: upper limit in INTEGRAL SPI-ACS prompt observations
  62. LIGO/Virgo S190602aq: No counterpart candidates in Fermi-LAT observations
  63. LIGO/Virgo S190602aq: No counterpart candidates in the Swift/BAT Observations
  64. LIGO/Virgo S190602aq: Upper limits from Fermi-GBM Observations
  65. LIGO/Virgo S190602aq: Upper limits from AGILE-GRID observations
  66. LIGO/Virgo S190602aq: No counterpart candidate in AGILE-MCAL observations
  67. LIGO/Virgo S190602aq: Coverage and upper limits from MAXI/GSC observations
  68. LIGO/Virgo S190602aq: No neutrino counterpart candidates in ANTARES search
  69. LIGO/Virgo S190602aq: No counterpart candidates in HAWC observations
  70. LIGO/Virgo S190602aq: Identification of a GW compact binary merger candidate
  71. LIGO/Virgo S190602aq: Upper limits from IceCube neutrino searches
  72. Konus-Wind observation of extremely bright GRB 190530A
  73. GRB 190530A: Insight-HXMT/HE detection
  74. GRB 190531B: Insight-HXMT/HE detection
  75. GRB 190531B: VLT optical upper limit
  76. GRB 190530A: SAO RAS optical observations
  77. GRB 190531B: Swift-XRT afterglow detection
  78. GRB 190531B: Fermi GBM observations
  79. GRB 190530A: Swift/UVOT Detection
  80. GRB 190530A: Steep afterglow decay found by OSN
  81. Fermi Trigger 581026217 / GRB 190531840 / GRB190531A: BALROG localization
  82. GRB 190530A: Fermi GBM observation
  83. GRB 190530A: COATLI Optical Detection of the Fading Afterglow
  84. GRB 190530A: Swift-XRT afterglow detection
  85. GRB 190530A: GWAC-F30 optical detection
  86. GRB 190530A: OAJ optical detection
  87. GRB 190530A: NOT photometry and spectroscopy
  88. Fermi GRB190530.43 Global MASTER-Net observations report
  89. GRB 190530A: Bright afterglow confirmed by OSN
  90. GRB 190530A: AGILE/GRID analysis
  91. Fermi Trigger 580904353 / GRB 190530430 / GRB190530A: BALROG localization
  92. LIGO/Virgo S190521r: CNEOST follow-up observations
  93. GRB 190525A: Insight-HXMT/HE detection
  94. LIGO/Virgo S190521r: Kanata optical/NIR follow-up observations of the CNEOST Transient
  95. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC-F30 observations.
  96. LIGO/Virgo S190521r: No optical counterpart from SVOM/GWAC observations.
  97. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC-F30 observations.
  98. LIGO/Virgo S190521g: No optical counterpart from SVOM/GWAC observations.
  99. Konus-Wind observation of GRB 190519A
  100. LIGO/Virgo S190521g: Upper limits from Insight-HXMT/HE observations

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