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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28050 results found.

  1. AT LIGO-Virgo S190421ar: AGILE GRID observations
  2. LIGO/Virgo S190421ar: Identification of a GW compact binary merger candidate
  3. LIGO-Virgo S190421ar: AGILE MCAL observations
  4. LIGO/Virgo S190412m: SVOM/GWAC observations of the initial skymap
  5. Fermi Trigger 577360542 / GRB 190419414 / GRB190419A: BALROG localization
  6. GRB 190326A: Swift XRT and UVOT follow-up observations
  7. IPN Triangulation of GRB 190415A
  8. GRB 190415A: Insight-HXMT/HE detection
  9. Fermi Trigger 576994194 / GRB 190415173 / : BALROG localization
  10. LIGO/Virgo S190412m: Palomar Gattini-IR Wide-field Infrared Follow-up
  11. GRB 190411A: Insight-HXMT/HE detection
  12. LIGO/Virgo S190412m: GOTO optical coverage - no notable counterparts
  13. LIGO/Virgo S190412m: Fermi-LAT search for a high-energy gamma-ray counterpart
  14. LIGO/Virgo S190412m: Swift/BAT data search
  15. LIGO/Virgo S190412m: J-GEM optical/NIR follow-up observations
  16. LIGO/Virgo S190412m: Fermi-GBM Observations
  17. LIGO/Virgo S190412m: MAXI/GSC Observations
  18. LIGO-Virgo S190412m: AGILE GRID observations
  19. LIGO/Virgo S190412m: Insight-HXMT/HE observation
  20. LIGO/Virgo S190412m/G329483: ANTARES neutrino search
  21. LIGO/Virgo S190412m: Hobby-Eberly Telescope VIRUS observations of target galaxies.
  22. LIGO/Virgo S190412m: HAWC follow-up
  23. INTEGRAL prompt observation of S190412m
  24. LIGO-Virgo S190412m: AGILE preliminary analysis
  25. LIGO/Virgo S190412m: Identification of a GW binary merger candidate
  26. LIGO/Virgo S190408an: GROND Observations of MASTER OT J154209.55-431742.2
  27. LIGO/Virgo S190408an: Pan-STARRS observations and transients in the skymap
  28. IPN triangulation of GRB 190409B (short)
  29. IceCube-190331A: Swift-XRT Follow-up Observations
  30. GRB 190409A: ground analysis reveals a likely spurious event
  31. LIGO/Virgo S190408an: MAXI/GSC Observations
  32. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  33. LIGO/Virgo S190408an: CALET Observations
  34. LIGO/Virgo S190408an: TMTS Optical Observation
  35. LIGO/Virgo S190408an: DDOTI/OAN Optical Observations
  36. LIGO/Virgo S190408an: HMT optical observations
  37. LIGO/Virgo S190408an: MASTER 3 OT's more detection
  38. Konus-Wind observation of GRB 190404B
  39. LIGO/Virgo ST190408an: Fermi-LAT search for a high-energy gamma-ray counterpart
  40. GRB 190409A: Swift detection of a possible burst
  41. LIGO-Virgo S190408an: further AGILE GRID observations after T0
  42. LIGO/Virgo S190408an: SAGUARO follow-up observations
  43. LIGO/Virgo S190408an: MASTER OT is 27 day old ATLAS SN candidate and unrelated
  44. LIGO/Virgo S190408an: Insight-HXMT/HE observation
  45. LIGO/Virgo S190408an: MASTER OT detection
  46. LIGO/Virgo S190408an: Swift/BAT data search
  47. LIGO/Virgo S190408an: KMTNet observation
  48. CORRECTED TARGET NAME: GRB 190408A: MAXI/GSC detection
  49. GRB 140408A: MAXI/GSC detection
  50. LIGO-Virgo S190408an: AGILE GRID observations
  51. LIGO/Virgo S190408an: Identification of a GW binary merger candidate
  52. LIGO-Virgo S190408an: HAWC follow-up
  53. INTEGRAL observation of S190408an
  54. LIGO-Virgo GW S190408an: J-GEM optical/NIR follow-up observations
  55. LIGO-Virgo S190408an: AGILE MCAL observations
  56. GRB 190404C: Swift-XRT afterglow detection
  57. Fermi TriggNum 576054086 (GRB 1904204.29) / MASTER OT J071404.52+550304.2: CrAO optical observations
  58. Fermi Trigger 576356086 / GRB 190407788 / : BALROG localization
  59. Fermi Trigger 576346051 / GRB 190407672 / GRB 190407A: BALROG localization
  60. GRB 190404C: Swift-XRT observations
  61. Swift GRB 190331B: Further Swift-XRT observations
  62. GRB190404C: GROWTH-India discovery of optical counterpart
  63. GRB 140404C: MAXI/GSC detection
  64. GRB 140404B: MAXI/GSC detection
  65. GRB 190330A: MITSuME Akeno and Okayama optical upper limits
  66. Trigger 896552: Swift detection of PSR B1055-52
  67. LIGO/Virgo: Announcing the start of Observing Run 3 (O3) and the beginning of the public gravitational-wave alert era
  68. GRB 190331B: Swift observations of a ground-detected burst
  69. Fermi-LAT Gamma-ray Observations of IceCube-190331A
  70. Search for additional neutrino events from the direction of IceCube-190331A with IceCube
  71. GRB 190401A: Insight-HXMT/HE detection
  72. GRB 190331C: Insight-HXMT/HE detection
  73. GRB 190331A: Insight-HXMT/HE detection
  74. GRB 190330A: Insight-HXMT/HE detection
  75. GRB 190331A: Fermi GBM detection
  76. GRB 190331A, Swift-BAT refined analysis
  77. Fermi Trigger 575656777 / GRB 190330694 / GRB 190330A: BALROG localization
  78. MAGIC follow-up of the X-ray flares of LS I +61�303 dete
  79. Swift Trigger 895503 is not a GRB
  80. Swift Trigger 895479: Detection of GRO J2058+42
  81. GRB 190326A: Swift-BAT refined analysis - a soft-short GRB or an SGR
  82. GRB 190326B: Insight-HXMT/HE detection
  83. GRB 190326A: Insight-HXMT/HE detection
  84. Swift Trigger 895257: Detection of GRO J2058+42 in outburst
  85. GRB 190324A: Swift/UVOT Observations
  86. GRB 190326B: Fermi GBM detection
  87. GRB 190324B: Insight-HXMT/HE detection
  88. GRB 190324A: Insight-HXMT/HE detection
  89. Fermi Trigger 575278303 / GRB 190326314 / GRB190326B: BALROG localization
  90. Fermi Trigger 575251142 / GRB 190325999 / GRB 190325A: BALROG localization
  91. GRB 190324A: Swift-BAT refined analysis
  92. GRB 190323A: Insight-HXMT/HE detection
  93. GRB 190324A: Swift-XRT refined Analysis
  94. GRB 190324A: Fermi GBM observation
  95. GRB 190324A: Enhanced Swift-XRT position
  96. Further Chandra observations of GW170817 ~581-583 days since merger
  97. GRB 190321A: Insight-HXMT/HE detection
  98. GRB 190324A: Swift-XRT observations
  99. GRB 190324A: Swift/UVOT afterglow candidate
  100. Fermi Trigger 575160247 / GRB 190324947: BALROG localization

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