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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.

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

24817 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-200421A
  2. IceCube-200421A: No Neutrino Counterpart in ANTARES data
  3. IceCube-200421A: No significant detection in HAWC
  4. IceCube-200421A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  5. GRB 200412B: continued Mondy and Terskol optical observations
  6. GRB 200412B: continued Terskol optical observations
  7. GRB 200412B: continued AbAO, Mondy, TSHAO, Terskol optical observations
  8. GRB 200410A: Optical upper limit
  9. GRB 200416A: Swift/UVOT Detection
  10. GRB 200416A: Swift-BAT refined analysis
  11. GRB 200412B: Swift XRT confirmation of afterglow and UVOT upper limits
  12. GRB 200415A: MASTER imspection and possible localisation
  13. GRB200412B: GROWTH India detection of afterglow
  14. Konus-Wind observation of GRB 200415A (a magnetar Giant Flare in Sculptor Galaxy?)
  15. GRB 200416A: Swift-XRT refined Analysis
  16. GRB 200412B: continued Tautenburg observations
  17. GRB 200416A: Fermi GBM observation
  18. GRB 200416A: Swift detection of a burst with an optical afterglow
  19. GRB 200415A: Fermi GBM observation
  20. IPN triangulation of GRB 200415A (possible Magnetar Giant Flare in Sculptor Galaxy?)
  21. GRB 200412B: Mondy optical observations
  22. GRB 200412B: continued Tautenburg observations
  23. GRB 200415A: BALROG localization (Fermi Trigger 608633290 / GRB 200415367)
  24. GRB 200410A: Swift-BAT refined analysis
  25. GRB 200412B: Tautenburg observations
  26. GRB 200412B: contunued AbAO optical observations
  27. GRB 200412B: SAO RAS observations of OT
  28. IceCube-200410A: No significant detection in HAWC
  29. GRB 200412B: Tautenburg observations
  30. GRB 200412B: AbAO optical observations
  31. GRB 200412B: Insight-HXMT/HE detection
  32. IceCube-200410A : Upper limits from Insight-HXMT/HE observations
  33. GRB 200412B: Swift-XRT afterglow detection
  34. Fermi GRB 200412A: Global MASTER-Net observations report
  35. GRB 200412B: Fermi GBM detection
  36. IceCube-200410A: Upper limits from a search for additional neutrino events in IceCube
  37. GRB 200412A: Fermi GBM detection
  38. GRB 200412B: BALROG localization (Fermi Trigger 608375325 / GRB 200412381)
  39. GRB 200412A: BALROG localization (Fermi Trigger 608367436 / GRB 200412290)
  40. GRB 200411A: Swift-BAT refined analysis
  41. Fermi-LAT Gamma-ray Observations of IceCube-200410A
  42. GRB 200411A: Swift-XRT refined Analysis
  43. GRB 200411A: Swift/UVOT Upper Limits
  44. GRB 200411A: Enhanced Swift-XRT position
  45. IceCube-200410A: Possible associated excess in INTEGRAL SPI-ACS prompt observation
  46. GRB 200411A: Swift detection of a short burst
  47. GRB 200410A: Swift/UVOT Detection
  48. LIGO/Virgo S200225q: Swift XRT observations, 1 X-ray sources
  49. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  50. GRB 200410A: Swift-XRT refined Analysis
  51. GRB 200410A: Enhanced Swift-XRT position
  52. GRB 200409A: Swift-BAT refined analysis
  53. GRB 200410A: Swift detection of a burst with a possible optical counterpart
  54. GRB 200405B: ATCA follow-up and ASKAP limits on pre-burst radio emission
  55. Baksan Neutrino Observatory Alert 200408.26: Global MASTER-Net observations report
  56. Fermi GBM Sub-Threshold Detection of GRB 200409A
  57. GRB 200409A: Swift-XRT refined Analysis
  58. GRB 200409A: Enhanced Swift-XRT position
  59. GRB 200409A: Swift detection of a burst with an optical counterpart
  60. GRB 200405B: LCO Optical Upper Limits
  61. GRB 200405B: Swift-XRT observations
  62. GRB 200405B: Swift/BAT-GUANO detection and *possible* arcminute localization of a short GRB
  63. GRB 200404A: BALROG localization (Fermi Trigger 607712227 / GRB 200404706)
  64. LIGO/Virgo S200316bj: Upper limits from Konus-Wind observations
  65. LIGO/Virgo S200311bg: Upper limits from Konus-Wind observations
  66. LIGO/Virgo S200302c: Upper limits from Konus-Wind observations
  67. LIGO/Virgo S200225q: Upper limits from Konus-Wind observations
  68. LIGO/Virgo S200224ca: Upper limits from Konus-Wind observations
  69. GRB 200402B: BALROG localization (Fermi Trigger 607537834 / GRB 200402688)
  70. GRB 200402A: BALROG localization (Fermi Trigger 607513182 / GRB 200402403)
  71. GRB 200325B: Optical upper limit
  72. GRB 200325B: further Swift-XRT observations
  73. GRB 200401A: Fermi GBM Final Real-time Localization
  74. GRB 200325B: Tautenburg observations
  75. IPN triangulation of GRB 200327A (short)
  76. GRB 200327A: AGILE/MCAL observations
  77. GRB 200325B: Fermi GBM observation
  78. GRB 200325B: Swift-XRT and UVOT observations
  79. GRB 200325B: LCO Optical Detection
  80. GRB 200326B: AstroSat LAXPC detection
  81. GRB 200325A: Fermi GBM observation
  82. GRB 200325B: Mondy and CrAO observations, Master MASTER OT J111012.51+274912.8 confirmation
  83. GRB 200324A: AROMA-N Optical Observation
  84. GRB 200324A, Swift-BAT refined analysis
  85. GRB 200324A:: TSHAO optical upper limit
  86. GRB 200324A: Swift/UVOT Upper Limits
  87. GRB 200325A: AGILE/MCAL observations
  88. GRB 200324A: LCO Optical Upper Limit
  89. GRB 200324A: Swift-XRT refined Analysis
  90. GRB 200324A: Konkoly Obs. optical upper limit
  91. GRB 200324A: NOT optical upper limit
  92. GRB 200324A: Tautenburg observations
  93. GRB 200324A: Enhanced Swift-XRT position
  94. GRB 200324A: Swift detection of a burst
  95. GRB 200323A: Fermi GBM detection
  96. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC-F30 observations
  97. LIGO/Virgo S200316bj: Updated Sky Localization and EM Bright Classification
  98. GRB 200320B: MAXI/GSC detection
  99. GRB 200319A: BALROG localization (Fermi Trigger 606296685 / GRB 200319323)
  100. Chandra observations of GW170817 at 2.5 years since merger (All epochs 4 of 4)

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