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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"

12111 results found.

  1. EP241021a: SAO RAS optical observations
  2. EP241021a: EP-FXT follow-up observation update
  3. GRB241017A: 1.3m DFOT optical upper limit
  4. EP241021a: EP detection of a fast X-ray transient
  5. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  6. Konus-Wind detection of GRB 241018A
  7. GRB 241018A/sb24101802: Mephisto optical upper limit
  8. GRB 240727A: VIRT Optical Upper Limit
  9. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  10. Fermi trigger No 750788395: Global MASTER-Net observations report
  11. Fermi GRB 241016B: Global MASTER-Net observations report
  12. Fermi GRB 241016A: Global MASTER-Net observations report
  13. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  14. GRB241013A: REM observations
  15. GRB 241013A: a long GRB detected by INTEGRAL
  16. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  17. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  18. GRB 241011A: Fermi GBM Final Real-time Localization
  19. GRB 241010A: Swift-XRT refined Analysis
  20. Fermi trigger No 750211959: Global MASTER-Net observations report
  21. Fermi trigger No 750291012: Global MASTER-Net observations report
  22. GRB 241010A: Swift detection of a burst with an optical counterpart
  23. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  24. GRB 241008A: Fermi-LAT detection
  25. GRB 241002B: Swift-XRT afterglow detection
  26. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  27. GRB 240910A: LBT optical observations
  28. GRB 241006A: Swift-XRT refined Analysis
  29. IceCube Alert 241006.94: Global MASTER-Net observations report
  30. GRB 241006A: Swift detection of a burst
  31. Swift GRB241006.91: Global MASTER-Net observations report
  32. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  33. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  34. Fermi trigger No 749693019: Global MASTER-Net observations report
  35. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  36. Konus-Wind detection of GRB 240926A
  37. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  38. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  39. EP240930a: Liverpool Telescope observations
  40. GRB 241002A: Swift-XRT refined Analysis
  41. GRB 241002B: GOTO optical counterpart candidate
  42. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  43. Fermi GRB 241002B: Global MASTER-Net observations report
  44. GRB 241002A: Swift detection of a burst
  45. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  46. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  47. EP240930a: GOTO optical upper limits
  48. EP EP240930a: Global MASTER-Net observations report
  49. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  50. GRB 240929A : Leavitt Observatory optical upper limit
  51. Fermi GRB 240930B: Global MASTER-Net observations report
  52. Fermi GRB 240930A: Global MASTER-Net observations report
  53. GRB 240929A long GRB detected by INTEGRAL
  54. Fermi GRB 240929A: Global MASTER-Net observations report
  55. Konus-Wind detection of GRB 240912A
  56. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  57. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  58. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  59. EP trigger ID 01709061302: the X-ray transient is likely a stellar flare event
  60. Konus-Wind detection of GRB 240905B
  61. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  62. EP240918b and EP240918c: EP-FXT follow-up observations
  63. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  64. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  65. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  66. Konus-Wind detection of GRB 240918B
  67. IPN triangulation of GRB 240918B
  68. EP trigger ID 01709059262: the X-ray transient is likely a stellar flare event
  69. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  70. LIGO/Virgo S240919bn: GOTO optical upper limits
  71. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  72. GRB 240918B: AstroSat CZTI detection
  73. LIGO/Virgo/KAGRA S240921cw: Identification of a GW compact binary merger candidate
  74. EP240919a: EP-FXT follow-up observation update
  75. EP240919a / GRB 240919A: Mondy optical upper limit
  76. EP240919a: Optical upper limit with Kinder observations
  77. GRB 240919A / EP240919a: SVOM/GRM observation
  78. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  79. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  80. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  81. EP EP240919a: Global MASTER-Net observations report
  82. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  83. EP240919a: NOT and Gemini optical observations
  84. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  85. EP240919a: EP-WXT detection of a fast X-ray transient
  86. GRB 240918B: Fermi GBM Detection
  87. EP240918a: EP observation update
  88. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  89. Fermi GRB 240918A: Global MASTER-Net observations report
  90. GRB 240918A: Fermi GBM Final Real-time Localization
  91. EP EP240918a: Global MASTER-Net observations report
  92. EP240918a: YAHPT Optical Upper Limit
  93. EP240918a: Optical upper limits with Kinder observations
  94. EP240918a: an X-ray transient detected by Einstein Probe
  95. GRB 240916A: NOT optical observation
  96. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  97. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  98. EP EP240913a: Global MASTER-Net observations report
  99. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  100. Fermi Gamma-ray Burst Monitor trigger 748124309/240915846 is not a GRB

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