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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"

12113 results found.

  1. EP241021a: VLT/FORS2 redshift z = 0.75
  2. Fermi trigger No 751449953: Global MASTER-Net observations report
  3. EP241021a: SAO RAS optical observations
  4. EP241021a: EP-FXT follow-up observation update
  5. GRB241017A: 1.3m DFOT optical upper limit
  6. EP241021a: EP detection of a fast X-ray transient
  7. IceCube-Cascade 241019A: Upper limits from a search for additional neutrino events in IceCube
  8. Konus-Wind detection of GRB 241018A
  9. GRB 241018A/sb24101802: Mephisto optical upper limit
  10. GRB 240727A: VIRT Optical Upper Limit
  11. GRB 241016B: Swift/BAT-GUANO localization skymap of a short burst
  12. Fermi trigger No 750788395: Global MASTER-Net observations report
  13. Fermi GRB 241016B: Global MASTER-Net observations report
  14. Fermi GRB 241016A: Global MASTER-Net observations report
  15. GRB 241013B: Swift/BAT-GUANO localization skymap of a burst
  16. GRB241013A: REM observations
  17. GRB 241013A: a long GRB detected by INTEGRAL
  18. LIGO/Virgo/KAGRA S241011k: NED Galaxies in the Localization Volume
  19. Fermi Gamma-ray Burst Monitor GRB trigger 750372658/241011869 (GRB 241011A) is not a GRB
  20. GRB 241011A: Fermi GBM Final Real-time Localization
  21. GRB 241010A: Swift-XRT refined Analysis
  22. Fermi trigger No 750211959: Global MASTER-Net observations report
  23. Fermi trigger No 750291012: Global MASTER-Net observations report
  24. GRB 241010A: Swift detection of a burst with an optical counterpart
  25. Fermi-LAT Gamma-ray Observations of IceCube-241006A
  26. GRB 241008A: Fermi-LAT detection
  27. GRB 241002B: Swift-XRT afterglow detection
  28. Fermi-LAT Gamma-ray Observations of NuEm-240926A
  29. GRB 240910A: LBT optical observations
  30. GRB 241006A: Swift-XRT refined Analysis
  31. IceCube Alert 241006.94: Global MASTER-Net observations report
  32. GRB 241006A: Swift detection of a burst
  33. Swift GRB241006.91: Global MASTER-Net observations report
  34. EP trigger ID 01709065118: the X-ray transient is likely a stellar flare event
  35. GRB 241001A : ECLAIRs spectral analysis and XRF classification
  36. Fermi trigger No 749693019: Global MASTER-Net observations report
  37. GRB 241002B: Swift/BAT-GUANO localization skymap of a burst
  38. Konus-Wind detection of GRB 240926A
  39. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  40. GRB 241002B: GOTO24gpc/AT 2024xbg follow-up observations update
  41. EP240930a: Liverpool Telescope observations
  42. GRB 241002A: Swift-XRT refined Analysis
  43. GRB 241002B: GOTO optical counterpart candidate
  44. GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs
  45. Fermi GRB 241002B: Global MASTER-Net observations report
  46. GRB 241002A: Swift detection of a burst
  47. GRB 240930B: Swift/BAT-GUANO localization skymap of a burst
  48. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  49. EP240930a: GOTO optical upper limits
  50. EP EP240930a: Global MASTER-Net observations report
  51. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  52. GRB 240929A : Leavitt Observatory optical upper limit
  53. Fermi GRB 240930B: Global MASTER-Net observations report
  54. Fermi GRB 240930A: Global MASTER-Net observations report
  55. GRB 240929A long GRB detected by INTEGRAL
  56. Fermi GRB 240929A: Global MASTER-Net observations report
  57. Konus-Wind detection of GRB 240912A
  58. LIGO/Virgo/KAGRA S240921cw: Upper limits from Swift/BAT-GUANO
  59. LIGO/Virgo/KAGRA S240920dw: Upper limits from Swift/BAT-GUANO
  60. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  61. EP trigger ID 01709061302: the X-ray transient is likely a stellar flare event
  62. Konus-Wind detection of GRB 240905B
  63. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  64. EP240918b and EP240918c: EP-FXT follow-up observations
  65. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  66. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  67. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  68. Konus-Wind detection of GRB 240918B
  69. IPN triangulation of GRB 240918B
  70. EP trigger ID 01709059262: the X-ray transient is likely a stellar flare event
  71. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  72. LIGO/Virgo S240919bn: GOTO optical upper limits
  73. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  74. GRB 240918B: AstroSat CZTI detection
  75. LIGO/Virgo/KAGRA S240921cw: Identification of a GW compact binary merger candidate
  76. EP240919a: EP-FXT follow-up observation update
  77. EP240919a / GRB 240919A: Mondy optical upper limit
  78. EP240919a: Optical upper limit with Kinder observations
  79. GRB 240919A / EP240919a: SVOM/GRM observation
  80. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  81. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  82. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  83. EP EP240919a: Global MASTER-Net observations report
  84. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  85. EP240919a: NOT and Gemini optical observations
  86. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  87. EP240919a: EP-WXT detection of a fast X-ray transient
  88. GRB 240918B: Fermi GBM Detection
  89. EP240918a: EP observation update
  90. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  91. Fermi GRB 240918A: Global MASTER-Net observations report
  92. GRB 240918A: Fermi GBM Final Real-time Localization
  93. EP EP240918a: Global MASTER-Net observations report
  94. EP240918a: YAHPT Optical Upper Limit
  95. EP240918a: Optical upper limits with Kinder observations
  96. EP240918a: an X-ray transient detected by Einstein Probe
  97. GRB 240916A: NOT optical observation
  98. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  99. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  100. EP EP240913a: Global MASTER-Net observations report

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