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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"

11836 results found.

  1. EP240919a: Optical upper limit with Kinder observations
  2. GRB 240919A / EP240919a: SVOM/GRM observation
  3. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  4. EP240919a: INTEGRAL SPI-ACS confirmation of reported high-energy counterpart
  5. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  6. EP EP240919a: Global MASTER-Net observations report
  7. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  8. EP240919a: NOT and Gemini optical observations
  9. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  10. EP240919a: EP-WXT detection of a fast X-ray transient
  11. GRB 240918B: Fermi GBM Detection
  12. EP240918a: EP observation update
  13. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  14. Fermi GRB 240918A: Global MASTER-Net observations report
  15. GRB 240918A: Fermi GBM Final Real-time Localization
  16. EP EP240918a: Global MASTER-Net observations report
  17. EP240918a: YAHPT Optical Upper Limit
  18. EP240918a: Optical upper limits with Kinder observations
  19. EP240918a: an X-ray transient detected by Einstein Probe
  20. GRB 240916A: NOT optical observation
  21. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  22. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  23. EP EP240913a: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  25. Fermi Gamma-ray Burst Monitor trigger 748124309/240915846 is not a GRB
  26. GRB 240914B: AstroSat CZTI detection
  27. EP240913A / GRB 240913C: AstroSat CZTI detection
  28. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  29. GRB 240914A : An intermediate duration GRB located on-board by SVOM/ECLAIRs.
  30. EP240913a: EP-WXT detection of a fast X-ray transient
  31. GRB 240913B: Fermi GBM Final Real-time Localization
  32. GRB 240912A: Swift-XRT refined Analysis
  33. GRB 240912A: NOT optical spectroscopy
  34. GRB 240912A: Swift detection of a burst with an optical counterpart
  35. GRB 240911A : a likely weak GRB detected by SVOM/ECLAIRs
  36. GRB 240825A: 7DT Optical Upper Limit
  37. LIGO/Virgo/KAGRA S240910ci: NED Galaxies in the Localization Volume
  38. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  39. EP240908a: Updates on the WXT detection result around the trigger time
  40. Fermi GRB 240910A: Global MASTER-Net observations report
  41. LIGO/Virgo/KAGRA S240908bs: Upper limits from Swift/BAT-GUANO
  42. LIGO/Virgo/KAGRA S240907cg: Upper limits from Swift/BAT-GUANO
  43. GRB 240905E: GIT optical upper limit
  44. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  45. GRB 240905B: Fermi-LAT detection
  46. GRB 240905E: SVOM/C-GFT optical upper limit
  47. GRB 240902B: AstroSat CZTI detection of a long burst
  48. GRB 240905E: Swift-XRT refined Analysis
  49. GRB 240902A: AstroSat CZTI detection of a long burst
  50. GRB 240905D: AstroSat CZTI detection
  51. GRB 240905B: AstroSat CZTI detection and localization
  52. LIGO/Virgo/KAGRA S240825ar: Upper limits from Swift/BAT-GUANO
  53. LIGO/Virgo/KAGRA S240807h: Upper limits from Swift/BAT-GUANO
  54. GRB 240825A: MeerLICHT afterglow detection
  55. Fermi trigger No 746923430: Global MASTER-Net observations report
  56. GRB 240828B: Mephisto optical upper limit
  57. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  58. GRB 240825A: MeerKAT detection
  59. GRB 240828B: J-band upper limit from WINTER
  60. GRB 240828B: GWAC-F50A optical upper limit
  61. GRB 240828B: SAO RAS optical upper limit
  62. Fermi trigger No 746587425: Global MASTER-Net observations report
  63. GRB 240828A: Swift-XRT afterglow detection
  64. GRB 240828A: Fermi-LAT detection
  65. LAT GRB240828.62: Global MASTER-Net observations report
  66. GRB 240828A: AstroSat CZTI detection of a long burst
  67. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  68. GRB 240819A as a likely X-Ray Flash
  69. GRB 240821A: PRIME near-infrared observations
  70. Fermi trigger No 746438824: Global MASTER-Net observations report
  71. GRB 240825A: TNG optical photometry and spectroscopy
  72. Konus-Wind detection of GRB 240825A (bright/long)
  73. GRB 240825A: AstroSat CZTI detection of the long bright burst
  74. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  75. GRB 240825A: Swift/UVOT Detection
  76. GRB 240825A: Swift-XRT refined Analysis
  77. GRB 240825A: Fermi-LAT detection
  78. GRB 240825A: LCO optical observations
  79. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  80. Fermi GRB 240825A: Global MASTER-Net observations report
  81. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  82. GRB 240824B: MAXI/GSC detection
  83. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  84. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  85. GRB 240821A: Colibri Optical Upper Limit
  86. GRB 240822A: AstroSat CZTI detection of a short burst
  87. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  88. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  89. Fermi trigger No 745866488: Global MASTER-Net observations report
  90. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  91. GRB 240819A: Swift-XRT observations
  92. GRB 240819A: JinShan optical upper limits on one Swift/XRT source
  93. EP240820a: EP detection of a fast X-ray transient
  94. Trigger 1249653: Swift detection of SGR 1E 1841-045 / Kes 73
  95. Fermi trigger No 745873283: Global MASTER-Net observations report
  96. Fermi trigger No 745871958: Global MASTER-Net observations report
  97. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  98. GRB 240820A: Fermi GBM Final Real-time Localization
  99. Integral GRB240816.79: Global MASTER-Net observations report
  100. GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart

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