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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"

24999 results found.

  1. GRB 241025A: VIRT Optical Upper Limit
  2. GRB241120A: OHP/T193 optical observations
  3. EP241021a and EP241026b: Keck/LRIS spectroscopic observations
  4. GRB 241120A: Mondy and AbAO optical observations
  5. EP241119a: Optical upper limits with Kinder observations
  6. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  7. EP241119a: GIT optical upper limits
  8. EP241119a : J-band observations with WINTER
  9. GRB 241120A: Fermi GBM Observation
  10. EP241119a: EP detection of a fast X-ray transient
  11. GRB241120A: a long GRB detected by INTEGRAL
  12. GRB 241112B: Mephisto further optical observations
  13. GRB 241030A: J-band observations
  14. GRB 241115a: PRIME near-infrared upper limits
  15. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  16. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  17. GRB 241115B: Fermi GBM Observation
  18. LIGO/Virgo/KAGRA S241114y: Updated Sky localization
  19. Updates to IceCube realtime alert system for muon tracks
  20. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  21. GRB 241117A: Fermi GBM Detection
  22. IceCube-Cascade 241116A: Upper limits from a search for additional neutrino events in IceCube
  23. LIGO/Virgo/KAGRA S241116cq: Updated Sky localization
  24. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  25. GRB 241115C: Fermi GBM Observation
  26. GRB 241115A: Swift-XRT afterglow detection
  27. LIGO/Virgo/KAGRA S241116cq: Identification of a GW compact binary merger candidate
  28. EP241115a/GRB 241115D: Optical upper limits with Kinder observations
  29. GRB 241115A: Mephisto upper limits
  30. GRB 241113B: Mephisto upper limits
  31. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  32. GRB 241115D / EP 241115a: SVOM/GRM observation
  33. EP241113a: Swift XRT weak detection
  34. GRB 241115A: Fermi GBM Observation
  35. GRB 241115A: LCOGT Optical Upper Limits
  36. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  37. LIGO/Virgo/KAGRA S241114bi: Updated Sky localization and EM Bright Classification
  38. LIGO/Virgo/KAGRA S241113p: Updated Sky localization
  39. EP241115a: EP detection of a fast X-ray transient
  40. Swift GRB 241115A: Global MASTER-Net observations report
  41. Fermi GRB 241115A: Global MASTER-Net observations report
  42. GRB 241115A: Swift detection of a burst
  43. EP 241113a: LBT possible optical counterpart
  44. LIGO/Virgo/KAGRA S241114bi: Upper limits from Fermi-GBM Observations
  45. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  46. GRB 241113A: Swift-BAT refined analysis
  47. LIGO/Virgo/KAGRA S241114bi: Identification of a GW compact binary merger candidate
  48. GRB 241113A: PRIME near-infrared upper limits
  49. EP241113a: Global MASTER-Net observations report
  50. GRB 241113B: J-band upper limit from WINTER
  51. GRB 241113A: J-band observations with WINTER
  52. EP241113a : J-band observations with WINTER
  53. GRB 241030A: LCO optical observation
  54. GRB 241113B: Swift-XRT observations
  55. IceCube-241113A: Upper limits from a search for additional neutrino events in IceCube
  56. GRB 241113A: 1.6m Mephisto and 50cm array optical upper limits
  57. EP241113b/GRB 241113B: EP detection of GRB 241113B
  58. Fermi-LAT gamma-ray observations of IceCube-241113A
  59. LIGO/Virgo/KAGRA S241114y: Identification of a GW compact binary merger candidate
  60. GRB 241113A: Swift-XRT refined Analysis
  61. GRB 241113A: Swift/UVOT Detection
  62. GRB 241113A: REM detection of the optical/NIR afterglow
  63. LIGO/Virgo/KAGRA S241113p: Identification of a GW compact binary merger candidate
  64. GRB 241113A: LCO optical observations
  65. GRB 241112B: GMG Optical Upper Limit
  66. GRB 241113A: Enhanced Swift-XRT position
  67. GRB241113A: LCOGT (40-cm) optical counterpart detection
  68. GRB 241113A: Swift detection of a burst with an optical counterpart
  69. SVOM/GRM detection of a short burst from SGR 1E1841-045
  70. LIGO/Virgo/KAGRA S241111bn: Updated Sky localization
  71. GRB 241112B: AbAO optical upper limit
  72. GRB 241107A: GROWTH-India telescope optical upper limit
  73. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  74. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  75. GRB 241112B: Swift-XRT afterglow detection
  76. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  77. GRB 241112B: Mephisto optical upper limits
  78. GRB 241112B: GOTO optical upper limits
  79. GRB 241107A: INTEGRAL IBIS localization
  80. LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume
  81. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  82. GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
  83. LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
  84. IPN triangulation of GRB 241107A (short/hard)
  85. GRB 241025C: VZLUSAT-2 detection
  86. GRB 241025A: VZLUSAT-2 detection
  87. GRB 241018A: cubesat Avion detection
  88. GRB 241030B: TESS detection of optical counterpart
  89. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  90. LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
  91. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  92. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  93. Integral GRB241109.89: Global MASTER-Net observations report
  94. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  95. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  96. EP241107a: AbAO optical upper limit
  97. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  98. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  99. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  100. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate

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