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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"

11756 results found.

  1. Fermi trigger No 755485387: Global MASTER-Net observations report
  2. GRB 241207B: Fermi GBM Observation
  3. GRB 241209D: Swift-XRT refined Analysis
  4. GRB 241209D: COLIBRÍ detection of the afterglow
  5. Fermi GRB 241209D: Global MASTER-Net observations report
  6. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  7. Swift GRB 241209D: Global MASTER-Net observations report
  8. Fermi GRB 241209A: Global MASTER-Net observations report
  9. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  10. EP241208a: EP detection of a fast X-ray transient
  11. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  12. AT2024adec: X-ray Upper Limits from EP-FXT Observation
  13. GRB 241207C: MAXI/GSC detection
  14. GRB 241207B: Fermi GBM Final Real-time Localization
  15. Fermi GRB 241207A: Global MASTER-Net observations report
  16. EP241206a: Global MASTER-Net observations report
  17. EP241206a: EP detection of a fast X-ray transient
  18. GRB 241206A: Fermi GBM observation
  19. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  20. EP241113a: Keck/LRIS spectroscopic observation and tentative redshift
  21. Fermi GRB 241206A: Global MASTER-Net observations report
  22. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  23. GRB 241204A: Fermi-LAT detection
  24. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  25. Konus-Wind detection of GRB 241130A
  26. EP241201a: BOOTES-5 optical upper limit
  27. EP241202b: EP detection of a fast X-ray transient
  28. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  29. EP241201a: Global MASTER-Net observations report
  30. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  31. Fermi trigger No 754701230: Global MASTER-Net observations report
  32. Konus-Wind detection of GRB 241114B
  33. LIGO/Virgo/KAGRA S241130n: Identification of a GW compact binary merger candidate
  34. Fermi-LAT gamma-ray observations of IceCube-241127A
  35. LIGO/Virgo/KAGRA S241129aa: Identification of a GW compact binary merger candidate
  36. GRB 241128A: Swift-XRT refined Analysis
  37. LIGO/Virgo S241127aj: GRANDMA/FRAM-CTA-N Observations
  38. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  39. GRB 241127A: Swift-XRT refined Analysis
  40. GRB 241127A: Swift detection of a burst with an optical counterpart
  41. Swift GRB241127.91: Global MASTER-Net observations report
  42. Swift GRB241127.91: Global MASTER-Net OT detection
  43. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  44. LIGO/Virgo/KAGRA S241127aj: NED Galaxies in the Localization Volume
  45. EP241126a: EP-FXT follow-up observation update
  46. EP241126a: EP detection of a fast X-ray transient
  47. GECAM detection of a short burst from SGR 1830
  48. LIGO/VIRGO/KAGRA S241125n: GROWTH-India telescope optical observations
  49. LIGO/Virgo S241125n: Swift XRT observations, 5 X-ray sources
  50. Konus-Wind detection of GRB 241115D / EP 241115a
  51. LIGO/Virgo/KAGRA S241125n: Upper limits from Konus-Wind observations
  52. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  53. LIGO/Virgo/KAGRA S241125n: Updated Coincidence with External Event
  54. LIGO/Virgo/KAGRA S241125n: Swift/BAT-GUANO candidate counterpart
  55. GRB 241120A: GRBAlpha detection
  56. Konus-Wind detection of GRB 241117A
  57. GRB 241105A: ATCA radio detection
  58. Konus-Wind detection of GRB 241120A
  59. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  60. GRB 241120A: Mondy and AbAO optical observations
  61. EP trigger ID 01709122294: the X-ray transient is likely a stellar flare event
  62. EP241119a: GIT optical upper limits
  63. GRB 241120A: Fermi GBM Observation
  64. Integral GRB241120.25: Global MASTER-Net observations report
  65. EP241119a: Global MASTER-Net observations report
  66. EP241119a: EP detection of a fast X-ray transient
  67. GRB241120A: a long GRB detected by INTEGRAL
  68. GRB 241120A: Fermi GBM Final Real-time Localization
  69. GRB 241119A: Fermi GBM Final Real-time Localization
  70. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  71. LIGO/Virgo/KAGRA S241116cq: Upper limits from Swift/BAT-GUANO
  72. Fermi GRB 241118A: Global MASTER-Net observations report
  73. Fermi GRB 241117B: Global MASTER-Net observations report
  74. GRB 241117B: Fermi GBM Final Real-time Localization
  75. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  76. Fermi GRB 241117A: Global MASTER-Net observations report
  77. EP241115a/GRB 241115D: Swift/XRT follow-up observation
  78. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  79. EP241115a: EP detection of a fast X-ray transient
  80. GRB 241115A: Swift detection of a burst
  81. EP 241113a: LBT possible optical counterpart
  82. GRB 241113B: KAIT Optical Afterglow Candidate
  83. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  84. GRB 241030A: LCO optical observation
  85. EP241113b: Global MASTER-Net observations report
  86. Fermi-LAT gamma-ray observations of IceCube-241113A
  87. GRB 241113A: Swift-XRT refined Analysis
  88. Konus-Wind detection of GRB 241107A (short/hard)
  89. GRB 241112B: GMG Optical Upper Limit
  90. GRB 241113B : detection of a long GRB by SVOM/ECLAIRs
  91. Fermi trigger No 753166198: Global MASTER-Net observations report
  92. GRB 241107A: GROWTH-India telescope optical upper limit
  93. GRB 241112B: Swift-XRT afterglow detection
  94. GRB 241112B : detection of a long GRB by SVOM/ECLAIRs
  95. GRB 241107A: INTEGRAL IBIS localization
  96. LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume
  97. GRB 241018A: cubesat Avion detection
  98. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  99. Fermi trigger No 752878030: Global MASTER-Net observations report
  100. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations

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