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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"

28054 results found.

  1. GRB 231118A: REM optical afterglow detection
  2. GRB 231122B: AstroSat CZTI detection
  3. GRB 231122B: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  4. GRB 231122B: Glowbug gamma-ray detection
  5. GRB 231117A: Continued GTC Observations
  6. GRB 231122A: GECAM detection
  7. GRB 231122B: GECAM detection
  8. GRB 231117A: Swift/UVOT late time observations
  9. GRB 231117A: GTC Near-Infrared Observations
  10. GRB 231117A: Swift-BAT refined analysis
  11. LIGO/Virgo/KAGRA S231118d: Upper limits from Swift/BAT-GUANO
  12. LIGO/Virgo/KAGRA S231118an: Upper limits from Swift/BAT-GUANO
  13. LIGO/Virgo/KAGRA S231114n: Upper limits from Swift/BAT-GUANO
  14. LIGO/Virgo/KAGRA S231113bb: Upper limits from Swift/BAT-GUANO
  15. LIGO/Virgo/KAGRA S231119u: Updated Sky localization and Source Classification
  16. LIGO/Virgo/KAGRA S231118ab: Updated Sky localization and Source Classification
  17. LIGO/Virgo/KAGRA S231118d: Updated Sky localization and Source Classification
  18. GRB 231118A: VZLUSAT-2 detection
  19. GRB 231117A: AMI-LA radio observations
  20. GRB 231118A: Swift-BAT refined analysis
  21. 231118A: Swift-UVOT Detection
  22. GRB231117A: Swift-UVOT detection
  23. GRB 231117A : MITSuME Akeno optical afterglow candidate detection
  24. GRB 231118B: Fermi GBM observation
  25. GRB 231118A: Fermi GBM observation
  26. LIGO/Virgo/KAGRA S231119ab: Coverage and upper limits from MAXI/GSC observations
  27. GRB 231117A: Swift-XRT refined Analysis
  28. GRB 231118A: Swift-XRT refined Analysis
  29. GRB 231118A: MeerLICHT afterglow detection
  30. LIGO/Virgo/KAGRA S231119u: One counterpart neutrino candidate from IceCube neutrino searches
  31. GRB 231117A: OHP/T120 optical observations
  32. GRB 231118A: VLT/X-shooter redshift
  33. Fermi trigger No 722039659: Global MASTER-Net observations report
  34. GRB 231117A: Pan-STARRS1 follow-up confirms rapid fading
  35. LIGO/Virgo/KAGRA S231119u: Identification of a GW compact binary merger candidate
  36. GRB 231117A: AKO Follow-Up Observation
  37. GRB 231118A: Las Cumbres optical detection
  38. GRB 231118B: BALROG localization (Fermi Trigger 722039659 / GRB 231118940)
  39. GRB 231118A: LCOGT Optical Observations
  40. GRB 231118A: Enhanced Swift-XRT position
  41. GRB 231117A: Kinder observations with Lulin observatory for AT 2023yba without fading in r band
  42. GRB 231118A: Skynet Optical Afterglow Discovery
  43. LIGO/Virgo/KAGRA S231118an: Identification of a GW compact binary merger candidate
  44. GRB 231117A: GRBAlpha detection
  45. LIGO/Virgo/KAGRA S231118ab: Identification of a GW compact binary merger candidate
  46. GRB 231115A: Wendelstein Optical/Infrared Observations
  47. GRB 231115A: JinShan optical upper limits
  48. LIGO/Virgo/KAGRA S231118d: Identification of a GW compact binary merger candidate
  49. GRB 231117A: GIT optical follow-up
  50. GRB 231117A: LT observations consistent with fading
  51. GRB 231117A: REM optical and NIR early-time observations
  52. GRB 231117A: AKO Optical Upper Limit
  53. GRB 231117A: afterglow candidate detection from Kinder observations with Lulin observatory
  54. GRB 231117A (short): Glowbug gamma-ray detection
  55. GRB 231117A: ATLAS non-detection of an optical counterpart
  56. GRB 231115A : OHP/T120 optical upper limit
  57. GRB 231117A : MITSuME Akeno optical upper limits
  58. GRB 231117A: Enhanced Swift-XRT position
  59. GRB 231117A: AstroSat CZTI detection of a bright short burst
  60. GRB 231117A: Swift detection of a bright short burst
  61. GRB 231115A: Non-detection of radio emission with CHIME/FRB
  62. GRB 231111A: Swift/UVOT Detection
  63. MAGIC observation of GRB 231115A, a possible magnetar giant flare
  64. GRB231115A: Liverpool Telescope imaging
  65. GRB 231115A: NuSTAR Follow-Up Observations
  66. GRB 231115A: Swift/BAT-GUANO detection of a short burst
  67. GRB 231115A: Swift-XRT and Swift-UVOT observations
  68. GRB 231115A: AGILE/MCAL upper limits
  69. GRB 231115A: Insight-HXMT/HE detection
  70. GRB 231115A: GBM/Fermi Observations of a probable Giant Flare of Magnetar
  71. GRB 231115A : MITSuME Akeno and Okayama optical upper limits
  72. GRB 231115A: Gaoyazi/GOT follow-up and archival observations
  73. GRB 231115A / AT2023xvj: Updated GIT analysis
  74. GRB 231115A: Upper limits from a neutrino search with IceCube
  75. GRB 231115A: Kinder observations with Lulin observatory
  76. GRB231115A: GRANDMA Observations
  77. GRB 231115A: GOTO pre-burst limits of AT2023xvj
  78. GRB 231115A: Non-detection in low-latency of gravitational waves with LIGO/Virgo/KAGRA
  79. GRB 231115A: pre-burst ZTF upper limits for GRB optical counterpart candidate
  80. GRB 231106A: TESS identification of candidate optical counterpart
  81. GRB 231115A (short): Glowbug gamma-ray detection
  82. GRB 231115A: Fermi Observations of a probable Magnetar Giant Flare from M82
  83. GRB 231115A: archival HST observations
  84. GRB 231115A: GROWTH-India discovery of a potential optical counterpart
  85. GRB 231115A: significance of INTEGRAL localization alignment with M82
  86. LIGO/Virgo/KAGRA S231113bw: Updated Sky localization, EM Bright Classification, and Source Classification
  87. GRB 231111A: Swift-BAT refined analysis
  88. LIGO/Virgo/KAGRA S231114n: Updated Sky localization
  89. GRB 231113A (short): Glowbug gamma-ray detection
  90. GRB 231114A (short): Glowbug gamma-ray detection
  91. LIGO/Virgo/KAGRA S231113bw: GROWTH-India coverage and upper limits
  92. GECAM-B observation of a short burst from SGR J1555-5402
  93. LIGO/Virgo S231113bw: upper limits from AGILE/MCAL
  94. LIGO/Virgo/KAGRA S231114n: Identification of a GW compact binary merger candidate
  95. SGRJ1555-5402: Swift/BAT-GUANO arcminute localization of a SGR flare
  96. LIGO/Virgo/KAGRA S231113bw: Upper limits from Fermi-GBM Observations
  97. LIGO/Virgo/KAGRA S231113cd: Coverage and upper limits from MAXI/GSC observations
  98. LIGO/Virgo/KAGRA S231113bb: Updated Sky localization
  99. LIGO/Virgo/KAGRA S231113bw: Coverage and upper limits from MAXI/GSC observations
  100. LIGO/Virgo/KAGRA S231113bw: Identification of a GW compact binary merger candidate

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