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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

28289 results found.

  1. LIGO/Virgo/KAGRA S240919bn: Upper limits from Swift/BAT-GUANO
  2. NuEm-240926A / IC240926A: BZQJ0955+4532 ~0.6m optical decay and rebrightening detection by MASTER
  3. GRB 240926A: SVOM/GRM observation
  4. Konus-Wind detection of GRB 240905B
  5. EP240919a / GRB 240919A: SVOM/VT upper limit
  6. LIGO/Virgo/KAGRA S240925n: NED Galaxies in the Localization Volume
  7. EP240918b and EP240918c: EP-FXT follow-up observations
  8. LIGO/Virgo/KAGRA S240925n: Updated Sky localization and Source Classification
  9. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  10. GRB 240716A: Swift/BAT-GUANO localization skymap of a long burst
  11. LIGO/Virgo/KAGRA S240925n: Identification of a GW compact binary merger candidate
  12. GRB 240905B: VZLUSAT-2 detection
  13. LIGO/Virgo/KAGRA S240922df: Updated Sky localization
  14. LIGO/Virgo/KAGRA S240920dw: Updated Sky localization
  15. LIGO/Virgo/KAGRA S240921cw: Updated Sky localization
  16. LIGO/Virgo/KAGRA S240924a: Updated Sky localization
  17. LIGO/Virgo/KAGRA S240920bz: Updated Sky localization and Source Classification
  18. LIGO/Virgo/KAGRA S240923ct: Updated Sky localization and Source Classification
  19. LIGO/Virgo/KAGRA S240924a: Identification of a GW compact binary merger candidate
  20. LIGO/Virgo/KAGRA S240923ct: Identification of a GW compact binary merger candidate
  21. LIGO/Virgo S240919bn: Swift XRT observations, 10 X-ray sources
  22. GRB 240918B: AstroSat CZTI detection
  23. LIGO/Virgo/KAGRA S240922df: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo/KAGRA S240921cw: Identification of a GW compact binary merger candidate
  25. EP240913A/GRB 240913C: AbAO optical upper limit
  26. EP240919a / GRB 240919A: Mondy optical upper limit
  27. EP240913a/GRB 240913C: 1.6m Mephisto observations
  28. EP240918a: SVOM/VT upper limit
  29. Fermi GBM Sub-Threshold Detection of GRB240919A / EP240919a
  30. EP240919a / GRB 240919A: REM optical and NIR upper limits
  31. EP240918b and EP240918c: Optical upper limits with Kinder observations
  32. GRB 240414A: further radio observations with the VLA
  33. EP240919a: Optical upper limit with Kinder observations
  34. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  35. GRB 240910A: radio detection with the VLA
  36. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  37. EP240919a: NOT and Gemini optical observations
  38. EP240919a: GOTO optical upper limits
  39. EP240919a: JinShan optical upper limits
  40. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  41. LIGO/Virgo/KAGRA S240919bn: Updated Sky localization
  42. GRB 240918B: Fermi GBM Detection
  43. LIGO/Virgo/KAGRA S240917cb: Updated Sky localization and EM Bright Classification
  44. LIGO/Virgo/KAGRA S240916ar: Updated Sky localization and EM Bright Classification
  45. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  46. GRB 240910A: further Swift observations and confirmation of afterglow
  47. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  48. EP240918a: Swift-XRT observation
  49. EP240918a: JinShan optical upper limits
  50. EP240918a: Optical upper limits with Kinder observations
  51. EP240918a: GMG Optical Upper Limit
  52. EP240918a: an X-ray transient detected by Einstein Probe
  53. GRB 240912A: Swift-BAT refined analysis
  54. IPN triangulation of GRB 240913C / EP 240913a
  55. GRB 240916A: Fermi GBM Observation
  56. LIGO/Virgo/KAGRA S240917cb: Identification of a GW compact binary merger candidate
  57. GRB 240821A: radio observation with the VLA
  58. GRB 240916A: Swift-XRT afterglow detection
  59. LIGO/Virgo/KAGRA S240916ar: Identification of a GW compact binary merger candidate
  60. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  61. LIGO/Virgo S240915b: Swift XRT observations, 8 X-ray sources
  62. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  63. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  64. LIGO/Virgo/KAGRA S240915bd: Updated Sky localization
  65. EP240913a: VLT/HAWK-I near-infrared upper limits
  66. LIGO/Virgo/KAGRA S240915bd: Identification of a GW compact binary merger candidate
  67. LIGO/Virgo/KAGRA S240915b: Updated Sky localization and EM Bright Classification
  68. LIGO/Virgo/KAGRA S240915b: Identification of a GW compact binary merger candidate
  69. GRB 240913C: Fermi GBM detection
  70. GRB 240914A: Swift-XRT observations
  71. GRB 240910A: SVOM/VT optical observations
  72. EP240913a: NOT optical upper limits
  73. EP240913a: JinShan optical upper limits
  74. EP240913a: ESO-NTT optical observations
  75. GRB 240914A: ESO-NTT optical observations
  76. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  77. GRB 240905E: further NOT optical observations
  78. EP240913a: EP-WXT detection of a fast X-ray transient
  79. GRB 240911A: LCO optical observations
  80. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  81. GRB 240912A: Swift/UVOT Detection
  82. GRB 240911A: Swift-XRT observations
  83. GRB 240912A: J-band observations with WINTER
  84. GRB 240912A: Swift-XRT refined Analysis
  85. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  86. GRB 240912A: Enhanced Swift-XRT position
  87. GRB 240912A: Redshift from OSIRIS+/GTC
  88. Fast X-ray Transient EP240801a: GMRT radio observations
  89. GRB 240912A: Swift detection of a burst with an optical counterpart
  90. GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
  91. GRB 240910A: JinShan optical observations
  92. IPN triangulation of GRB 240905B (short)
  93. GRB 240825A: 7DT Optical Upper Limit
  94. GRB 240905E: SVOM/VT optical observations
  95. LIGO/Virgo/KAGRA S240910ci: NED Galaxies in the Localization Volume
  96. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  97. LIGO/Virgo/KAGRA S240910ci: Updated Sky localization and EM Bright Classification
  98. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  99. GRB 240910A: SVOM/GRM observation
  100. EP240908a: Mondy and AbAO follow-up observations

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