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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.

"N/A_MC151008_R1" does not adhere to advanced search syntax. Please refer to the documentation and try again.
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"

10927 results found.

  1. EP260507a: Kinder optical counterpart candidate
  2. EP260507a: LCO optical counterpart
  3. GRB 260504B: SVOM/ECLAIRs refined analysis
  4. GRB 260504B: SVOM/VT optical upper limits
  5. GRB 260421B: radio observation with the VLA
  6. GRB 260310A / AT2026fgk: photometric monitoring and tentative maximum of a possible SN
  7. EP260416a: Mondy and Terskol optical upper limits
  8. EP260321a/SN 2026gzf: spectroscopy at Mondy observatory
  9. GRB 260401A: cubesat Avion detection
  10. The EP-WXT trigger 01709258652: Mondy optical observations
  11. GRB 250328A: VLT host galaxy discovery and redshift z = 1.250
  12. EP260416a: Mondy optical observations
  13. EP260416a: ZTSh R band observations
  14. EP250512a / GRB 250512B: VLT/X-shooter host galaxy identification and redshift z = 1.773
  15. GRB 250530A: VLT/X-shooter host galaxy redshift z = 1.486
  16. GRB 260421B: SVOM/VT optical observations
  17. GRB 260415A: CALET Gamma-Ray Burst Monitor detection
  18. GRB 260415B: CALET Gamma-Ray Burst Monitor detection
  19. GRB 260421B: VLT/X-shooter spectroscopic redshift z = 2.115
  20. EP260416a: Optical follow-up observations with Kinder
  21. GOTO26djh/AT2026jpw: CrAO and Mondy optical observations of the transient
  22. EP260416a: VLT/FORS2 spectroscopic redshift confirmation
  23. GOTO26djh/AT2026jpw: ZTSh R,I bands observations of the transient
  24. EP260416a: SVOM/VT optical observation
  25. GOTO26djh/AT2026jpw: SVOM/VT optical observation
  26. GOTO26djh/AT2026jpw transient: SAO RAS optical observations
  27. NOT r-band observations of the transient GOTO26djh/AT2026jpw
  28. EP260321a: CMO SAI J,K observations
  29. EP260321a: SVOM/VT optical observations and color changes around peak
  30. GRB 260410A: CALET Gamma-Ray Burst Monitor detection
  31. The EP-WXT trigger 01709260010 is likely a flaring star
  32. GRB 260411B: Fermi-LAT detection
  33. EP-WXT01709259790: Optical Upper limits with kinder observations
  34. EP260409a: SVOM/VT optical upper limits
  35. GRB 260407A: CALET Gamma-Ray Burst Monitor detection
  36. EP260321a: VLA radio detection
  37. EP260405a: GMOS-N optical upper limits
  38. EP260405a: SVOM/VT optical upper limits
  39. GRB 260330B: SVOM/VT further optical observation
  40. EP260403a: LCO optical observations of the counterpart
  41. GRB 260330B: SVOM/VT optical candidate
  42. GRB 260402A / EP260402a: SVOM/VT optical upper limits
  43. GRB 260401A: CALET Gamma-Ray Burst Monitor detection
  44. GRB 260401A: MAXI/GSC detection
  45. EP260329b: Mondy and Assy-Turgen optical upper limits
  46. GRB 260330B: SVOM/VT optical upper limits
  47. EP260329b: Optical follow-up with Kinder observations
  48. EP260329a: Optical upper limit with Kinder observations
  49. EP260327a: SVOM/VT optical upper limits
  50. EP260327a: Gemini-North optical upper limits
  51. GRB 260310A: OSIRIS+/GTC spectroscopic detection of the associated BL-Ic, SN 2026fgk
  52. GRB 260310A / AT2026fgk: Late-time infrared detection with MIRAGE on the MDM 1.3m telescope
  53. EP260321a: VLT/FORS2 spectroscopy confirmation of an associated type Ic-BL supernova SN 2026gzf
  54. GRB 260310A: LBT optical observations
  55. EP260321A: Mondy optical observations
  56. GRB 260316B: CALET Gamma-Ray Burst Monitor detection
  57. EP260321a / AT2026gzf: VLT/X-shooter detection of supernova-like spectral features at z = 0.0344
  58. EP260321a: Continued brightening from Kinder follow-up of the emerging supernova candidate
  59. EP260321a: VLT imaging and spectroscopy show the variable source to be at z = 0.0343
  60. EP260321a: further Kinder optical observations
  61. GRB 260321A: SVOM/VT optical upper limits
  62. EP260321a: SVOM/VT optical upper limit
  63. GRB 260310A: continued optical observation at Mondy
  64. EP260321a: Kinder observations detect a blue variable star and set limits on a source from the z =0.034 galaxy within the error circle
  65. GRB 260310A: no evidence of re-brightening up to 9.6 days in optical observation at Mondy
  66. GRB 260310A/AT2026fgk: LBT near-infrared observations
  67. GRB 260310A / AT 2026fgk: radio detection with the VLA
  68. GRB 260310A / AT2026fgk: SVOM/VT optical observations
  69. IceCube-260315A/AT2026fpm: EP-FXT follow-up observation
  70. EP260316a / GRB 260316A: SVOM/VT optical upper limits
  71. EP260316a: optical upper limit with Kinder observations
  72. EP260314a: optical upper limit with Kinder observations
  73. EP260314a: SVOM/VT optical candidate
  74. GRB 260310A / AT2026fgk: SAO RAS optical observations
  75. GRB 260310A / AT2026fgk: Multiband optical follow-up with Kinder observations
  76. GRB 260310A: NOT optical polarimetry
  77. GRB 260310A/AT 2026fgk: Bok spectroscopic observation
  78. GRB 260310A / AT2026fgk: OSIRIS+/GTC spectroscopy confirms redshift z = 0.153
  79. GRB 260307A: CALET Gamma-Ray Burst Monitor detection
  80. GRB 260312A: Swift detection of a burst
  81. GRB 260131A/B: radio detection with the VLA
  82. EP260306a: Mondy optical upper limit
  83. GRB 260208A: radio detection with the VLA
  84. GRB 260307B: SVOM/VT upper limit with X band data analysis
  85. GRB 260307B: SVOM/VT optical candidate
  86. EP260302a: SVOM/VT optical observation
  87. EP260306a: Gemini-North redshift z = 4.773
  88. EP260306a: SVOM/VT optical observation
  89. EP260302a: Gemini-South redshift z = 1.535
  90. GRB 260211A: SVOM/VT optical rebrightening at 20 days after the burst, SN candidate
  91. GRB 260303A: SVOM/VT optical observations
  92. GRB 260303A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  93. EP260227a: Mondy optical observations
  94. EP260227a: SVOM/VT optical observation
  95. GRB 260228A: SVOM/VT optical upper limits
  96. EP260227A: 3.6m DOT optical afterglow detection
  97. EP260227a: likely GTC/OSIRIS+ redshift z = 2.714
  98. EP260227a: Liverpool Telescope observations
  99. GRB 260225A: SVOM/VT optical continued observations and upper limit
  100. EP/WXT trigger 01709258681 (EP260227a?): LCO candidate afterglow

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