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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_MC170219_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"

10959 results found.

  1. EP250427a / GRB 250427A: VLT/X-shooter redshift confirmation z = 1.520
  2. GRB 250424A: PRIME near-infrared detection
  3. GRB 250419A: Mondy Optical Observations
  4. GRB 250424A: Kilonova-Catcher optical afterglow detection
  5. GRB 250407A: GRBAlpha detection
  6. GRB 250404A / EP250404a: GRBAlpha detection
  7. GRB 250330B: GRBAlpha detection
  8. GRB 250424A: VLT/X-shooter spectroscopic redshift z = 0.310
  9. LIGO/Virgo/KAGRA S250328ae: Subaru/PFS Spectroscopic Follow up and Candidates
  10. GRB 250419A: Mondy Continued Optical Observations
  11. The EP-WXT trigger 01709135179: Kinder optical counterpart candidate
  12. GRB 250419A: SVOM/VT optical continuous observations
  13. GRB 250419A: Mondy and AbAO Optical Observations
  14. GRB 250407A: GTC/OSIRIS+ spectroscopic redshift z = 1.36
  15. GRB 250419A: SVOM/VT optical bright counterpart confirmation
  16. GRB 250403A: VLT/FORS2 spectroscopic redshift z = 1.847
  17. GRB 250407A: Mondy and AbAO Optical Observations
  18. GRB 250320B: cubesat Avion detection
  19. GRB 250404A / EP250404a: RC500 INASAN-Kislovodsk optical upper limit
  20. GRB 250404A / EP250404a: Mondy optical observations
  21. GRB 250403A: Montarrenti Observatory optical detection
  22. GRB 250327B: VIRT Optical Upper Limit
  23. GRB 250402A: Mondy optical observations
  24. EP250402a: Optical upper limit with Kinder observations
  25. GRB 250403A: SVOM/VT optical observation
  26. GRB 250402A: VLT/FORS2 spectroscopic redshift z = 2.823
  27. GRB 250402A: SVOM/VT optical counterpart
  28. GRB 250327B: Kilonova-Catcher Observations
  29. GRB250331D: AbAO optical observations
  30. GRB 250328A: AbAO AS-32 Optical Observations
  31. GRB 250322B: GRBAlpha detection
  32. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 2)
  33. GRB 250329A: AbAO, Mondy and SAO RAS optical upper limits
  34. LIGO/Virgo/KAGRA S250328ae: Swift XRT observations, 34 possible X-ray sources
  35. GRB 250328A: Swift/UVOT Detection
  36. GRB 250331A: MAXI/GSC detection
  37. GRB 250328A: A fading optical afterglow confirmed by SVOM/VT
  38. LIGO/Virgo/KAGRA S250328ae: DECam DESGW Candidates (Epoch 1)
  39. GRB 250327B: ALMA detection
  40. GRB 250327B: VLA detection
  41. GRB 250329A: VLT/X-shooter redshift z = 2.921
  42. GRB 250327B: CrAO and SAO RAS Optical Observations
  43. GRB 250322A: GRANDMA/TNOT optical upper limits
  44. GRB 250327B: Las Cumbres optical counterpart detection
  45. FRB 20250316A: Gemini Imaging and Spectroscopy of the Sub-arcsecond Localization Region of FRB 20250316A
  46. EP250321a: Mondy AZT-33IK Continued Optical Observations
  47. GRB 250321B: ISON-Kitab RC-36 Optical Upper Limit
  48. EP-WXT trigger 01709133021: Optical upper limit through Kinder observations
  49. GRB 250322A: Gemini-North redshift of candidate host galaxy
  50. FRB 20250316A: Kinder optical upper limits of the Einstein Probe candidate X-ray source EP J120944.2+585060
  51. EP250321a: Mondy AZT-33IK Optical Observations
  52. FRB 20250316A: detection of a candidate associated X-ray source EP J120944.2+585060 by Einstein Probe
  53. GRB 250320B: Fermi-LAT detection
  54. EP250321a: Kinder optical follow-up observations
  55. GRB 250321A: Swift detection of a burst
  56. GRB 250317B: Mondy AZT-33IK Continued Optical Observations
  57. GRB 250313A: GRBAlpha detection
  58. GRB 250317D: EIRSAT-1 GMOD Detection
  59. GRB 250317B: Mondy AZT-33IK Optical Observations
  60. GRB 250317B: GTC/OSIRIS+ spectroscopic redshift z=3.44
  61. GRB 250316A: AbAO AS-32 Optical Upper Limit
  62. GRB 250314A: GTC z-band upper limit and updated photo-z ~ 7.27
  63. GRB 250314A: EP-FXT afterglow detection
  64. GRB 250312B: GRBAlpha detection
  65. EP250315a: optical counterpart candidate detected by Gemini North
  66. GRB 250314A: VLT/X-shooter dropout, redshift z ~ 7.3
  67. GRB 250226A: Mondy AZT-33IK and Koshka Zeiss-1000 Optical Upper Limits
  68. GRB 250313A: CALET Gamma-Ray Burst Monitor detection
  69. GRB 250313A: SVOM/GRM observation of a bright long burst
  70. GRB 250313A: Fermi-LAT detection
  71. GRB 241213A: VIRT Optical Upper Limit
  72. GRB 241228A: VIRT Optical Upper Limit
  73. GRB 250311A/EP250311a: Optical upper limits with Kinder observations
  74. GRB 250308A: CALET Gamma-Ray Burst Monitor detection
  75. GRB 250311A/MAXI J1457-026: MAXI/GSC detection
  76. GRB 250309B / AT2025dws: OSIRIS+/GTC spectroscopy z=1.898
  77. Fermi-LAT gamma-ray observations of IceCube-250309A
  78. EP250302a: Optical Observations at CrAO and SAO RAS
  79. EP250302a: Mondy Continued Optical Observations
  80. EP250304a: VLT/X-shooter redshift z = 0.200
  81. EP250302a: SVOM/VT optical observation
  82. LIGO/Virgo/KAGRA S250223dk and Swift/BAT-GUANO ID 762004910: Swift/UVOT Upper Limits
  83. EP250302a: SAO RAS optical observations
  84. EP250302a: Kinder optical follow-up observations
  85. EP250302a: Mondy Observations and Optical Light Curve
  86. EP250302a: VLT/MUSE optical redshift z = 1.131
  87. EP250302a: Xinglong F60B optical observation
  88. GRB 250226A: GRANDMA Optical Observations
  89. LIGO/Virgo/KAGRA S250206dm: early X-ray upper limits from Einstein Probe WXT and preliminary results of FXT observations
  90. EP250228a: Optical observations with Kinder and Swift/UVOT
  91. GRB 250225B: EIRSAT-1 GMOD Detection
  92. GRB 250226A: KAO Optical Upper Limit
  93. GRB 250226A: AbAO AS-32 Optical Upper Limit
  94. GRB 250225B: VLT/HAWKI near-infrared observations
  95. EP250227a: Optical upper limits with Kinder observations
  96. GRB 250205A / EP250205A: further radio observations with the VLA
  97. EP250226a / GRB 250226A: SVOM/VT optical observations
  98. EP250226a/GRB 250226A: Kinder optical follow-up observations
  99. EP250223a: CrAO ZTSH optical observation
  100. GRB 250225B: VLT/FORS2 candidate optical afterglow

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