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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_MC151116_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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subject:"Swift"
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submitter:"Judith Racusin"

10956 results found.

  1. GRB 250702F: GRANDMA observations
  2. IceCube-250706A: COLIBRÍ optical upper limits
  3. GRB 250706B: SVOM/VT optical observation
  4. GRB 250703A: EIRSAT-1 GMOD Detection
  5. EP250704a / GRB 250704B: VLT/X-shooter spectroscopic redshift z = 0.661
  6. GRB 250704A: SVOM/VT optical observation
  7. GRB 250704A: VLT/X-shooter afterglow discovery and spectroscopic redshift z = 1.091
  8. LIGO/Virgo/KAGRA S250704ab: Coverage and upper limits from MAXI/GSC observations
  9. GRB 250704A: SVOM detection of a burst
  10. GRB 250702F: Swift/UVOT Detection
  11. GRB 250702A: CALET Gamma-Ray Burst Monitor detection
  12. GRB 250702F: Fermi GBM Observation
  13. GRB 250424A: VIRT Optical Upper Limit
  14. EP250702a/GRB 250702B, C, D, E: EP-FXT follow-up observation
  15. GRB 250702B,C,D,E / EP 250702a: MAXI/GSC detection
  16. GRB 250702F: COLIBRÍ Observations of the Afterglow
  17. GRB 250702F: GTC/OSIRIS+ spectroscopic redshift z = 1.520
  18. GRB 250702F: NOT observations of the optical afterglow
  19. GRB 250702F: Swift detection of a burst with an optical counterpart
  20. GRB 250628B: SVOM/VT optical upper limit
  21. GRB 250628A: VLT/X-shooter upper limits
  22. GRB 250625A: AbAO and INASAN Kislovodsk Optical Observations
  23. GRB 250625A: GTC/OSIRIS+ spectroscopic observations of the potential host galaxy
  24. GRB 250625A: Fermi-LAT detection
  25. GRB 250617B: Mondy and SAO RAS optical observations on 2025-06-23, 2025-06-24
  26. GRB 241018A: Maidanak optical observations
  27. sb25061207/GRB 250612D - SVOM/ECLAIRs refined analysis
  28. GRB 250521A: VZLUSAT-2 detection
  29. GRB 250617B: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  30. GRB 250617B: Assy AZT-20 Optical Observations
  31. SVOM sb25061207: AbAO AS-32 Optical Upper Limit
  32. sb25061207: EP-FXT follow-up observation and afterglow candidate
  33. EP250612a / GRB 250612B: SVOM/VT optical candidate
  34. sb25061218: SVOM detection of a X-ray transient
  35. sb25061207: SVOM/VT optical counterpart
  36. sb25061207: SVOM detection of a X-ray transient
  37. GRB 250610B: SVOM/VT optical shallow decay
  38. GRB 250610B: SVOM/GRM analysis
  39. GRB 250610B: EP-FXT follow-up observation and afterglow counterpart
  40. GRB 250610B: SVOM/VT optical counterpart
  41. GRB 250610B: SVOM detection of a long burst
  42. EP250610a: SVOM/VT optical upper limit
  43. GRBAlpha reentry on June 9, 2025
  44. The EP-WXT trigger 01709178283 is likely a flaring star
  45. GRB 250527C: CrAO Optical Upper Limit
  46. GRB 250605A: SVOM/VT optical upper limit
  47. GRB 250605A: Swift detection of a burst
  48. GRB 250601A: PRIME H band upper limit.
  49. GRB 250601A: PRIME J band upper limit.
  50. GRB 250602A: Fermi-LAT detection
  51. GRB 250530A: VLT/HAWK-I NIR counterpart fading
  52. EP#01709177494: SVOM/VT optical observations
  53. GRB 250530A: SVOM/VT optical upper limit
  54. GRB 250527D: CALET Gamma-Ray Burst Monitor detection
  55. GRB 250527C: Swift/UVOT Upper Limits
  56. GRB 250521C (short): Zwicky Transient Facility identification of a possible fast optical transient counterpart
  57. EP250526a: SVOM/VT optical upper limit
  58. GRB 250527B / MAXI J1450-527 : MAXI/GSC detection
  59. GRB 250521A: GRBAlpha detection
  60. GRB 250520A: GRBAlpha detection
  61. The EP-WXT trigger 01709176612: SVOM/VT optical observations
  62. GRB 250521B: EP-FXT follow-up observation and afterglow candidates
  63. GRB 250521D: SVOM/VT optical observations
  64. GRB 250520A: CALET Gamma-Ray Burst Monitor detection
  65. GRB 250521B: SVOM detection of a burst through offline search
  66. IPN triangulation of GRB 250516B
  67. GRB 250520A：SVOM/VT optical candidate
  68. GRB 250516B: GRBAlpha detection
  69. GRB 250520A: Swift detection of a burst
  70. GRB 250515A: NOT classification of GOTO25cqo as a type-Ia SN
  71. GRB 250515A/GOTO25cqo: SVOM/VT optical blue color
  72. EP250511a: Koshka Zeiss-1000 Optical Upper Limit
  73. EP250512a/GRB 250512B refined analysis of the EP-WXT and EP-FXT observations
  74. GRB 250512B/EP250512a: SVOM/VT optical fading
  75. GRB 250512B/EP250512a：SVOM/VT bright optical counterpart
  76. GRB 250507B: GRBAlpha detection
  77. GRB 250506A: GRBAlpha detection
  78. EP250511a: SVOM/VT optical candidate comfirmation
  79. EP250508a: SVOM/VT optical candidate fading
  80. GRB 250506A: NOT optical upper limits
  81. EP250508a: SVOM/VT optical candidate
  82. GRB 250506A: SVOM/VT optical upper limit
  83. GRB 250506A: Swift/UVOT Upper Limits
  84. GRB 250427B : SVOM detection of a burst through offline search
  85. GRB 250507A: SVOM/VT optical upper limit
  86. GRB 250504A: VLT/X-shooter upper limits
  87. GRB 250504A: SVOM/VT upper limit
  88. GRB 250502A: Mondy and Tien-Shan Optical Observations
  89. GRB 250502A: Montarrenti Observatory optical detection
  90. GRB 250502A: NOT optical observations
  91. GRB 250502A: Redshift from OSIRIS+/GTC z = 2.163
  92. GRB 250407A: VZLUSAT-2 detection
  93. GRB 250430A : MITSuME Akeno optical upper limits
  94. GRB 250430A / EP250430a: VLT/X-shooter spectroscopic redshift z = 0.767
  95. GRB 250424A: CALET Gamma-Ray Burst Monitor detection
  96. GRB 250430A: Swift detection of a burst with optical counterpart
  97. EP250427a: Lesedi optical counterpart detection
  98. EP250427a / GRB 250427A: VLT/X-shooter redshift confirmation z = 1.520
  99. GRB 250424A: PRIME near-infrared detection
  100. GRB 250419A: Mondy Optical Observations

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