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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').
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"

3335 results found.

  1. EP251222a: Einstein Probe detection of an X-ray transient
  2. The EP-WXT trigger 01709250397 is likely a flaring star
  3. EP251221a: Global MASTER-Net observations report
  4. EP251221a: NOT optical upper limit
  5. EP251220a: VLT/FORS2 spectroscopic redshift z = 2.375
  6. EP251220a: NOT optical observations
  7. EP251221a: Einstein Probe detection of a fast X-ray transient
  8. EP251220a: EP-FXT follow-up observation
  9. EP 251220a: GOTO optical counterpart detection
  10. EP 251220a: COLIBRÍ detection of the optical counterpart
  11. EP251220a: Global MASTER-Net observations report
  12. EP251220a: EP detection of a fast X-ray transient
  13. EP251214b: KAIT optical upper limit
  14. EP251214a: Optical upper limit with Kinder observations
  15. EP251214b: Global MASTER-Net observations report
  16. EP251214b : Einstein Probe detection of a fast X-ray transient
  17. EP251214b : Einstein Probe detection of a fast X-ray transient
  18. EP251214b (EP trigger 01709250023): LCO optical limits
  19. EP251214a: KAIT optical upper limit
  20. EP251214a: EP-FXT non-detection and upper limit
  21. EP251214a: Global MASTER-Net observations report
  22. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  23. EP251212a: Global MASTER-Net observations report
  24. EP251212a: KAIT optical upper limit
  25. EP251212a: EP-FXT follow-up observation
  26. EP251212a: Einstein Probe detection of an X-ray transient
  27. EP251124a: Mondy optical upper limit
  28. EP251118a / GRB 251118C: VLT/MUSE redshift confirmation
  29. EP-WXT trigger 01709249380: KAIT confirmation of a stellar flare
  30. EP-WXT trigger 01709249380: confirmation of a stellar flare by BOOTES-5
  31. The EP-WXT trigger 01709249380 is likely a flaring star
  32. Konus-Wind detection of GRB 251118A
  33. GRB 251202A / EP251202a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm and 1-m telescopes at McDonald Observatory
  34. GRB 251202A: SVOM/GRM observation
  35. GRB 251203C: EP-FXT follow-up observation
  36. GRB 251129A/EP251129a : SVOM/ECLAIRs refined analysis
  37. EP251202a / GRB 251202A: Insight-HXMT/HE detection
  38. EP251130a: MAO/AZT-22 optical observations
  39. GRB 251202A / EP251202a: SVOM/VT optical observation
  40. EP251130a: ULL-ASTRO-MASTER late detection of the optical afterglow with LCO 1-m telescope at Teide Observatory
  41. GRB251129A/EP251129a: Swift UVOT detection
  42. GRB 251202A: Swift/UVOT Detection
  43. GRB 251122A/EP251122a: CrAO ZTSh optical observations
  44. EP251202a / GRB 251202A: LCO r- and i-band optical detection
  45. EP251202a/GRB 251202A: refined analysis of the EP-WXT observations
  46. GRB 251202A: Swift-XRT afterglow detection
  47. EP251129a/GRB 251129A: NOWT Detection
  48. EP251130a: SVOM/VT optical observation
  49. EP251202a / GRB 251202A: NOT spectroscopic redshift z = 2.785
  50. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  51. EP251202a/trigger 01709249064: Las Cumbres discovery of the optical counterpart
  52. EP251118a: Mondy, CrAO, Assy and SAO RAS/Zeiss-1000 optical observations
  53. EP251130a: Optical detections with Kinder observations
  54. EP251130a: GTC OSIRIS+ redshift z = 4.035 and rebrightening
  55. EP251130A: Optical observation from 1.3m DFOT
  56. EP251130a: refined analysis of the EP-WXT and EP-FXT observations
  57. EP251130a: Swift-XRT counterpart detection
  58. EP251130a: Global MASTER-Net observations report
  59. EP251130a: COLIBRÍ optical counterpart candidate
  60. EP251130a: Einstein Probe detection of an X-ray transient
  61. EP251129a/GRB 251129A: EP-FXT follow-up observations
  62. GRB 251129A / EP251129a: GTC/OSIRIS+ spectroscopic redshift z = 1.460
  63. GRB 251129A / EP251129a: OSN and CAHA optical follow-up
  64. GRB 251129A: Swift-XRT afterglow detection
  65. The EP-WXT trigger 01709248941 is triggered by the known source Perseus Cluster
  66. GRB 251129A / EP251129a: SVOM/VT optical fading
  67. EP251129a: Global MASTER-Net observations report
  68. EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
  69. EP251124a: Pan-STARRS ri-band imaging and photometry
  70. EP251124b follow-up observation by EP-FXT
  71. EP251124b: NOT r- and z-band optical upper limits
  72. EP251124b: Global MASTER-Net observations report
  73. EP251124b: EP-WXT detection of a fast X-ray transient
  74. EP251124a: Xinglong GWAC-F60A optical observation
  75. EP251124a (EP-WXT trigger 01709248862) is triggered by the known source AWM 7
  76. EP251124a: NOT r- and z-band optical upper limits
  77. EP251124a: Global MASTER-Net observations report
  78. EP251124a: Swift-XRT observations
  79. EP251124a: Optical upper limit with Kinder observations
  80. EP251118A: 6 GHz VLA Detection
  81. LIGO/Virgo/KAGRA S251105aj: SVOM/VT optical observations and preliminary results on SVOM J2320.0-2901
  82. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
  83. EP251124a: GROWTH-India Telescope optical upper limits
  84. EP251124a: Einstein Probe detection of an X-ray transient
  85. GRB 251122A/EP251122a: FTW optical and NIR observations
  86. GRB 251122A/EP251122A: 1.3m DFOT optical detection
  87. The EP-WXT trigger 01709248783 is likely a flaring star
  88. GRB 251122A / EP251122a: Xinglong 2.16m optical observation
  89. GRB 251122A / EP251122a: EP-FXT counterpart detection
  90. EP251122a: refined analysis of the EP-WXT and EP-FXT observations
  91. GRB 251122A/EP251122a: SVOM/VT optical observations with VHF data
  92. GRB 251122A/EP251122a: Additional, deeper LCO optical r band upper limit
  93. GRB 251122A / EP251122a: LCO optical upper limits
  94. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  95. EP251122a: Global MASTER-Net observations report
  96. GRB 251122A/EP251122a: SVOM/C-GFT upper limit
  97. GRB 251122A / EP251122a: SVOM detection of a long burst
  98. EP251122a: Einstein Probe detection of an X-ray transient
  99. EP251118a: Continued Optical Detection with Kinder observations
  100. LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search

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