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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

"N/A_MC170720_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"

10921 results found.

  1. GRB251221A: 7DT optical upper limits
  2. GRB 251222A / EP251222b: SVOM/VT optical rebrightening
  3. GRB 251222A: PRIME near-infrared detection
  4. EP251220a: PRIME upper limit
  5. GRB 251221A: PRIME near-infrared observation
  6. GRB 251221A: UAFO and Mondy optical upper limit
  7. GRB 251220A: MAXI/GSC detection
  8. IceCube-251218A: COLIBRÍ optical upper limits
  9. GRB 251214B: VIRT Optical Upper Limit
  10. GRB 251202A/EP251202a: Koshka optical upper limit
  11. GRB 251214B: Mondy optical upper limit
  12. EP251214a: Optical upper limit with Kinder observations
  13. GRB 251214B: UAFO optical upper limit
  14. GRB 251202A: radio detection with the VLA
  15. GRB 251214B: AbAO optical observations
  16. GRB 251203B: AbAO optical observations
  17. GRB 251214B : MASTER optical afterglow detection
  18. GRB 251214B: Swift detection of a burst with an optical counterpart
  19. EP251124a: Mondy optical upper limit
  20. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  21. EP251130a: Mondy and AbAO optical observations
  22. GRB 251208B: Fermi-LAT detection
  23. GRB 251206A: SVOM detection of a burst through offline search
  24. GRB 251205A : MITSuME Akeno optical afterglow candidate detection
  25. GRB 251205A: Swift/UVOT Detection
  26. GRB 251203C: Swift/UVOT Upper Limit
  27. GRB 251205A: Zeiss-1000 Koshka observatory optical observations
  28. GRB 251205A: NOT optical observations
  29. GRB 251205A: GTC/OSIRIS+ redshift z = 1.100
  30. Swift GRB 251205A : MASTER OT detection with host galaxy
  31. GRB 251205A: Swift detection of a burst with an optical afterglow
  32. GRB 251203C: SVOM/ECLAIRs refined analysis
  33. GRB 251203C: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  34. GRB 251203C: LCO optical afterglow confirmation
  35. GRB 251203C: SVOM/VT optical counterpart
  36. GRB 251203B : SVOM trigger sb25120304 is not a GRB
  37. GRB 251203C: LCO optical upper limits
  38. GRB 251203B: LCO optical upper limits
  39. GRB 251203C: SVOM detection of a burst
  40. GRB 251203B: SVOM detection of a burst
  41. GRB 251129A / EP251129a: SVOM/VT optical color bluer
  42. GRB 251202A / EP251202a: SVOM/VT optical observation
  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 251126A: SAO RAS optical marginal detection
  47. GRB 251126A: SVOM/VT optical observation
  48. EP251130a: SVOM/VT optical observation
  49. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  50. GRB 251201B: SVOM/VT optical fading
  51. Swift GRB 251201B : MASTER optical counterpart detection
  52. EP251118a: Mondy, CrAO, Assy and SAO RAS/Zeiss-1000 optical observations
  53. EP251130a: Mondy optical observations
  54. EP251130a: Optical detections with Kinder observations
  55. EP251130a: GTC OSIRIS+ redshift z = 4.035 and rebrightening
  56. GRB 251201A: MAXI/GSC detection
  57. GRB 251129A / EP251129a: OSN and CAHA optical follow-up
  58. GRB 251129A / EP251129a: SAO RAS optical observations
  59. GRB 251126A: SAO RAS optical observations
  60. SVOM GRB 251129A : MASTER optical counterpart detection
  61. Swift trigger 1418333 is not an astrophysical source
  62. GRB 251129A / EP251129a: SVOM/VT optical fading
  63. GRB 251129A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  64. GRB 251126A: TShAO, Mondy, and AbAO optical observations
  65. GRB 251126A: OHP/T193 optical observations and tentative spectroscopic redshift
  66. GRB 251126A: further SAO RAS optical observations
  67. GRB 251126A: Mondy and SAO RAS optical observations
  68. GRB 251126A : MITSuME Akeno optical afterglow candidate detection
  69. GRB 251125B: COLIBRÍ further observations and photometric redshift upper limit of z < 3
  70. EP251124b follow-up observation by EP-FXT
  71. EP251124b: NOT r- and z-band optical upper limits
  72. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  73. EP251124a: Xinglong GWAC-F60A optical observation
  74. EP251124a (EP-WXT trigger 01709248862) is triggered by the known source AWM 7
  75. EP251124a: NOT r- and z-band optical upper limits
  76. LIGO/Virgo/KAGRA S251112cm: AT 2025adht Kinder follow-up observations
  77. EP251124a: Optical upper limit with Kinder observations
  78. LIGO/Virgo/KAGRA S251105aj: SVOM/VT optical observations and preliminary results on SVOM J2320.0-2901
  79. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
  80. EP251124a: Einstein Probe detection of an X-ray transient
  81. GRB 251122A / EP251122a: Xinglong 2.16m optical observation
  82. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  83. EP251118a: Continued Optical Detection with Kinder observations
  84. LIGO/Virgo/KAGRA S251105aj: SVOM/ECLAIRs detection of a high-energy transient SVOM J2320.0-2901 through targeted search
  85. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  86. EP251118a: Optical detection with Kinder observations
  87. EP-WXT trigger 01709248403: confirmation of a stellar flare by SVOM/VT
  88. LIGO/Virgo/KAGRA S251112cm: SVOM/VT optical observations and preliminary results
  89. EP251118a / GRB 251118C: SVOM/VT optical observation
  90. GRB 251118C: Swift/BAT rates detection of a burst with a possible association with EP 251118A
  91. EP251118A / GRB 251118C : MASTER optical counterpart observations
  92. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  93. GRB 251117A: Fermi-LAT detection
  94. GRB 251116C: Swift/BAT arcminute localization of a burst
  95. GRB 251116B: SVOM/VT optical upper limit
  96. EP251023a: Assy AZT-20 optical observations
  97. EP251023a: UAFO and AbAO optical observations
  98. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  99. GRB 251116C: SVOM/VT optical upper limit
  100. GRB 251025B: further Mondy optical observations

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