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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.

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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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submitter:"Judith Racusin"

10966 results found.

  1. GRB 250225B: VLT/HAWKI near-infrared observations
  2. EP250227a: Optical upper limits with Kinder observations
  3. GRB 250205A / EP250205A: further radio observations with the VLA
  4. EP250226a / GRB 250226A: SVOM/VT optical observations
  5. EP250226a/GRB 250226A: Kinder optical follow-up observations
  6. EP250223a: CrAO ZTSH optical observation
  7. GRB 250225B: VLT/FORS2 candidate optical afterglow
  8. EP250226a / GRB 250226A: VLT/X-shooter redshift of z = 3.315
  9. LIGO/Virgo S250223dk: Swift XRT observations, 7 X-ray sources
  10. LIGO/Virgo/KAGRA S250223dk and Swift/BAT-GUANO ID 762004910: DECam GW-MMADS candidates
  11. EP250223a: Kinder optical follow-up observations
  12. LIGO/Virgo/KAGRA S250223dk: DECam DESGW Candidates
  13. GRB 250119B: VZLUSAT-2 detection
  14. GRB 250202B: VZLUSAT-2 detection
  15. GRB 250219A: EP-FXT afterglow detection
  16. GRB 250210A: VZLUSAT-2 detection
  17. GRB 250206A: VZLUSAT-2 detection
  18. EP250223a: SVOM/VT optical observation
  19. EP250223a: NOT redshift z = 2.756
  20. EP250223a: NOT optical afterglow candidate
  21. GRB 250221A: continued Assy optical observations, brightening afterglow confirmation
  22. GRB 250221A: continued Mondy optical observations, brightening afterglow
  23. GRB 250221A: Mondy optical observations
  24. GRB 250221A: Assy optical observations
  25. GRB 250221A: VLT/X-shooter redshift z = 0.768
  26. GRB 250221A: GRANDMA/TAROT Detection
  27. GRB 250219A: GRANDMA/Kilonova-Catcher upper limits
  28. EP250220a: Optical upper limit with Kinder observations
  29. GRB 250219A: NOT optical observations
  30. GRB 250219A: SVOM/VT optical counterpart
  31. GRB 250219A: SVOM detection of a burst
  32. GRB 250215A / EP250215A: Encouraging Follow-up Observations of a BdHN I with a Rest-Frame Duration 2.3 s at z=4.61
  33. SVOM/sb25021804: SVOM detection of a long X-ray transient
  34. LIGO/Virgo/KAGRA S250206dm: AZT-33IK Target Optical Observations
  35. LIGO/Virgo/KAGRA S250206dm: observation in AbAO, optical transient near NED/GLADE+ galaxy WISEA J021210.14+514821.7
  36. GRANDMA/OPD observations of GRB250215A
  37. EP250215a / GRB 250215A : NOT optical observations
  38. EP250215a / GRB 250215A (potentially): NOT likely optical counterpart
  39. EP250207b: Xinglong optical upper limit
  40. EP250212a: Xinglong optical upper limit
  41. GRB 250213A: SVOM detection of a burst
  42. GRB 250205A: VIRT Optical Upper Limit
  43. GRB 250210A: GRBAlpha detection
  44. GRB 250205A / EP250205A: radio detection with the VLA
  45. LIGO/Virgo/KAGRA S250206dm: Kinder confirmation of a possible artefact in AT 2025bbo
  46. LIGO/Virgo/KAGRA S250206dm: Gemini-North spectroscopic observation of AT2025bbo and its host galaxy
  47. GRB 241128A: VIRT Optical Upper Limit
  48. EP250207b: Gemini GMOS-N z-band observations
  49. GRB 250209A: MAXI/GSC detection (possible detection of an X-ray flare from 1RXS J145110.3+310648)
  50. GRB 250204B: GRBAlpha detection
  51. GRB 250204A: GRBAlpha detection
  52. LIGO/Virgo/KAGRA S250206dm: Optical observations of candidate AT 2025bbo with Kinder
  53. GRB 250129A: GRANDMA Continued Afterglow Detection
  54. GRB 250206A: EIRSAT-1 GMOD Detection
  55. LIGO/Virgo/KAGRA S250206dm: GOTO counterpart search update - AT2025bar
  56. LIGO/Virgo/KAGRA S250206dm: ATLAS observations of the skymap
  57. LIGO/Virgo/KAGRA S250206dm: GOTO observations of optical candidates AT 2025azn and AT 2025azm
  58. LIGO/Virgo/KAGRA S250206dm: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  59. GRB 250129A: Continued AbAO and Mondy optical observations
  60. LIGO/Virgo/KAGRA S250206dm: SAGUARO Detection of Two Potential Optical Counterparts
  61. GRB 250207B: MAXI/GSC detection
  62. The EP-WXT trigger 01709131290 is likely a flaring star
  63. LIGO/Virgo/KAGRA S250206dm: Coverage and upper limits from MAXI/GSC observations
  64. EP250205a/GRB 250205A: correction to the source localization
  65. EP250205a/GRB 250205A: Einstein Probe observation
  66. GRB 250205A: Redshift from OSIRIS+/GTC z = 3.55
  67. GRB 250205A: SVOM detection of a burst
  68. GRB 250129A: AbAO AS-32 and Mondy AZT-33IK optical observations
  69. GRB 250202C: GRBAlpha detection
  70. GRB 250129A: 7DT Detection and Medium-band SED of Afterglow
  71. LIGO/Virgo/KAGRA S250201i: Coverage and upper limits from MAXI/GSC observations
  72. GRB 250129A: NOT optical observations of continuining activity
  73. GRB 250129A: GRANDMA/TAROT optical afterglow detection
  74. GRB 250127A: EP-FXT second observation epoch and confirmation of the x-ray afterglow fading
  75. GRB 250128B: SAO RAS Zeiss-1000 and CrAO ZTSh optical upper limits
  76. GRB 250127A: CrAO and Terskol optical upper limits
  77. GRB 250128B: NOT optical upper limit
  78. GRB 250129A: OHP/T193 optical and spectroscopy observations
  79. GRB 250129A: NOT optical observations and redshift confirmation
  80. GRB 250129A: VLT/X-shooter redshift of z = 2.151
  81. GRB 250127A: EP-FXT afterglow detection
  82. GRB 241223A: cubesat Avion detection
  83. GRB 250126A: CALET Gamma-Ray Burst Monitor detection
  84. GRB 250126A: MAXI/GSC detection
  85. EP250125a: Optical upper limit with Kinder observations
  86. GRB 250121A: CALET Gamma-Ray Burst Monitor detection
  87. EP250108a: AbAO, CMO and Terskol optical upper limits
  88. GRB 250114A: Swift-BAT refined analysis
  89. LIGO/Virgo S250119cv: Swift XRT observations, 5 X-ray sources
  90. EP250108a/AT 2025kg: NOT spectroscopy in agreement with SN Ic-BL
  91. EP250108a / AT 2025kg: the kangaroo is hopping, evidence for optical rebrightening
  92. GRB 241217A / EP241217B: radio detection with the VLA
  93. Swift Trigger 1282245 is not a GRB
  94. GRB 250116A: Fermi-LAT detection
  95. GRB 250114B: SVOM/VT upper limit
  96. GRB 250114B : MITSuME Akeno optical afterglow candidate detection
  97. GRB 250114A: GRANDMA/TAROT optical afterglow detection
  98. GRB 250114A: VLT/X-shooter spectroscopic redshift z = 4.732
  99. Swift GRB 250114A: Global MASTER-Net observations report
  100. GRB 250114A: Swift detection of a burst with an optical counterpart

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