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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_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').
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"

10920 results found.

  1. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  2. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources
  3. LIGO/Virgo/KAGRA S251112cm: TROVE Vetting of TNS Candidates
  4. LIGO/Virgo/KAGRA S251112cm: ATLAS pre-detections of AT2025adgp and AT2025adgq
  5. LIGO/Virgo/KAGRA S251112cm: Detection of two young transients by BlackGEM/MeerLICHT: AT2025adgp and AT2025adgq
  6. GRB 251112B: MAXI/GSC detection
  7. LIGO/Virgo/KAGRA S251112cm: Coverage and upper limits from MAXI/GSC observations
  8. GRB 251111A: SVOM/VT optical observations with X-band data
  9. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  10. GRB 251106A: Swift/BAT arcminute localization of a burst
  11. GRB 251106A: MASTER optical observations
  12. GRB 251104A: SVOM detection of a burst
  13. GRB 251103B: MITSuME Akeno optical upper limits
  14. GRB 250926B: VZLUSAT-2 detection
  15. GRB 250926A: VZLUSAT-2 detection
  16. GRB 250925A: VZLUSAT-2 detection
  17. GRB 251026A/EP251026a: SVOM/VT optical counterpart
  18. GRB 251028B: CALET Gamma-Ray Burst Monitor detection
  19. GRB251026B: PRIME H-band upper limit
  20. GRB 251028A: MAXI/GSC detection
  21. GRB 251022A: SVOM/GRM observation
  22. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  23. GRB 251023B / EP251023b: Mondy optical upper limit
  24. GRB 251017A: INASAN-Kislovodsk optical observations
  25. GRB 251026A: Mondy optical upper limit
  26. GRB 251025B: Mondy optical observations
  27. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  28. EP251023a: Mondy optical observations
  29. GRB 251025C: CALET Gamma-Ray Burst Monitor detection
  30. GRB 251025B: MASTER OT detection
  31. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  32. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  33. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  34. GRB 251022A: Fermi GBM Observation
  35. GRB 251023B: CALET Gamma-Ray Burst Monitor detection
  36. GRB 251013C: ISON-Castelgrande observatory optical observations
  37. GRB 251022A: MASTER OT detection
  38. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  39. EP251023a: Einstein Probe detection of an X-ray transient
  40. GRB 251022A: Fermi-LAT detection
  41. GRB 250911A: MAXI/GSC detection
  42. GRB 251017A : RAPAS follow-up observations
  43. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  44. GRB 251018A: MASTER OT detection
  45. GRB 251017A: SVOM/VT optical observation
  46. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  47. Swift Trigger 1404295 is not a GRB
  48. GRB 251016A: CALET Gamma-Ray Burst Monitor detection
  49. GRB 251016B: CALET Gamma-Ray Burst Monitor detection
  50. GRB 251014D: Swift-BAT refined analysis
  51. GRB 251013C: VLA detection
  52. GRB 251014B: PRIME J-band upper limit
  53. GRB 251013C: SVOM/ECLAIRs refined analysis
  54. Swift Trigger 1404295: possible GRB 251015A
  55. GRB 251014B: Swift/UVOT Upper Limits
  56. GRB 251014D: Swift/UVOT Upper Limits
  57. GRB 251011B: SVOM/VT optical upper limit
  58. GRB 251014D: Swift detection of a burst
  59. GRB 251014A: PRIME near-infrared upper limits
  60. GRB 251013C: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an bright optical counterpart
  61. GRB 251013C: Fermi GBM Observation
  62. GRB 251013C NUTTelA-TAO / BSTI Early Measurements
  63. GRB 251013A: CALET Gamma-Ray Burst Monitor detection
  64. GRB 251013C: J band observations by SYSU 80cm infrared telescope
  65. GRB 251013C: ALMA detection
  66. GRB 251013C: SAO RAS optical observations
  67. GRB 251013C: SVOM detection of a burst
  68. GRB 251003A: Mondy optical upper limit
  69. MASTER OT J011025.98-583210.6 : SVOM/VT optical observation
  70. GRB 251011B inspection: MASTER orphan GRB detection
  71. GRB 251011B : MASTER optical observations
  72. GRB 251011B: Swift detection of a burst
  73. GRB 251006A: CALET Gamma-Ray Burst Monitor detection
  74. GRB 251007B - SVOM/ECLAIRs refined analysis
  75. GRB 251002A - SVOM/ECLAIRs refined analysis
  76. EP250911a: Koshka Zeiss-1000 Optical Upper Limit
  77. GRB 251007B: SVOM/VT optical candidate
  78. GRB 251007A: CALET Gamma-Ray Burst Monitor detection
  79. GRB 251005C: PRIME J-band upper limit
  80. GRB 251007B: SVOM/C-GFT upper limit
  81. GRB 251007B: SVOM detection of a faint burst
  82. GRB 251007B: Swift detection of a burst
  83. GRB 251007A: Swift detection of a burst with an optical counterpart
  84. GRB 251005C: SVOM/VT optical fading
  85. GRB 251005C: SVOM/VT optical candidate
  86. GRB 251005C: Swift/UVOT Upper Limits
  87. GRB 250902A: MSU cubesats detection
  88. GRB 251005C: Swift detection of a burst
  89. GRB 251002A: Mondy/AZT-33IK optical observations
  90. GRB 251001B: AbAO optical upper limit
  91. GRB 251002A: AbAO optical observations
  92. GRB 251001C: CALET Gamma-Ray Burst Monitor detection
  93. GRB 251002A: J band observations by SYSU 80cm infrared telescope
  94. GRB 251002A: OHP/T193 MISTRAL optical afterglow detection
  95. GRB 251002A: VLT/X-shooter spectroscopic redshift z = 2.178
  96. GRB 251002A: SVOM detection of a burst
  97. GRB 251001B: SVOM/VT optical observation
  98. GRB 250910A / EP250910a: VLT limits on the possible associated supernova
  99. LIGO/Virgo/KAGRA S250818k: further MeerKAT monitoring
  100. GRB 250910A / EP250910a: VLT/X-shooter host galaxy redshift z = 0.592

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