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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.

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').

810 results found.

  1. GRB 250331A: MAXI/GSC detection
  2. EP250311a/GRB 250311A: Correction to EP-WXT detection time
  3. EP250311a/GRB 250311A: EP-FXT follow-up observation
  4. GRB 250311A: Swift-XRT observations
  5. GRB 250311A/EP250311a: TRT optical upper limit
  6. GRB 250311A: Tiled Swift observations
  7. EP250311a/GRB 250311A: EP-WXT detection
  8. GRB 250311A/MAXI J1457-026: MAXI/GSC detection
  9. GRB 250209A: MAXI/GSC detection (possible detection of an X-ray flare from 1RXS J145110.3+310648)
  10. GRB 250207B: Swift-XRT observations
  11. GRB 250207B: Tiled Swift observations
  12. GRB 250207B: MAXI/GSC detection
  13. LIGO/Virgo/KAGRA S250206dm: Coverage and upper limits from MAXI/GSC observations
  14. LIGO/Virgo/KAGRA S250201i: Coverage and upper limits from MAXI/GSC observations
  15. GRB 250126A: CALET Gamma-Ray Burst Monitor detection
  16. GRB 250126A: MAXI/GSC detection
  17. LIGO/Virgo/KAGRA S241231du: Coverage and upper limit from MAXI/GSC observations
  18. GRB 241213B: Swift-XRT observations
  19. GRB 241213B: Tiled Swift observations
  20. GRB 241213B: CALET Gamma-Ray Burst Monitor detection
  21. GRB 241213B: MAXI/GSC detection
  22. GRB 241207C: MASTER optical observations
  23. GRB 241207C: Tiled Swift observations
  24. GRB 241207C: MAXI/GSC detection
  25. LIGO/Virgo/KAGRA S241114bi: Coverage and upper limits from MAXI/GSC observations
  26. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  27. GRB 240414A: further radio observations with the VLA
  28. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  29. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  30. LIGO/Virgo/KAGRA S240830gn: Coverage and upper limits from MAXI/GSC observations
  31. GRB 240824B: Ondrejov D50 optical limit
  32. GRB 240824B: Fermi GBM Observation
  33. GRB 240824B: Swift-XRT afterglow detection
  34. GRB 240824B: Swift/BAT arcminute localization of a burst
  35. GRB 240824B: MAXI/GSC detection
  36. GRB 240809B: MAXI/GSC detection
  37. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  38. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  39. GRB 240514E: A possible candidate BD-21 1074
  40. MAXI GRB240514.78: Global MASTER-Net observations report
  41. GRB 240514E: MAXI/GSC detection of a probable afterglow
  42. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  43. GRB 240414A: NOEMA detection
  44. LIGO/Virgo/KAGRA S240422ed: Coverage and upper limits from MAXI/GSC observations
  45. GRB 240414A: radio detection with the VLA
  46. GRB 240414A: AMI-LA radio observations
  47. GRB 240414A: LBT optical detection
  48. GRB 240414A: Glowbug gamma-ray detection
  49. GRB 240414A: Swift-BAT refined analysis
  50. GRB 240414A: AbAO optical upprer limit
  51. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  52. GRB 240414A: GMG observation
  53. EP 240414a: BOOTES-4/MET Optical Upper Limits
  54. GRB 240414A: Fermi GBM Observation
  55. GRB 240414A: Photometric observation from 2.2m CAHA
  56. GRB 240414A: Swift/UVOT Detection
  57. GRB 240414A: Mondy optical observations
  58. GRB 240414A: AKO Optical Upper Limit
  59. X-ray transient EP 240414a - GTC spectroscopic observations
  60. EP 240414a: NOT optical counterpart confirmation
  61. GRB 240414A: Swift-XRT refined Analysis
  62. GRB240414A : J-band upper limits from WINTER
  63. GRB 240414A: Enhanced Swift-XRT position
  64. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  65. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  66. GRB 240414A: Skynet Optical Afterglow Observations
  67. Swift GRB 240414A: Global MASTER-Net observations report
  68. GRB 240414A : MITSuME Akeno optical upper limits
  69. GRB 240414A: Redshift confirmation from GTC/OSIRIS+
  70. GRB 240414A : OHP/T193 redshift determination
  71. GRB 240414A : OHP/T193 optical counterpart detection
  72. GRB 240414A: Swift detection of a burst
  73. GRB 240309A: MAXI/GSC detection
  74. GRB 240225B: Swift-XRT afterglow detection
  75. GRB 240225B: Glowbug gamma-ray detection
  76. GRB 240225B: Swift ToO observations
  77. Konus-Wind detection of GRB 240225B (long)
  78. GRB 240225B: VLT/X-shooter redshift
  79. GRB 240225B : MITSuME Akeno optical afterglow candidate detection
  80. GRB 240225B: 3.6m DOT observation
  81. GRB 240225B: NOT optical observations
  82. GRB 240225B: Nanshan/HMT optical afterglow detection
  83. GRB 240225B: CALET Gamma-Ray Burst Monitor detection
  84. GRB 240225B: Swift-XRT observations
  85. GRB 240225B: GOTO detection of a candidate optical afterglow
  86. GRB 240225B: AstroSat CZTI detection
  87. GRB 240225B: Tiled Swift observations
  88. GRB 240225B: MAXI/GSC detection
  89. GRB 240128A: Further Swift-XRT observations
  90. GRB 240214A: Tiled Swift observations
  91. GRB 240214A/1H 0451-560: MAXI/GSC detection
  92. GRB 240128A: Glowbug gamma-ray detection
  93. GRB 240128A: Swift-XRT observations
  94. GRB 240128A: GRBAlpha detection
  95. GRB 240128A: Tiled Swift observations
  96. GRB 240128A: CALET Gamma-Ray Burst Monitor detection
  97. GRB 240128A: MAXI/GSC detection
  98. GRB 240122A: ATCA detection of radio counterpart
  99. GRB240122A: PRIME near infrared detection
  100. GRB 240122A: Swift/UVOT Upper Limits

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