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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

21975 results found.

  1. GRB 241113A: Swift/UVOT Detection
  2. GRB 241113A: REM detection of the optical/NIR afterglow
  3. GRB 241113B: Swift ToO observations
  4. GRB 241113A: LCO optical observations
  5. GRB241113A: LCOGT (40-cm) optical counterpart detection
  6. Swift GRB241113.33: Global MASTER-Net observations report
  7. Fermi trigger No 753166198: Global MASTER-Net observations report
  8. GRB 241105A: ATCA Radio Upper Limits
  9. GRB 241112B: AbAO optical upper limit
  10. GRB 241107A: GROWTH-India telescope optical upper limit
  11. IceCube Alert 241113.02: Global MASTER-Net observations report
  12. Fermi GRB 241112A: Global MASTER-Net observations report
  13. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  14. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  15. GRB 241112B: Swift-XRT afterglow detection
  16. GRB 241112B: SVOM/VT afterglow detection
  17. GRB 241112B: Mephisto optical upper limits
  18. GRB 241112B: GOTO optical upper limits
  19. GRB 241112B: Swift ToO observations
  20. EP241107a: EP-FXT follow-up observations
  21. LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume
  22. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  23. Fermi trigger No 752990530: Global MASTER-Net observations report
  24. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  25. Fermi trigger No 752878030: Global MASTER-Net observations report
  26. Integral GRB241109.89: Global MASTER-Net observations report
  27. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  28. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  29. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  30. LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
  31. EP241109a: confirmation of a stellar flare by BOOTES-7
  32. EP241109a: EP on-board trigger and autonomous follow-up observation
  33. GRB 241108A: Swift-XRT observations
  34. EP241107A: MASTER optical observations of xray transient
  35. EP241107a: KAIT optical observations
  36. GRB 241108A: Swift ToO observations
  37. GRB 241030A: TESS observations
  38. EP241107a: Kinder optical follow-up observations
  39. GRB 241025A: radio detection with the VLA
  40. EP241107a: AKO Optical Afterglow Follow-Up Observations
  41. EP241107a: GSP detects optical counterpart
  42. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  43. GRB 241105A: EP-FXT follow-up observations
  44. EP241107a: OHP/T193 photometric and spectroscopic observations
  45. GRB 241105a: PRIME near-infrared upper limits
  46. EP241107a: FTW Optical and NIR observations of the optical counterpart
  47. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  48. EP241107a: GIT optical observations
  49. EP241107a: Global MASTER-Net observations report
  50. EP241107a: SVOM/C-GFT optical observations
  51. EP241107a: AKO Optical Afterglow Detection
  52. GRB 241025A: LBT optical observations
  53. GRB241105A: Gemini-South Optical Afterglow Detection
  54. EP241107a: EP on-board trigger and autonomous follow-up observation
  55. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  56. GRB 241105A: Swift/UVOT Detection
  57. EP241101a: CrAO ZTSH optical observations
  58. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  59. GRB 241105A: BOOTES-7 optical detection
  60. GRB 241030A: Mondy optical observations
  61. GRB 241105A: SVOM/VT optical afterglow observations
  62. GRB 241105A: Swift-XRT afterglow detection
  63. GRB 241104A: Swift-XRT observations
  64. GRB 240511A: LCO upper limits
  65. GRB 241105A: Swift ToO observations
  66. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  67. GRB 241104A: Swift ToO observations
  68. GRB 241104A: NOT optical non-detection
  69. GRB 241105A: GOTO tentative optical counterpart candidate
  70. Fermi GRB 241105A: Global MASTER-Net observations report
  71. GRB 241104A: SVOM/VT optical candidate
  72. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  73. GRB 241010A: host galaxy redshift z = 0.977
  74. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  75. GRB 240821A: further radio observations with the VLA
  76. Fermi GRB 241104A: Global MASTER-Net observations report
  77. EP241101a: EP-FXT observations update
  78. EP241103a: GIT optical upper limit
  79. EP241021a: OHP/T193 further optical observations
  80. Fermi trigger No 752365806: Global MASTER-Net observations report
  81. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  82. EP241103a: GOTO optical upper limit
  83. EP241101a: Possible detection of an optical counterpart with FTW
  84. EP241103a: Swift XRT detection and improved X-ray position
  85. EP241021a: continued SOAR observations
  86. EP241101a: Optical upper limits with Kinder observations
  87. EP241101a: OHP/T193 optical observations
  88. EP241103a: Gemini optical limits
  89. EP241103a: EP observation update
  90. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  91. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  92. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  93. EP241103a: GSP optical upper limit
  94. EP241103A: LCO optical observations
  95. EP241103a: Global MASTER-Net observations report
  96. EP241103a: an X-ray transient detected by Einstein Probe
  97. GRB 241030A: Rapid release of TESS data.
  98. EP241101a: Global MASTER-Net observations report
  99. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  100. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A

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