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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"

32693 results found.

  1. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  2. EP241109a: confirmation of a stellar flare by BOOTES-7
  3. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  4. EP241107A: MASTER optical observations of xray transient
  5. EP241107a: KAIT optical observations
  6. GRB 241108A: Swift ToO observations
  7. GRB 241030A: TESS observations
  8. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  9. EP241107a: Kinder optical follow-up observations
  10. GRB 241025A: radio detection with the VLA
  11. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  12. EP241107a: AKO Optical Afterglow Follow-Up Observations
  13. EP241107a: GSP detects optical counterpart
  14. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  15. GRB 241105A: EP-FXT follow-up observations
  16. GRB 241105A: SVOM/GRM observation
  17. EP241107a: OHP/T193 photometric and spectroscopic observations
  18. GRB 241105a: PRIME near-infrared upper limits
  19. EP241107a: FTW Optical and NIR observations of the optical counterpart
  20. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  21. EP241107a: GIT optical observations
  22. EP241107a: Global MASTER-Net observations report
  23. EP241107a: SVOM/C-GFT optical observations
  24. EP241107a: AKO Optical Afterglow Detection
  25. GRB 241025A: LBT optical observations
  26. GRB241105A: Gemini-South Optical Afterglow Detection
  27. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  28. GRB 241105A: Swift/UVOT Detection
  29. EP241101a: CrAO ZTSH optical observations
  30. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  31. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  32. GRB 241030A: Mondy optical observations
  33. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  34. Konus-Wind detection of GRB 241105A (short with extended emission)
  35. Konus-Wind detection of GRB 241021A
  36. GRB 241105A: SVOM/VT optical afterglow observations
  37. GRB 241105A: Swift-XRT afterglow detection
  38. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  39. GRB 241104A: Swift-XRT observations
  40. GRB 240511A: LCO upper limits
  41. GRB 241104A: Fermi GBM Observation
  42. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  43. GRB 241105A: Swift ToO observations
  44. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  45. GRB 241104A: Swift ToO observations
  46. GRB 241104A: NOT optical non-detection
  47. GRB 241105A: GOTO tentative optical counterpart candidate
  48. Fermi GRB 241105A: Global MASTER-Net observations report
  49. GRB 241104A: SVOM/VT optical candidate
  50. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  51. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  52. GRB 241104A: SVOM/GRM observation
  53. EP241104a: EP detection of GRB 241104A X-ray emission
  54. GRB 241010A: host galaxy redshift z = 0.977
  55. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  56. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  57. GRB 240821A: further radio observations with the VLA
  58. Fermi GRB 241104A: Global MASTER-Net observations report
  59. GRB 241030A: GRBAlpha detection
  60. EP241101a: EP-FXT observations update
  61. EP241103a: GIT optical upper limit
  62. EP241021a: OHP/T193 further optical observations
  63. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  64. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  65. EP241103a: GOTO optical upper limit
  66. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  67. EP241101a: Possible detection of an optical counterpart with FTW
  68. EP241103a: Swift XRT detection and improved X-ray position
  69. EP241021a: continued SOAR observations
  70. EP241101a: Optical upper limits with Kinder observations
  71. EP241101a: OHP/T193 optical observations
  72. EP241103a: Gemini optical limits
  73. EP241103a: EP observation update
  74. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  75. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  76. EP241103a: GSP optical upper limit
  77. EP241103A: LCO optical observations
  78. EP241103a: Global MASTER-Net observations report
  79. GRB 241030A: Rapid release of TESS data.
  80. EP241101a: Global MASTER-Net observations report
  81. GRB 241029A: GRBAlpha detection
  82. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  83. S241102cy: Identification of a GW compact binary merger candidate
  84. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  85. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  86. GRB241030A: OHP/T193 optical observations
  87. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  88. Swift GRB 241101A: Global MASTER-Net observations report
  89. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  90. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  91. EP241021a: Upper limit from Konus-Wind observations
  92. GRB 241101A: Swift-BAT refined analysis
  93. GRB 241030A: further SAO RAS optical observations
  94. GRB 241030A: Optical Observations via Virtual Telescope Project
  95. EP241021a: Liverpool Telescope optical follow-up observations
  96. GRB 241026A: SAO RAS optical observations
  97. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  98. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  99. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  100. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits

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