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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"

45822 results found.

  1. LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
  2. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  3. EP241109a: confirmation of a stellar flare by BOOTES-7
  4. EP241109a: EP on-board trigger and autonomous follow-up observation
  5. GRB 241108A: Swift-XRT observations
  6. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  7. EP241107A: MASTER optical observations of xray transient
  8. EP241107a: KAIT optical observations
  9. GRB 241108A: Swift ToO observations
  10. GRB 241030A: TESS observations
  11. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  12. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  13. EP241107a: Kinder optical follow-up observations
  14. GRB 241025A: radio detection with the VLA
  15. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  16. EP241107a: AKO Optical Afterglow Follow-Up Observations
  17. EP241107a: GSP detects optical counterpart
  18. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  19. GRB 241107A: SVOM/GRM detection of a short burst
  20. GRB 241105A: EP-FXT follow-up observations
  21. GRB 241105A: SVOM/GRM observation
  22. EP241107a: OHP/T193 photometric and spectroscopic observations
  23. GRB 241105a: PRIME near-infrared upper limits
  24. EP241107a: FTW Optical and NIR observations of the optical counterpart
  25. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  26. EP241107a: GIT optical observations
  27. EP241107a: Global MASTER-Net observations report
  28. EP241107a: SVOM/C-GFT optical observations
  29. EP241107a: AKO Optical Afterglow Detection
  30. GRB 241025A: LBT optical observations
  31. GRB241105A: Gemini-South Optical Afterglow Detection
  32. EP241107a: EP on-board trigger and autonomous follow-up observation
  33. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  34. GRB 241105A: Swift/UVOT Detection
  35. EP241101a: CrAO ZTSH optical observations
  36. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  37. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  38. GRB 241105A: BOOTES-7 optical detection
  39. GRB 241030A: Mondy optical observations
  40. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  41. Konus-Wind detection of GRB 241105A (short with extended emission)
  42. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  43. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  44. Konus-Wind detection of GRB 241021A
  45. GRB 241105A: SVOM/VT optical afterglow observations
  46. GRB 241105A: Swift-XRT afterglow detection
  47. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  48. GRB 241104A: Swift-XRT observations
  49. GRB 240511A: LCO upper limits
  50. GRB 241104A: Fermi GBM Observation
  51. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  52. GRB 241105A: Swift ToO observations
  53. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  54. GRB 241104A: Swift ToO observations
  55. GRB 241104A: NOT optical non-detection
  56. GRB 241105A: GOTO tentative optical counterpart candidate
  57. Fermi GRB 241105A: Global MASTER-Net observations report
  58. GRB 241104A: SVOM/VT optical candidate
  59. GRB 241105A: Fermi GBM Final Real-time Localization
  60. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  61. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  62. GRB 241104A: SVOM/GRM observation
  63. EP241104a: EP detection of GRB 241104A X-ray emission
  64. GRB 241010A: host galaxy redshift z = 0.977
  65. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  66. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  67. GRB 240821A: further radio observations with the VLA
  68. Fermi GRB 241104A: Global MASTER-Net observations report
  69. GRB 241104A: Fermi GBM Final Real-time Localization
  70. GRB 241030A: GRBAlpha detection
  71. EP241101a: EP-FXT observations update
  72. EP241103a: GIT optical upper limit
  73. EP241021a: OHP/T193 further optical observations
  74. LIGO/Virgo/KAGRA S241104a: Retraction of GW compact binary merger candidate
  75. Fermi trigger No 752365806: Global MASTER-Net observations report
  76. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  77. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  78. EP241103a: GOTO optical upper limit
  79. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  80. EP241101a: Possible detection of an optical counterpart with FTW
  81. EP241103a: Swift XRT detection and improved X-ray position
  82. EP241021a: continued SOAR observations
  83. EP241101a: Optical upper limits with Kinder observations
  84. EP241101a: OHP/T193 optical observations
  85. EP241103a: Gemini optical limits
  86. EP241103a: EP observation update
  87. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  88. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  89. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  90. EP241103a: GSP optical upper limit
  91. EP241103A: LCO optical observations
  92. EP241103a: Global MASTER-Net observations report
  93. EP241103a: an X-ray transient detected by Einstein Probe
  94. GRB 241030A: Rapid release of TESS data.
  95. EP241101a: Global MASTER-Net observations report
  96. GRB 241029A: GRBAlpha detection
  97. EP241101a: BOOTES-7 optical upper limit
  98. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  99. S241102cy: Identification of a GW compact binary merger candidate
  100. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume

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