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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"

32723 results found.

  1. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  2. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  3. GRB 241112B: SVOM/GRM observation
  4. GRB 241112B: SVOM/VT afterglow detection
  5. Fermi Gamma-ray Burst Monitor trigger 752995908/241111230 (GRB 241111A) is not a GRB
  6. GRB 241107A: Swift/BAT candidate arcminute localization of a short burst
  7. GRB 241112B: Mephisto optical upper limits
  8. GRB 241112B: GOTO optical upper limits
  9. GRB 241112B: Swift ToO observations
  10. GRB 241107A: INTEGRAL IBIS localization
  11. EP241107a: EP-FXT follow-up observations
  12. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  13. GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
  14. LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
  15. IPN triangulation of GRB 241107A (short/hard)
  16. GRB 241107A: INTEGRAL/IBIS/PICsIT detection of a short burst
  17. GRB 241025C: VZLUSAT-2 detection
  18. GRB 241025A: VZLUSAT-2 detection
  19. GRB 241018A: cubesat Avion detection
  20. GRB 241030B: TESS detection of optical counterpart
  21. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  22. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  23. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  24. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  25. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  26. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  27. EP241107a: AbAO optical upper limit
  28. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  29. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  30. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  31. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  32. EP241109a: confirmation of a stellar flare by BOOTES-7
  33. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  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. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  39. EP241107a: Kinder optical follow-up observations
  40. GRB 241025A: radio detection with the VLA
  41. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  42. EP241107a: AKO Optical Afterglow Follow-Up Observations
  43. EP241107a: GSP detects optical counterpart
  44. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  45. GRB 241105A: EP-FXT follow-up observations
  46. GRB 241105A: SVOM/GRM observation
  47. EP241107a: OHP/T193 photometric and spectroscopic observations
  48. GRB 241105a: PRIME near-infrared upper limits
  49. EP241107a: FTW Optical and NIR observations of the optical counterpart
  50. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  51. EP241107a: GIT optical observations
  52. EP241107a: Global MASTER-Net observations report
  53. EP241107a: SVOM/C-GFT optical observations
  54. EP241107a: AKO Optical Afterglow Detection
  55. GRB 241025A: LBT optical observations
  56. GRB241105A: Gemini-South Optical Afterglow Detection
  57. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  58. GRB 241105A: Swift/UVOT Detection
  59. EP241101a: CrAO ZTSH optical observations
  60. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  61. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  62. GRB 241030A: Mondy optical observations
  63. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  64. Konus-Wind detection of GRB 241105A (short with extended emission)
  65. Konus-Wind detection of GRB 241021A
  66. GRB 241105A: SVOM/VT optical afterglow observations
  67. GRB 241105A: Swift-XRT afterglow detection
  68. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  69. GRB 241104A: Swift-XRT observations
  70. GRB 240511A: LCO upper limits
  71. GRB 241104A: Fermi GBM Observation
  72. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  73. GRB 241105A: Swift ToO observations
  74. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  75. GRB 241104A: Swift ToO observations
  76. GRB 241104A: NOT optical non-detection
  77. GRB 241105A: GOTO tentative optical counterpart candidate
  78. Fermi GRB 241105A: Global MASTER-Net observations report
  79. GRB 241104A: SVOM/VT optical candidate
  80. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  81. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  82. GRB 241104A: SVOM/GRM observation
  83. EP241104a: EP detection of GRB 241104A X-ray emission
  84. GRB 241010A: host galaxy redshift z = 0.977
  85. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  86. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  87. GRB 240821A: further radio observations with the VLA
  88. Fermi GRB 241104A: Global MASTER-Net observations report
  89. GRB 241030A: GRBAlpha detection
  90. EP241101a: EP-FXT observations update
  91. EP241103a: GIT optical upper limit
  92. EP241021a: OHP/T193 further optical observations
  93. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  94. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  95. EP241103a: GOTO optical upper limit
  96. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  97. EP241101a: Possible detection of an optical counterpart with FTW
  98. EP241103a: Swift XRT detection and improved X-ray position
  99. EP241021a: continued SOAR observations
  100. EP241101a: Optical upper limits with Kinder observations

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