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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"

32716 results found.

  1. GRB 241112B: Mephisto optical upper limits
  2. GRB 241112B: GOTO optical upper limits
  3. GRB 241112B: Swift ToO observations
  4. GRB 241107A: INTEGRAL IBIS localization
  5. EP241107a: EP-FXT follow-up observations
  6. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  7. GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
  8. LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
  9. IPN triangulation of GRB 241107A (short/hard)
  10. GRB 241107A: INTEGRAL/IBIS/PICsIT detection of a short burst
  11. GRB 241025C: VZLUSAT-2 detection
  12. GRB 241025A: VZLUSAT-2 detection
  13. GRB 241018A: cubesat Avion detection
  14. GRB 241030B: TESS detection of optical counterpart
  15. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  16. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  17. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  18. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  19. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  20. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  21. EP241107a: AbAO optical upper limit
  22. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  23. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  24. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  25. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  26. EP241109a: confirmation of a stellar flare by BOOTES-7
  27. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  28. EP241107A: MASTER optical observations of xray transient
  29. EP241107a: KAIT optical observations
  30. GRB 241108A: Swift ToO observations
  31. GRB 241030A: TESS observations
  32. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  33. EP241107a: Kinder optical follow-up observations
  34. GRB 241025A: radio detection with the VLA
  35. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  36. EP241107a: AKO Optical Afterglow Follow-Up Observations
  37. EP241107a: GSP detects optical counterpart
  38. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  39. GRB 241105A: EP-FXT follow-up observations
  40. GRB 241105A: SVOM/GRM observation
  41. EP241107a: OHP/T193 photometric and spectroscopic observations
  42. GRB 241105a: PRIME near-infrared upper limits
  43. EP241107a: FTW Optical and NIR observations of the optical counterpart
  44. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  45. EP241107a: GIT optical observations
  46. EP241107a: Global MASTER-Net observations report
  47. EP241107a: SVOM/C-GFT optical observations
  48. EP241107a: AKO Optical Afterglow Detection
  49. GRB 241025A: LBT optical observations
  50. GRB241105A: Gemini-South Optical Afterglow Detection
  51. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  52. GRB 241105A: Swift/UVOT Detection
  53. EP241101a: CrAO ZTSH optical observations
  54. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  55. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  56. GRB 241030A: Mondy optical observations
  57. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  58. Konus-Wind detection of GRB 241105A (short with extended emission)
  59. Konus-Wind detection of GRB 241021A
  60. GRB 241105A: SVOM/VT optical afterglow observations
  61. GRB 241105A: Swift-XRT afterglow detection
  62. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  63. GRB 241104A: Swift-XRT observations
  64. GRB 240511A: LCO upper limits
  65. GRB 241104A: Fermi GBM Observation
  66. GRB 241104A: The SVOM/VT candidate in GCN circular 38086 is not an astrophysical source
  67. GRB 241105A: Swift ToO observations
  68. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  69. GRB 241104A: Swift ToO observations
  70. GRB 241104A: NOT optical non-detection
  71. GRB 241105A: GOTO tentative optical counterpart candidate
  72. Fermi GRB 241105A: Global MASTER-Net observations report
  73. GRB 241104A: SVOM/VT optical candidate
  74. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  75. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  76. GRB 241104A: SVOM/GRM observation
  77. EP241104a: EP detection of GRB 241104A X-ray emission
  78. GRB 241010A: host galaxy redshift z = 0.977
  79. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  80. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  81. GRB 240821A: further radio observations with the VLA
  82. Fermi GRB 241104A: Global MASTER-Net observations report
  83. GRB 241030A: GRBAlpha detection
  84. EP241101a: EP-FXT observations update
  85. EP241103a: GIT optical upper limit
  86. EP241021a: OHP/T193 further optical observations
  87. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  88. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  89. EP241103a: GOTO optical upper limit
  90. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  91. EP241101a: Possible detection of an optical counterpart with FTW
  92. EP241103a: Swift XRT detection and improved X-ray position
  93. EP241021a: continued SOAR observations
  94. EP241101a: Optical upper limits with Kinder observations
  95. EP241101a: OHP/T193 optical observations
  96. EP241103a: Gemini optical limits
  97. EP241103a: EP observation update
  98. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  99. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  100. EP241103a: GSP optical upper limit

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