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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"

45728 results found.

  1. GRB 241030B: TESS detection of optical counterpart
  2. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  3. LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
  4. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  5. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  6. Fermi trigger No 752878030: Global MASTER-Net observations report
  7. Integral GRB241109.89: Global MASTER-Net observations report
  8. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  9. EP241109a: KAIT photometry and 3 m Shane spectroscopy from Lick observatory
  10. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  11. INTEGRAL detection of a burst from 1E 1841-045
  12. EP241107a: AbAO optical upper limit
  13. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  14. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  15. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  16. LIGO/Virgo/KAGRA S241109bn: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  18. EP241109a: confirmation of a stellar flare by BOOTES-7
  19. EP241109a: EP on-board trigger and autonomous follow-up observation
  20. GRB 241108A: Swift-XRT observations
  21. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  22. EP241107A: MASTER optical observations of xray transient
  23. EP241107a: KAIT optical observations
  24. GRB 241108A: Swift ToO observations
  25. GRB 241030A: TESS observations
  26. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  27. GRB 241108A : a likely weak long GRB detected by SVOM/ECLAIRs
  28. EP241107a: Kinder optical follow-up observations
  29. GRB 241025A: radio detection with the VLA
  30. GRB 241104A: CALET Gamma-Ray Burst Monitor detection
  31. EP241107a: AKO Optical Afterglow Follow-Up Observations
  32. EP241107a: GSP detects optical counterpart
  33. EP241107a: Gemini-South spectroscopic confirmation (z = 0.456)
  34. GRB 241107A: SVOM/GRM detection of a short burst
  35. GRB 241105A: EP-FXT follow-up observations
  36. GRB 241105A: SVOM/GRM observation
  37. EP241107a: OHP/T193 photometric and spectroscopic observations
  38. GRB 241105a: PRIME near-infrared upper limits
  39. EP241107a: FTW Optical and NIR observations of the optical counterpart
  40. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  41. EP241107a: GIT optical observations
  42. EP241107a: Global MASTER-Net observations report
  43. EP241107a: SVOM/C-GFT optical observations
  44. EP241107a: AKO Optical Afterglow Detection
  45. GRB 241025A: LBT optical observations
  46. GRB241105A: Gemini-South Optical Afterglow Detection
  47. EP241107a: EP on-board trigger and autonomous follow-up observation
  48. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  49. GRB 241105A: Swift/UVOT Detection
  50. EP241101a: CrAO ZTSH optical observations
  51. GRB 241105A: Swift/BAT-GUANO refined analysis of short burst with extended emission
  52. GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
  53. GRB 241105A: BOOTES-7 optical detection
  54. GRB 241030A: Mondy optical observations
  55. GRB 241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  56. Konus-Wind detection of GRB 241105A (short with extended emission)
  57. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  58. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  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 241105A: Fermi GBM Final Real-time Localization
  75. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  76. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  77. GRB 241104A: SVOM/GRM observation
  78. EP241104a: EP detection of GRB 241104A X-ray emission
  79. GRB 241010A: host galaxy redshift z = 0.977
  80. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  81. GRB 241104A : Detection and localization by SVOM/ECLAIRs
  82. GRB 240821A: further radio observations with the VLA
  83. Fermi GRB 241104A: Global MASTER-Net observations report
  84. GRB 241104A: Fermi GBM Final Real-time Localization
  85. GRB 241030A: GRBAlpha detection
  86. EP241101a: EP-FXT observations update
  87. EP241103a: GIT optical upper limit
  88. EP241021a: OHP/T193 further optical observations
  89. LIGO/Virgo/KAGRA S241104a: Retraction of GW compact binary merger candidate
  90. Fermi trigger No 752365806: Global MASTER-Net observations report
  91. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  92. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  93. EP241103a: GOTO optical upper limit
  94. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  95. EP241101a: Possible detection of an optical counterpart with FTW
  96. EP241103a: Swift XRT detection and improved X-ray position
  97. EP241021a: continued SOAR observations
  98. EP241101a: Optical upper limits with Kinder observations
  99. EP241101a: OHP/T193 optical observations
  100. EP241103a: Gemini optical limits

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