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Observation Date (UT) Observation Lat

Canonical Name:1ES 1215+303
TeVCat Name:TeV J1217+301
Other Names:ON 325, B2 1215+30, VER J1217+301
Source Type:HBL
R.A.:12 17 48.5 (hh mm ss)
Dec.:+30 06 06 (dd mm ss)
Gal Long: 189.01 (deg)
Gal Lat: 82.05 (deg)
Distance: z=0.131
Flux:0.035 (Crab Units)
Energy Threshold:250 GeV
Spectral Index:
Discovery Date:2011-01
Discovered By: MAGIC
TeVCat SubCat:Default Catalog

Source Notes:

Source position and its uncertainty:
TeV source position added on 131028; prior to that, the position from NED was used
From VERITAS Collaboration (2013):
- R.A. (J2000): 12h 17m 48.5s +/- 1.7s (stat)
- Dec. (J2000): +30d 06' 06" +/- 25"
- Systematic uncertainty: 50"

171017: The redshift was updated from z=0.13 to z=0.131
From Piano et al. 2017:
- "we secured a high quality optical spectrum (SNR approx. 300) in
which we detect two emission lines: [OII] 3727 Angstroms,
[OIII] 5007 Angstroms at z = 0.131 (see also Table 5) confirming
the low redshift previously reported."
Note: in the abstract the redshift is listed as z=0.129; in Table 4
the emission lines are listed as lying at redshift of z=0.129
- White et al. (2000) give z=0.237
- Akiyama et al. (2003) give z=0.130

Triggered observations:
- From ATel 3100: "The MAGIC observations were triggered by
an optical high-state of the source, reported by the Tuorla blazar
monitoring program".

Spectral Properties:
From VERITAS Collaboration (2013):
- Spectral index: 3.6 +/- 0.4(stat) +/- 0.3(syst)
From Aleksic et al. (2012):
- Spectral index: 2.96 +/- 0.14(stat) +/- 0.15(syst)
From Prokoph et al. (2012):
- Spectral index: 3.6 +/- 0.5

Flux :
From VERITAS Collaboration (2013):
- during the 2011 season:
- 3.4% of the Crab Nebula flux
- "no evidence for deviation from a steady flux" was found. "No
significant flux variations within any monthly bin were detected
- data available outside the 2011 season (2008/9 and 2012):
- an upper limit was placed on the TeV flux during 2008/9
- during 2012 a flux at the leve of 1.2% of the Crab Nebula flux was
- "The hypothesis of a constant flux between the three seasons is
excluded at the level of 4.5 sigma."
From Prokoph et al. (2012):
- a flux at the level of about 3% of that of the Crab is reported above 200 GeV
From Aleksic et al. (2012):
- the flux corresponds to about 3.5% of the Crab Nebula flux
From Benbow et al. (2011):
- a flux at the level of 1% that of the Crab is reported
From Mariotti (2011):
- a flux at the level of (2.0 +/- 1.0)% that of the Crab is reported

Initially, this source was classified as an LBL in TeVCat. It has been
updated (121113) to a HBL based on its classification in
the Fermi 2nd AGN Catalog (Ackermann et al. 2012)

Information on the jet:
From Lister et al. (2019):
- "All three innermost features of this low redshift BL Lac object
(z = 0.131) show small but significant inward motion of approximately
25 micro-as y-1 (0.2 c)."

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