diff --git a/README.md b/README.md index 1007f33..df7dc77 100644 --- a/README.md +++ b/README.md @@ -6,8 +6,6 @@ book for a given target. - **[TELESCOPES.md](TELESCOPES.md)**: the full review, grouped by observatory, with a "choosing a telescope" guide at the end. -- **[TARGETS.md](TARGETS.md)**: southern-sky targets invisible from the UK, matched - to scopes and to the time of year to book them. - **[data/itelescope-telescopes.csv](data/itelescope-telescopes.csv)**: snapshot of the network's maintained specs sheet (source of truth for the numbers). - **state/**: project state under the Default Workflow. diff --git a/TARGETS.md b/TARGETS.md deleted file mode 100644 index 1bc0d83..0000000 --- a/TARGETS.md +++ /dev/null @@ -1,155 +0,0 @@ -# Southern targets: what the UK can never show you - -A target guide for imaging objects that are invisible (or hopeless) from the UK, -using the southern half of the iTelescope network: Siding Spring, Australia (Q62) -and Deep Sky Chile (X07). Companion to [TELESCOPES.md](TELESCOPES.md). - -## The visibility rule from the UK - -From latitude 51.5°N (southern England), an object's maximum altitude is -`90° - 51.5° + declination`: - -- **Dec below about -38°: never rises.** These objects cannot be imaged from the UK - at all, ever. -- **Dec -25° to -38°: technically rises, practically hopeless.** Culminates under - ~15° altitude, buried in atmosphere and murk. -- Dec -10° to -25°: imageable from the UK but always low and compromised; far better - from the southern sites. - -Everything below is grouped by those tiers, then matched to scopes and to the time -of year when it is best placed from the southern sites. - -## Tier 1: never visible from the UK (dec < -38°) - -### The Magellanic Clouds (the headline act) - -| Target | Dec | Best scope | Notes | -|---|---|---|---| -| Large Magellanic Cloud | -69° | T8 | The whole LMC just fits T8's 4 x 4 degree field | -| Tarantula Nebula (NGC 2070) | -69° | T73, T17 | Core detail; the finest emission nebula in either sky | -| Small Magellanic Cloud + 47 Tucanae | -72° | T8 | Both in a single T8 frame, a unique composition | -| 47 Tucanae (NGC 104) alone | -72° | T33 (free), T73 | Second-finest globular in the sky | - -### Carina and Crux region - -| Target | Dec | Best scope | Notes | -|---|---|---|---| -| Eta Carinae Nebula (NGC 3372) | -59° | T71 | Fills T71's 2.7 x 1.8 degree field perfectly; narrowband showpiece | -| Carina to Crux widefield | -60° | T70 | The richest stretch of the Milky Way in one 8-degree frame | -| Southern Pleiades (IC 2602) | -64° | T71, T75 | Bright open cluster | -| Running Chicken (IC 2944) | -63° | T71, T75 | Emission nebula with Bok globules | -| Wishing Well Cluster (NGC 3532) | -58° | T71 | Reportedly the best open cluster in the sky | -| Coalsack + Southern Cross | -60° | T70 | Dark nebula composition | - -### Centaurus and the southern globulars - -| Target | Dec | Best scope | Notes | -|---|---|---|---| -| Omega Centauri (NGC 5139) | -47° | T59, T17 | The largest globular cluster known; needs the ~40 arcmin fields | -| Centaurus A (NGC 5128) | -43° | T17, T32, T73 | Iconic dust-lane radio galaxy | -| NGC 4945 | -49° | T73 | Big edge-on spiral, underimaged | -| NGC 6752 (Pavo globular) | -60° | T33 (free) | Third-brightest globular | - -### Ara, Norma and the Scorpius tail - -| Target | Dec | Best scope | Notes | -|---|---|---|---| -| Fighting Dragons of Ara (NGC 6188) | -49° | T71 | Dramatic narrowband target | -| Prawn Nebula (IC 4628) | -40° | T71, T75 | Large, faint, great in Ha | -| NGC 6231 + Table of Scorpius | -42° | T71 | Rich cluster region | - -### Far-southern galaxies - -| Target | Dec | Best scope | Notes | -|---|---|---|---| -| NGC 6744 (Pavo) | -63° | T73, T17 | Milky Way lookalike spiral | -| NGC 1313 (Topsy-Turvy) | -66° | T73 | Distorted starburst spiral | -| NGC 1566 (Spanish Dancer) | -55° | T73 | Grand-design face-on spiral | -| NGC 2070 region galaxies | -69° | T17 | See Magellanic section | - -### Southern nebulae, supernova remnants and planetaries - -| Target | Dec | Best scope | Notes | -|---|---|---|---| -| Vela SNR | -45° | T70 | Huge filamentary shell, needs the 8-degree field | -| Gum Nebula | -43° | T70 | 36 degrees across; even T70 mosaics it | -| Southern Ring (NGC 3132) | -40° | T73 | Small bright planetary | -| Toby Jug Nebula (IC 2220) | -59° | T73 | Reflection nebula | - -## Tier 2: hopeless from the UK (dec -25° to -38°), excellent from the south - -| Target | Dec | Best scope | Notes | -|---|---|---|---| -| Cat's Paw (NGC 6334) | -36° | T71 | Narrowband showpiece | -| War and Peace (NGC 6357) | -34° | T71 | Pairs with the Cat's Paw in one T75 framing | -| NGC 1365 (Great Barred Spiral) | -36° | T73, T17 | The archetypal barred spiral, Fornax | -| Fornax cluster core | -35° | T17, T32 | Galaxy cluster field | -| M83 (Southern Pinwheel) | -30° | T73, T17 | Face-on spiral, superb from Q62/X07 | -| NGC 300 and NGC 55 (Sculptor) | -37°/-39° | T17, T75 | Nearby resolved spirals | -| NGC 253 (Sculptor Galaxy) | -25° | T17, T32 | Huge dusty starburst, low and ruined from the UK | -| Corona Australis dust complex | -37° | T71, T75 | Reflection nebula and dust river | - -## When to book what (from the southern sites) - -Seasons refer to what is well placed in the evening-to-midnight sky at Siding Spring -and Deep Sky Chile. Siding Spring scopes have 30-35 degree minimum elevation limits, -so aim within a few hours of culmination; T70 in Chile can go to the horizon. - -- **Jan-Mar:** Tarantula and the LMC, NGC 1313, Vela SNR and the Gum Nebula, Carina - rising late evening. -- **Apr-Jun:** Eta Carinae at its best, Crux and the Coalsack, Omega Centauri, - Centaurus A, NGC 4945, the Musca dark nebulae. -- **Jul-Sep (now):** the Scorpius tail and Ara at the zenith: Cat's Paw, War and - Peace, Prawn, NGC 6188, NGC 6231; NGC 6744; Corona Australis; 47 Tucanae and the - SMC in the second half of the night. -- **Oct-Dec:** Magellanic Cloud prime time, 47 Tucanae, Sculptor galaxies (NGC 253, - 55, 300), Fornax cluster and NGC 1365, NGC 1566. - -## A sensible first campaign (July-August) - -1. **Free warm-up on T33** (30 min/day, Siding Spring): 47 Tucanae or NGC 6752 in - LRGB across a few nights. Costs nothing, learns the booking system. -2. **T71 narrowband run** (Chile, f/2.8): NGC 6188 or the Cat's Paw + War and Peace - region. Fast optics keep the bill down; use the standard 300 s calibrated subs. -3. **T73 galaxy shot**: NGC 6744, currently well placed, as an LRGB target. -4. **Book ahead for October-November:** T8 for the LMC (or SMC + 47 Tuc in one - frame): the single most "you cannot do this from the UK" image on the network. - -## Budgeting a points balance - -Published rate shape (from itelescope.net/standard-plans, 2026-07): affordable -scopes roughly $19-54 per imaging hour, premium scopes roughly $54-118 per hour, -where the range is the moon-phase discount (dark of moon at the top of the range, -bright moon at the bottom) and the plan discount (10% on Plan-40, 20% on Plan-90). -Exact per-scope, per-night rates are shown in the login portal's planner; treat the -numbers below as planning estimates, not quotes. - -What a ~2,600 point balance buys, roughly: - -- **A strong narrowband image on a fast scope (T71, T75):** 2-3 hours of exposure - is plenty at f/2.8-f/3.8; booked around gibbous moon the rate is at the low end, - so call it 150-350 points per finished target. -- **An LRGB galaxy on T73 or T17:** wants dark-of-moon time at premium-scope rates; - 3-4 hours, roughly 300-500 points per target. -- **The T8 Magellanic Cloud shot:** 2-3 hours LRGB at a mid-range rate, roughly - 200-350 points. - -So ~2,600 points is comfortably 8-12 finished showpiece targets, or a full year of -the seasonal calendar above at one or two targets a month. Stretch it further with: - -- **Full moon weeks are free** on the standard plans: use them for bright globulars - and clusters (47 Tuc, NGC 3532, IC 2602) where moonlight matters least, and keep - paid time for faint stuff. -- **The daily free 30 minutes** (T33 south, T68 north) for framing tests and short - targets, never spend points discovering a framing mistake. -- **Moon-phase arbitrage:** book narrowband (Carina, Ara, Cat's Paw) at bright moon - when rates bottom out; the 3 nm filters do not care about moonlight. - -## Cost-shape notes - -- Fast scopes (T71 f/2.8, T75 f/3.8, T70 f/3.5) reach depth in the least imaging - time, which is what you pay for: prefer them for nebulae. -- The two free scopes cover both hemispheres of this list poorly (T68 is northern) - but T33 covers southern globulars and compact targets well. -- Moonlight: narrowband targets (Carina, Ara, Scorpius nebulae) tolerate moon; - save galaxy and globular time (T73, T17, T8 LRGB) for dark-of-moon bookings. diff --git a/state/TODO.md b/state/TODO.md index e699da8..c0fe66a 100644 --- a/state/TODO.md +++ b/state/TODO.md @@ -9,9 +9,6 @@ - 2026-07-17: specs sheet snapshotted to data/itelescope-telescopes.csv (24 scopes). - 2026-07-17: TELESCOPES.md written: per-scope reviews for all 23 active telescopes plus a choosing guide (T74 noted as in commissioning, no specs published). -- 2026-07-18: TARGETS.md written: southern targets invisible from the UK (dec tiers - from lat 51.5°N), matched to Q62/X07 scopes, seasonal booking calendar, and a - July-August starter campaign (T33 free, T71 narrowband, T73 galaxy, T8 LMC later). ## In progress